Surgery

PreTest® Self-Assessment and Review

PRE TEST®

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PRE TEST®

Surgery

PreTest® Self-Assessment and Review

Ninth Edition

PETER L.GELLER, M.D.

Associate Professor of Clinical Surgery

Columbia University College of Physicians & Surgeons

New York, New York

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DOI: 10.1036/0071376380

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v

CONTENTS

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

PRE- AND POSTOPERATIVE CARE

Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . . 16

CRITICAL CARE:ANESTHESIOLOGY, BLOOD GASES,

RESPIRATORY CARE

Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . . 47

SKIN:WOUNDS, INFECTIONS, BURNS;HANDS;

PLASTIC SURGERY

Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . . 73

TRAUMA AND SHOCK

Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . . 98

TRANSPLANTS, IMMUNOLOGY,AND ONCOLOGY

Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 135

ENDOCRINE PROBLEMS AND BREAST

Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 165

GASTROINTESTINALTRACT, LIVER,AND PANCREAS

Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181

Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 208

Terms of Use

CARDIOTHORACIC PROBLEMS

Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239

Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 252

PERIPHERALVASCULAR PROBLEMS

Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265

Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 277

UROLOGY

Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287

Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 291

ORTHOPEDICS

Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297

Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 301

NEUROSURGERY

Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307

Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 312

OTOLARYNGOLOGY

Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319

Answers, Explanations, and References . . . . . . . . . . . . . . . . . . . . . 322

Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325

vi Contents

Terms of Use

PREFACE

No longer can students assume that this kind of continuing education ends

with the completion of formal training and the successful completion of

licensing or certifying examinations. As of October 1979, all 22 member

boards of the American Board of Medical Specialties committed themselves

to the principle of periodic recertification of their members. Despite the

Board's recognition that the cognitive skills measured in the objective

examination do not assure clinical competence, recertification efforts-

insofar as they involve examinations-are based on the assumption that

knowledge of current information on which good clinical decisions should

be made is worth cultivating; that, while such information does not guarantee

competent practice, lack of it probably impedes competent practice,

that this knowledge, unlike technical skills, is reasonably easy to assess;

and that it can be acquired by well-motivated physicians. These assumptions

all seem reasonable.

The questions presented in this book deal with issues of relative

importance to medical students; other problem-oriented materials are

becoming available that are aimed at more sophisticated audiences-

groups that, within a very few years, will include the present generation of

students. Regular review of such material is a habit worth developing. We

hope that this edition of Surgery: PreTest® Self-Assessment and Review will

justify your efforts in working through the problems by providing guidance

for further study and by helping you to develop enduring learning habits.

PETER L.GELLER, M.D.

vii

INTRODUCTION

Each question in Surgery: PreTest® Self-Assessment and Review, Ninth Edition,

is accompanied by an answer, a paragraph explanation, and a specific page

reference to either a current journal article, a textbook, or both. A bibliography,

which lists all the sources used in the book, follows the last chapter.

Perhaps the most effective way to use this book is to allow yourself one

minute to answer each question in a given chapter; as you proceed, indicate

your answer beside each question. By following this suggestion, you

will be approximating the time limits imposed by the board examinations.

When you have finished answering the questions in a chapter, you

should then spend as much time as you need verifying your answers and

carefully reading the explanations. Although you should pay special attention

to the explanations for the questions you answered incorrectly, you

should read every explanation. The authors of this book have designed the

explanations to reinforce and supplement the information tested by the

questions. If, after reading the explanations for a given chapter, you feel

you need still more information about the material covered, you should

consult and study the references indicated.

STUDENT REVIEWER

Jeffrey J. Anderegg

The University of Iowa College of Medicine

Iowa City, Iowa

viii

PRE- AND POSTOPERATIVE

CARE

Questions

DIRECTIONS: Each item below contains a question or incomplete

statement followed by suggested responses. Select the one best response to

each question.

1

1. A pregnant woman in her 32nd

wk of gestation is given magnesium

sulfate for pre-eclampsia. The earliest

clinical indication of hypermagnesemia

a. Loss of deep tendon reflexes

b. Flaccid paralysis

c. Respiratory arrest

d. Hypotension

e. Stupor

2. Five days after an uneventful

cholecystectomy, an asymptomatic

middle-aged woman is found to

have a serum sodium level of 120

meq/L. Proper management would

a. Administration of hypertonic saline

solution

b. Restriction of free water

c. Plasma ultrafiltration

d. Hemodialysis

e. Aggressive diuresis with furosemide

3. A 50-year-old patient presents

with symptomatic nephrolithiasis.

He reports that he underwent a

jejunoileal bypass for morbid obesity

when he was 39. One would

expect to find

a. Pseudohyperparathyroidism

b. Hyperuric aciduria

c. "Hungry bone" syndrome

d. Hyperoxaluria

e. Sporadic unicameral bone cysts

4. Following surgery, a patient

develops oliguria. You believe the

patient is hypovolemic, but before

increasing intravenous fluids you

seek corroborative data. This

would include

a. Urine sodium of 28 meq/L

b. Urine chloride of 15 meq/L

c. Fractional excretion of sodium less

than 1

d. Urine/serum creatinine ratio of 20

e. Urine osmolality of 350 mOsm/kg

Terms of Use

5. A 45-year-old woman with

Crohn's disease and a small intestinal

fistula develops tetany during

the 2nd wk of parenteral nutrition.

The laboratory findings include Ca

8.2 meq/L; Na 135 meq/L; K 3.2

meq/L; C1 103 meq/L; PO4 2.4

meq/L; albumin 2.4; pH 7.48; 38

kPa; P 84 kPa; bicarbonate 25

meq/L. The most likely cause of the

patient's tetany is

a. Hyperventilation

b. Hypocalcemia

c. Hypomagnesemia

d. Essential fatty acid deficiency

e. Focal seizure

6. A patient with a nonobstructing

carcinoma of the sigmoid colon is

being prepared for elective resection.

To minimize the risk of postoperative

infectious complications,

your planning should include

a. A single preoperative parenteral

dose of antibiotic effective against

aerobes and anaerobes

b. Avoidance of oral antibiotics to prevent

emergence of Clostridium difficile

c. Postoperative administration for

2-4 days of parenteral antibiotics

effective against aerobes and anaerobes

d. Postoperative administration for

5-7 days of parenteral antibiotics

effective against aerobes and anaerobes

e. Operative time less than 5 h

7. A 70-year-old man with aortic

and mitral valvular regurgitation

undergoes an emergency sigmoid

colectomy and end colostomy for

perforated diverticulitis. His postoperative

course is complicated by

a myocardial infarction and atrial

fibrillation. Four weeks later, he

has improved and requests elective

colostomy closure. You would recommend

a. Discontinuation of antiarrhythmic

and antihypertensive medications

on the morning of surgery

b. Discontinuation of beta-blocking

medications on the day prior to

surgery

c. Control of congestive heart failure

with diuretics and digitalis in

severe cases

d. Administration of prophylactic

antibiotics, other than ampicillin

and gentamicin, for patients with

valvular heart disease who are

undergoing gastrointestinal procedures

e. Postponement of elective surgery

for 6-8 wk after a subendocardial

myocardial infarction

2 Surgery

Items 8-9

A previously healthy 55-yearold

man undergoes elective right

hemicolectomy for a Dukes A cancer

of the cecum. His postoperative

ileus is somewhat prolonged, and

on the fifth postoperative day his

nasogastric tube is still in place.

Physical examination reveals

diminished skin turgor, dry

mucous membranes, and orthostatic

hypotension. Pertinent laboratory

values are as follows:

• Arterial blood gases: pH 7.56; PO2

85 kPa; PCO2 50 kPa

• Serum electrolytes (meq/L): Na+

132; K+ 3.1; C1− 80; HCO3− 42

• Urine electrolytes (meq/L): Na+

2; K− 5; C1− 6

8. The values given above allow

the descriptive diagnosis of

a. Uncompensated metabolic alkalosis

b. Respiratory acidosis with metabolic

compensation

c. Combined metabolic and respiratory

alkalosis

d. Metabolic alkalosis with respiratory

compensation

e. "Paradoxical" metabolic respiratory

alkalosis

9. The most appropriate therapy

for the patient described would be

a. Infusion of 0.9% NaC1 with supplemental

KC1 until clinical signs

of volume depletion are eliminated

b. Infusion of isotonic (0.15 N) HC1

via a central venous catheter

c. Clamping the nasogastric tube to

prevent further acid losses

d. Administration of acetazolamide to

promote renal excretion of bicarbonate

e. Intubation and controlled

hypoventilation on a volumecycled

ventilator to further increase

PCO2

Pre- and Postoperative Care 3

Items 10-11

A 23-year-old woman is

brought to the emergency room

from a halfway house, where she

apparently swallowed a handful of

pills. The patient complains of

shortness of breath and tinnitus,

but refuses to identify the pills she

ingested. Pertinent laboratory values

are as follows:

• Arterial blood gases: pH 7.45; PO2

126 kPa; PCO2 12 kPa

• Serum electrolytes (meq/L): Na+

138; K+ 4.8; C1− 102; HCO3− 8

10. The patient's acid-base disturbance

is best characterized by which

of the following descriptions?

a. Acute respiratory alkalosis, compensated

b. Chronic respiratory alkalosis, compensated

c. Metabolic acids, compensated

d. Mixed metabolic acidosis and respiratory

alkalosis

e. Mixed metabolic acidosis and respiratory

acidosis

11. The most likely cause of the

disturbance in this patient is an

overdose of

a. Phenformin

b. Aspirin

c. Barbiturates

d. Methanol

e. Diazepam (Valium)

12. A 65-year-old man undergoes

a technically difficult abdominoperineal

resection for a rectal cancer

during which he receives three

units of packed red blood cells.

Four hours later in the intensive

care unit he is bleeding heavily from

his perineal wound. Emergency

coagulation studies reveal normal

prothrombin, partial thromboplastin,

and bleeding times. The fibrin

degradation products are not

elevated but the serum fibrinogen

content is depressed and the

platelet count is 70,000/μL. The

most likely cause of the bleeding is

a. Delayed blood transfusion reaction

b. Autoimmune fibrinolysis

c. A bleeding blood vessel in the surgical

field

d. Factor VIII deficiency

e. Hypothermic coagulopathy

13. A 78-year-old man with a

history of coronary artery disease

and an asymptomatic reducible

inguinal hernia requests an elective

hernia repair. You explain to him

that valid reasons for delaying the

proposed surgery include

a. Coronary artery bypass surgery 3

mo earlier

b. A history of cigarette smoking

c. Jugular venous distension

d. Hypertension

e. Hyperlipidemia

4 Surgery

14. A 68-year-old man is admitted

to the coronary care unit with an

acute myocardial infarction. His

postinfarction course is marked by

congestive heart failure and intermittent

hypotension. On the fourth

hospital day, he develops severe

midabdominal pain. On physical

examination, blood pressure is

90/60 mm Hg and pulse is 110

beats/min and regular; the abdomen

is soft with mild generalized tenderness

and distention. Bowel sounds

are hypoactive; stool hematest is

positive. The next step in this

patient's management should be

which of the following?

a. Barium enema

b. Upper gastrointestinal series

c. Angiography

d. Ultrasonography

e. Celiotomy

15. A 30-year-old woman in the

last trimester of pregnancy suddenly

develops massive swelling of

the left lower extremity from the

inguinal ligament to the ankle. The

correct sequence of workup and

treatment should be

a. Venogram, bed rest, heparin

b. Impedance plethysmography, bed

rest, heparin

c. Impedance plethysmography, bed

rest, vena caval filter

d. Impedance plethysmography, bed

rest, heparin, warfarin (Coumadin)

e. Clinical evaluation, bed rest, warfarin

16. A 20-year-old woman is found

to have an activated partial thromboplastin

time (APTT) of 78/32 on

routine testing prior to cholecystectomy.

Further investigation reveals

a prothrombin time (PT) of 13/12

(patient/control), a template bleeding

time of 13 min, and a platelet

count of 350 × 100/μL. Which one

of the following characteristics of

this woman's coagulopathy is true?

a. Infusion of purified factor VIII is

usually required to normalize its

concentration prior to surgery

b. Infusion of cryoprecipitate will not

be followed by an improvement in

coagulation

c. Most of these patients are, or

become, seropositive for HIV

d. Epistaxis or menorrhagia is uncommon

e. Lack of platelet aggregation in

response to ristocetin is a common

feature of this disease

17. The chief surgical risk to

which patients with polycythemia

vera are exposed is that due to

a. Anemic disturbances

b. Hemorrhage

c. Infection

d. Renal dysfunction

e. Cardiopulmonary complications

Pre- and Postoperative Care 5

18. A victim of blunt abdominal

trauma requires a partial hepatectomy.

He is rapidly transfused with

8 units of appropriately crossmatched

packed red blood cells

from the blood bank. He is noted in

the recovery room to be bleeding

from intravenous puncture sites

and the surgical incision. His coagulopathy

is likely due to thrombocytopenia

and deficiencies of which

clotting factors?

a. II only

b. II and VII

c. V and VIII

d. IX and X

e. XI and XII

19. Following celiotomy, normal

bowel motility can ordinarily be

presumed to have returned

a. In the stomach in 4 h, the small

bowel in 24 h, and the colon after

the first oral intake

b. In the stomach in 24 h, the small

bowel in 4 h, and the colon in 3

days

c. In the stomach in 3 days, the small

bowel in 3 days, and the colon in 3

days

d. In the stomach in 24 h, the small

bowel in 24 h, and the colon in

24 h

e. In the stomach in 4 h, the small

bowel immediately, and the colon

in 24 h

20. A 65-year-old woman has a

life-threatening pulmonary embolus

5 days following removal of a

uterine malignancy. She is immediately

heparinized and maintained

in good therapeutic range for the

next 3 days, then passes gross

blood from her vagina and develops

tachycardia, hypotension, and

oliguria. Following resuscitation,

an abdominal CT scan reveals a

major retroperitoneal hematoma.

You should now

a. Immediately reverse heparin by a

calculated dose of protamine and

place a vena cava filter (e.g., a

Greenfield filter)

b. Reverse heparin with protamine,

explore and evacuate the

hematoma, and ligate the vena cava

below the renal veins

c. Switch to low-dose heparin

d. Stop heparin and observe closely

e. Stop heparin, give fresh frozen

plasma (FFP), and begin warfarin

therapy

6 Surgery

21. Which of the following surgical

interventions is least likely to

provide acceptable prolongation of

life for patients with AIDS?

a. Splenectomy for AIDS-related idiopathic

thrombocytopenic purpura

b. Colonic resection for perforation

secondary to cytomegalovirus infection

c. Cholecystectomy for acalculous

cholecystitis

d. Tracheostomy for ventilatordependent

patients with respiratory

failure

e. Gastric resection for a bleeding gastric

lymphoma or Kaposi's sarcoma

22. An elderly diabetic woman

with chronic steroid-dependent

bronchospasm has an ileocolectomy

for a perforated cecum. She is

taken to the ICU intubated and is

maintained on broad-spectrum

antibiotics, renal-dose dopamine,

and a rapid steroid taper. On postoperative

day 2 she develops a fever

of 39.2°C (102.5°F), hypotension,

lethargy, and laboratory values

remarkable for hypoglycemia and

hyperkalemia. The most likely

diagnosis of this acute event is

a. Sepsis

b. Hypovolemia

c. Adrenal insufficiency

d. Acute tubular necrosis

e. Diabetic ketoacidosis

23. A cirrhotic patient with abnormal

coagulation studies due to

hepatic synthetic dysfunction

requires an urgent cholecystectomy.

A transfusion of fresh frozen

plasma is planned to minimize the

risk of bleeding due to surgery. The

optimal timing of this transfusion

would be

a. The day before surgery

b. The night before surgery

c. On call to surgery

d. Intraoperatively

e. In the recovery room

24. On postoperative day 3, an

otherwise healthy 55-year-old man

recovering from a partial hepatectomy

is noted to have scant

serosanguineous drainage from his

abdominal incision. His skin staples

are removed, revealing a 1.0-

cm dehiscence of the upper

midline abdominal fascia. Which of

the following actions is most

appropriate?

a. Removing all suture material and

packing the wound with moist sterile

gauze

b. Starting intravenous antibiotics

c. Placing an abdominal (Scultetus)

binder

d. Prompt resuturing of the fascia in

the operating room

e. Bed rest

Pre- and Postoperative Care 7

25. Five days after a sigmoid colectomy

for cancer, a patient's skin staples

are removed and a large gush of

serosanguineous fluid emerges.

Examination of the wound reveals

an extensive fascial dehiscence. The

most appropriate management is

a. Wide opening of the wound to

assure adequate drainage

b. Smear and culture of the fluid and

appropriate antibiotics after the

smear is reviewed

c. Careful reapproximation of the

wound edges with tape

d. Immediate return to the operating

e. Application of a Scultetus binder

26. Signs and symptoms of hemolytic

transfusion reactions include

a. Hypothermia

b. Hypertension

c. Polyuria

d. Abnormal bleeding

e. Hypesthesia at the transfusion site

27. A patient suspected of having

a hemolytic transfusion reaction

should be managed with

a. Removal of nonessential foreign

body irritants, e.g., Foley catheter

b. Fluid restriction

c. 0.1 M HC1 infusion

d. Steroids

e. Fluids and mannitol

28. The surgeon should be particularly

concerned about which coagulation

function in patients receiving

anti-inflammatory or analgesic medications?

a. APTT

b. PT

c. Reptilase time

d. Bleeding time

e. Thrombin time

29. The substrate depleted earliest

in the postoperative period is

a. Branched-chain amino acids

b. Non-branched-chain amino acids

c. Ketone

d. Glycogen

e. Glucose

30. Diagnostic abdominal laparoscopy

is contraindicated in which

of the following patients?

a. A patient with rebound tenderness

following a tangential gunshot

wound to the abdomen

b. A stable patient with a stab wound

to the lower chest wall

c. A patient with a mass in the head of

the pancreas

d. A young female with pelvic pain

and fever

e. An elderly patient in the intensive

care unit suspected of having

intestinal ischemia

8 Surgery

31. A 23-year-old woman undergoes

total thyroidectomy for carcinoma

of the thyroid gland. On the

second postoperative day, she

begins to complain of tingling sensation

in her hands. She appears

quite anxious and later complains

of muscle cramps. Initial therapy

should consist of

a. 10 mL of 10% magnesium sulfate

intravenously

b. Oral vitamin D

c. 100 μg of oral Synthroid

d. Continuous infusion of calcium

gluconate

e. Oral calcium gluconate

32. Hypocalcemia is associated

with

a. Acidosis

b. Shortened QT interval

c. Hypomagnesemia

d. Myocardial irritability

e. Hyperproteinemia

33. The enteric fluid with an electrolyte

(Na+, K+, C1−) content similar

to that of Ringer's lactate is

a. Saliva

b. Contents of small intestine

c. Contents of right colon

d. Pancreatic secretions

e. Gastric juice

34. Which of the following medications

administered for hyperkalemia

counteracts the myocardial

effects of potassium without reducing

the serum potassium level?

a. Sodium polystyrene sulfonate

(Kayexalate)

b. Sodium bicarbonate

c. 50% dextrose

d. Calcium gluconate

e. Insulin

Pre- and Postoperative Care 9

Items 35-37

An in-hospital workup of a 78-

year-old, hypertensive, mildly asthmatic

man who is receiving

chemotherapy for colon cancer

reveals symptomatic gallstones.

Preoperative laboratory results are

notable for a hematocrit of 24%

and a urinalysis with 18-25 WBCs

and gram-negative bacteria. On call

to the operating room he receives

intravenous penicillin. His abdomen

is shaved in the operating

room. An open cholecystectomy is

performed and, despite a lack of

indications, the common bile duct

is explored. The wound is closed

primarily with a Penrose drain exiting

a separate stab wound. On

postoperative day 3 the patient

develops a wound infection.

35. Which of the following changes

could make this wound a less favorable

environment for infection?

a. Decreasing the operative time and

wound contamination by omitting

the common bile duct exploration

b. Placing a Penrose drain exiting

directly through the lateral corner

of the wound

c. Using oral rather than intravenous

penicillin perioperatively

d. Leaving a seroma in the wound to

prevent desiccation of the tissues

e. Reinforcing the wound closure

with a sheet of prosthetic polypropylene

mesh

36. Which of the following characteristics

of this patient might

increase the risk of a wound infection?

a. History of colon surgery

b. Hypertension

c. Male sex

d. Receipt of chemotherapy

e. Asthma

37. Which of the following

changes in the care of this patient

could decrease the chance of a

postoperative wound infection?

a. Increasing the length of the preoperative

hospital stay to prophylactically

treat the asthma with steroids

b. Treating the urinary infection prior

to surgery

c. Shaving the abdomen the night

prior to surgery

d. Continuing the prophylactic antibiotics

for three postoperative days

e. Use of a closed drainage system

brought out through the operative

incision

10 Surgery

Items 38-39

The two solutions most commonly

used to maintain fluid and

electrolyte balance in the postoperative

management of patients are

5% dextrose in 0.9% sodium chloride

and lactated Ringer's solution.

38. A correct statement regarding

5% dextrose in 0.9% saline is

which of the following?

a. It contains the same concentration

of sodium ions as does plasma

b. It can be given in large quantities

without seriously affecting acidbase

balance

c. It is isosmotic with plasma

d. It has a pH of 7.4

e. It may cause a dilutional acidosis

39. Correct statements regarding

lactated Ringer's solution include

which of the following?

a. It contains a higher concentration

of sodium ions than does plasma

b. It is most appropriate for replacement

of nasogastric tube losses

c. It is isosmotic with plasma

d. It has a pH of less than 7.0

e. It may induce a significant metabolic

acidosis

40. Four days after surgical evacuation

of an acute subdural

hematoma, a 44-year-old man

becomes mildly lethargic and

develops asterixis. He has received

2400 mL of 5% dextrose in water

intravenously each day since

surgery, and he appears well

hydrated. Pertinent laboratory values

are as follows:

• Serum electrolytes (meq/L): Na+

118; K+ 3.4; C1− 82; HCO3− 24

• Serum osmolality: 242 mOsm/L

• Urine sodium: 47 meq/L

• Urine osmolality: 486 mOsm/L

A correct statement about this

patient's fluid and electrolyte status

is which of the following?

a. His low serum sodium indicates

sodium deficiency, which should

be treated with 3% saline infusion

b. He probably has the syndrome of

inappropriate secretion of antidiuretic

hormone

c. His blood glucose level should be

checked because the hyponatremia

may be artifactual

d. Water restriction is rarely effective

in severe cases of hyponatremia

e. The underlying problem is the

inappropriate excretion of sodium

(renal sodium wasting)

Pre- and Postoperative Care 11

41. A 43-year-old woman develops acute renal failure following an emergency

resection of a leaking abdominal aortic aneurysm. Three days after

surgery, the following laboratory values are obtained:

• Serum electrolytes (meq/L): Na+ 127; K+ 5.9; C1− 92; HCO3− 15

• Blood urea nitrogen: 82 mg/dL

• Serum creatinine: 6.7 mg/dL

The patient has gained 4 kg since surgery and is mildly dyspneic at

rest. Eight hours after these values are reported, the electrocardiogram

shown below is obtained. The initial treatment for this patient should be

12 Surgery

a. 10% calcium gluconate, 10 mL

b. Digoxin, 0.25 mg every 3 h for three doses

c. Oral Kayexalate

d. Lidocaine, 100 mg

e. Emergent hemodialysis

42. Prophylactic regimens of documented benefit in decreasing the risk of

postoperative thromboembolism include

a. Early ambulation

b. External pneumatic compression devices placed on the upper extremities

c. Elastic stockings

d. Leg elevation for 24 h postoperatively

e. Dipyridamole therapy for 48 h postoperatively

43. Signs and symptoms associated

with early sepsis include

a. Respiratory acidosis

b. Decreased cardiac output

c. Hypoglycemia

d. Increased arteriovenous oxygen difference

e. Cutaneous vasodilation

Pre- and Postoperative Care 13

DIRECTIONS: Each group of questions below consists of lettered

options followed by numbered items. For each numbered item, select the

appropriate lettered option(s). Each lettered option may be used once,

more than once, or not at all. Choose exactly the number of options

indicated following each item.

Items 44-46

Match the gastrointestinal content at each site with its appropriate

ionic composition (meq/L).

Na K C1 HCO3

a. 140 5 104 30

b. 140 5 75 115

c. 60 10 130 0

d. 10 26 10 30

e. 60 30 40 50

44. Salivary (SELECT 1 COMPOSITION)

45. Stomach (SELECT 1 COMPOSITION)

46. Small bowel (SELECT 1 COMPOSITION)

Items 47-50

A 42-year-old man has a calculated resting energy expenditure of 1800

kcal/day (basal energy expenditure plus 10%). Match the following clinical

situations with the appropriate daily energy requirement.

a. 1600

b. 2300

c. 2800

d. 3600

e. 4500

14 Surgery

47. Sepsis (SELECT 1 EXPENDITURE)

48. Skeletal trauma (SELECT 1

EXPENDITURE)

49. Third-degree burns of 60% of

body surface area (BSA) (SELECT

1 EXPENDITURE)

50. Prolonged starvation (SELECT

1 EXPENDITURE)

Pre- and Postoperative Care 15

PRE- AND POSTOPERATIVE

CARE

Answers

1. The answer is a. (Schwartz, 7/e, pp 65-66.) States of magnesium

excess are characterized by generalized neuromuscular depression. Clinically,

severe hypermagnesemia is rarely seen except in those patients with

advanced renal failure treated with magnesium-containing antacids.

Hypermagnesemia is produced intentionally, however, by obstetricians

who use parenteral magnesium sulfate (MgSO4) to treat preeclampsia.

MgSO4 is administered until depression of the deep tendon reflexes is

observed, a deficit that occurs with modest hypermagnesemia (over 4

meq/L). Greater elevations of magnesium produce progressive weakness,

which culminates in flaccid quadriplegia and in some cases respiratory

arrest from paralysis of the chest bellows mechanism. Hypotension may

occur because of the direct arteriolar relaxing effect of magnesium.

Changes in mental status occur in the late stages of the syndrome and are

characterized by somnolence that progresses to coma.

2. The answer is b. (Schwartz, 7/e, pp 57-63.) Acute severe hyponatremia

sometimes occurs following elective surgical procedures. It is usually

the result of the combination of appropriate postoperative stimulation

of antidiuretic hormone and injudicious administration of excess free

water in the first few postoperative days. Totally sodium-free intravenous

fluids (e.g., dextrose and water) should be given with great caution postoperatively,

since occasionally the resulting hyponatremia can be associated

with sudden death from a flaccid heart or with severe permanent

brain damage. The condition is usually best treated by withholding free

water and allowing the patient to reequilibrate spontaneously. At levels

below 115 meq/L, seizures or mental obtundation may mandate treatment

with hypertonic sodium solutions. This must be done with extreme care

because the risk of fluid overload with acute pulmonary or cerebral edema

is high.

16

3. The answer is d. (Sabiston, 15/e, p 931.) Any patient who has lost

much of the ileum (whether from injury, disease, or elective surgery) is at

high risk of developing enteric hyperoxaluria if the colon remains intact.

Calcium oxalate stones will develop in at least 10% of these patients. The

condition results from excessive absorption of oxalate from the colon

through two related synergistic mechanisms: unabsorbed fatty acids combine

with calcium, which prevents the formation of insoluble calcium

oxalate and allows oxalate to remain available for colonic absorption; and

unabsorbed fatty acids and bile acids also increase the permeability of the

colon to the oxalate.

4. The answer is c. (Schwartz, 7/e, pp 452-455.) When oliguria occurs

postoperatively, it is important to differentiate between low output caused

by the physiologic response to intravascular hypovolemia and that caused

by acute tubular necrosis. The fractional excretion of sodium (FENa) is an

especially useful test to aid in this differentiation. Values of FE < 1% in an

oliguric setting indicate aggressive sodium reclamation in the tubules; values

above this suggest tubular injury. The fractional excretion is a simple

calculation: (urine Na × serum creatinine) ÷ (serum sodium × urinary creatinine).

In the setting of postoperative hypovolemia, all findings would

reflect the kidney's efforts to retain volume: the urine sodium would be

below 20 meq/L, the urine chloride would not be helpful except in the

metabolically alkalotic patient, the serum osmolality would be over 500

mOsm/kg, and the urine/serum creatinine ratio would be above 40.

5. The answer is c. (Schwartz, 7/e, pp 64-66.) Magnesium deficiency is

common in malnourished patients and patients with large gastrointestinal

fluid losses. The neuromuscular effects resemble those of calcium deficiency-

namely, paresthesia, hyperreflexia, muscle spasm, and ultimately

tetany. The cardiac effects are more like those of hypercalcemia. An electrocardiogram

therefore provides a rapid means of differentiating between

hypocalcemia and hypomagnesemia. Hypomagnesemia also causes potassium

wasting by the kidney. Many hospital patients with refractory hypocalcemia

will be found to be magnesium deficient. Often this deficiency

becomes manifest during the response to parenteral nutrition when normal

cellular ionic gradients are restored. A normal blood pH and arterial PCO2

rule out hyperventilation. The serum calcium in this patient is normal when

Pre- and Postoperative Care Answers 17

adjusted for the low albumin. Hypomagnesemia causes functional hypoparathyroidism,

which can lower serum calcium and thus result in a combined

defect.

6. The answer is c. (Schwartz, 7/e, pp 143-149.) Many clinical and experimental

studies have looked at the optimum bowel preparation and preoperative

regimen for elective colonic surgery to reduce the postoperative

infectious complications of wound infection, intraabdominal abscess, and

anastomotic leakage. Currently, a postoperative rate of wound infection of

only 5% can be attained by combining mechanical cleansing, oral antibiotics,

and perioperative parenteral antibiotics. The type of mechanical cleansing

does not matter as long as it is effective. Preoperative oral antibiotics may be

administered one or more days prior to surgery and should cover aerobes

and anaerobes (e.g., neomycin-erythromycin). Parenteral antibiotics effective

against aerobes and anaerobes (e.g., cefoxitin) should be administered on call

to the operating room as a single dose and no more than 24 h postoperatively.

Both antibiotic regimens yield maximum prophylaxis without fostering resistant

transformation of microbes. Procedures that require operative time

greater than 3 h or that involve the extraperitoneal rectum are associated with

an increased risk of infectious complications.

7. The answer is c. (Schwartz, 7/e, pp 462-465.) There are several recommended

interventions in cardiac patients who are undergoing noncardiac

surgery. The two factors that correlate best with postoperative lifethreatening

or fatal cardiac complications are myocardial infarction (transmural

or subendocardial) and uncontrolled congestive heart failure.

Hence, delay of elective surgery for 6 mo after myocardial infarction and

preoperative control of congestive heart failure with diuretics and digitalis,

in severe cases, will have the greatest effect in decreasing the risks of

surgery. A patient's cardiac medications should be continued preoperatively,

including during the morning of surgery, to maintain adequate therapeutic

levels. This is especially true for beta blockers, which can manifest

withdrawal rebound hypertension and tachycardia approximately 24 h

after discontinuation. Patients with prosthetic valves or valvular heart disease

should be given prophylactic antibiotics to prevent seeding of their

valves during episodes of significant bacteremia. This most commonly

occurs during gastrointestinal or genitourinary procedures. Ampicillin and

18 Surgery

gentamicin cover the flora frequently encountered, including enterococci

and gram-negative organisms.

8. The answer is d. (Greenfield, 2/e, pp 259-266.) Both the arterial pH

and the PCO2 are elevated in the patient presented in the question; the disturbance

is alkalosis with hypoventilation. The PCO2 typically increases by

0.5-1.0 pKa for each meq/L increase in serum bicarbonate. These findings

suggest that the hypoventilation is compensatory rather than a primary

phenomenon. This assumption is further supported by the absence of clinical

lung disease.

9. The answer is a. (Greenfield, 2/e, pp 259-266.) The development of a

clinically significant metabolic alkalosis in a patient requires not only the

loss of acid or addition of alkali, but renal responses that maintain the alkalosis.

The normal kidney can tremendously augment its excretion of acid or

alkali in response to changes in ingested load. However, in the presence of

significant volume depletion and consequent excessive salt and water

retention, the tubular maximum for bicarbonate reabsorption is increased.

Correction of volume depletion alone is usually sufficient to correct the

alkalosis, since the kidney will then excrete the excess bicarbonate. HCl

infusion is usually unnecessary and can be dangerous. Acetazolamide is

unlikely to be effective in the face of distal Na+ reabsorption (in exchange

for H+ secretion). Moreover, to the extent that acetazolamide causes natriuresis,

it will exacerbate the volume depletion.

10. The answer is d. (Greenfield, 2/e, pp 260-266.) The patient presented

in the question is in a state of metabolic acidosis as shown by a markedly

increased anion gap of 28 meq unmeasured anions per liter of plasma.

However, the respiratory response is greater than can be explained by a

compensatory response, since the patient is mildly alkalemic. The disturbance

cannot be pure respiratory alkalosis, since the serum bicarbonate

does not drop below 15 meq/L as a result of renal compensation and the

anion gap does not vary by more than 1-2 meq/L from its normal value of

12 in response to a respiratory disturbance. The renal response to hyperventilation

involves wasting of bicarbonate and compensatory retention of

chloride; it does not involve a change in the concentration of "unmeasured"

anions, such as albumin and organic acids.

Pre- and Postoperative Care Answers 19

11. The answer is b. (Anderson, Ann Intern Med 85:745-748, 1976.) The

acid-base disturbance in the patient described in the previous question

demonstrates the value of extracting all available information from a small

amount of rapidly retrievable data, e.g., arterial blood gases. Salicylates

directly stimulate the respiratory center and produce respiratory alkalosis.

By building up an accumulation of organic acids, salicylates also produce a

concomitant metabolic acidosis. Characteristically both disturbances exist

simultaneously following massive ingestion of salicylates. If sedative agents

have been taken as well, the respiratory alkalosis (and even the respiratory

compensation) may be absent. Phenformin and methanol overdoses also

produce "high-anion-gap" metabolic acidosis, but without the simultaneous

respiratory disturbance. In the case presented, the patient's history of

tinnitus in conjunction with her mixed metabolic acidosis-respiratory

alkalosis is essentially pathognomonic of salicylate intoxication.

12. The answer is c. (Sabiston, 15/e, pp 131-133.) Whenever significant

bleeding is noted in the early postoperative period, the presumption

should always be that it is due to an error in surgical control of blood vessels

in the operative field. Hematologic disorders that are not apparent during

the long operation are most unlikely to surface as problems

postoperatively. Blood transfusion reactions can cause diffuse loss of clot

integrity; the sudden appearance of diffuse bleeding during an operation

may be the only evidence of an intraoperative transfusion reaction. In the

postoperative period, transfusion reactions usually present as unexplained

fever, apprehension, and headache-all symptoms difficult to interpret in

the early postoperative period. Factor VIII deficiency (hemophilia) would

almost certainly be known by history in a 65-year-old man, but if not,

intraoperative bleeding would have been a problem earlier in this long

operation. Severely hypothermic patients will not be able to form clots

effectively, but clot dissolution does not occur. Care should be taken to prevent

the development of hypothermia during long operations through the

use of warmed intravenous fluid, gas humidifiers, and insulated skin barriers.

13. The answer is c. (Goldman, J Cardiothorac Anesth 1:237, 1987.) The

work of Goldman and others has served to identify risk factors for perioperative

myocardial infarction. The highest likelihood is associated with

recent myocardial infarction: the more recent the event, the higher the risk

20 Surgery

up to 6 mo. It should be noted, however, that the risk never returns to normal.

A non-Q-wave infarction may not have destroyed much myocardium,

but it leaves the surrounding area with borderline perfusion; hence the particularly

high risk of subsequent perioperative infarction. Evidence of congestive

heart failure, such as jugular venous distention, or S3 gallop also

carries a high risk, as does the frequent occurrence of ectopic beats. Old

age and emergency surgery are risk factors independent of these others.

Coronary revascularization by coronary artery bypass graft (CABG) tends

to protect against myocardial infarction. Smoking, diabetes, hypertension,

and hyperlipidemia (all of which predispose to coronary artery disease) are

surprisingly not independent risk factors, although they may increase the

death rate should an infarct occur. The value of this information and data

derived from further testing is that it identifies the patient who needs to be

monitored invasively with a systemic arterial catheter and pulmonary arterial

catheter. Most perioperative infarcts occur postoperatively when the

"third-space" fluids return to the circulation, which increases the preload

and the myocardial oxygen consumption. This generally occurs around the

third postoperative day.

14. The answer is c. (Schwartz, 7/e, pp 966-967.) Acute mesenteric

ischemia may be difficult to diagnose. The condition should be suspected in

patients with either systemic manifestations of arteriosclerotic vascular disease

or low cardiac output states associated with a sudden development of

abdominal pain that is out of proportion to the physical findings. Lactic acidosis

and an elevated hematocrit reflecting hemoconcentration are common

laboratory findings. Abdominal films show a nonspecific ileus pattern. The

cause may be embolic occlusion or thrombosis of the superior mesenteric

artery, primary mesenteric venous occlusion, or nonocclusive mesenteric

ischemia secondary to low cardiac output states. A mortality of 65-100% is

reported. The majority of affected patients are at high operative risk, but

since early diagnosis followed by revascularization or resectional surgery or

both is the only hope for survival, celiotomy must be performed once the

diagnosis of arterial occlusion or bowel infarction has been made. Initial

treatment of nonocclusive mesenteric ischemia includes measures to

increase cardiac output and blood pressure and the direct intraarterial infusion

of vasodilators such as papaverine into the superior mesenteric system.

The patient presented in the question is at risk for both occlusive and

nonocclusive mesenteric ischemic disease. If his clinical status permits,

Pre- and Postoperative Care Answers 21

angiographic studies should be performed before the operation to establish

the diagnosis and to determine whether embolectomy, revascularization, or

nonsurgical management is indicated as initial treatment.

15. The answer is b. (Schwartz, 7/e, pp 1007-1014.) This patient has a

left iliofemoral vein thrombosis, as evidenced by sudden massive swelling

of her entire left lower extremity. Noninvasive venous testing should be

quite helpful as the venous obstruction extends above the knee; therefore,

venography and x-ray exposure are unnecessary. Heparin is the preferred

agent because it does not cross the placenta, while warfarin does. The vena

caval filter is not indicated because there is no contraindication to heparin

therapy and there has not been any evidence of pulmonary embolus.

16. The answer is e. (Sabiston, 15/e, pp 134-135.) von Willebrand disease

has an autosomal dominant pattern of inheritance that affects both

men and women. The deficiency of factor VIII activity is generally less

severe than in classic hemophilia and tends to fluctuate even in an

untreated patient. However, the bleeding tendency is compounded by

abnormal platelet function. This is responsible for the common occurrence

of epistaxis and menorrhagia. In 70% of patients, platelets fail to aggregate

in response to the diagnostic reagent ristocetin. Transfusion of cryoprecipitate

provides factor VIII R:WF (the von Willebrand factor), whereas infusions

of high-purity concentrates of factor VIII:C are not effective. These

patients do not generally require treatment unless they need surgery or are

severely injured; therefore, they have not usually received the contaminated

concentrates responsible for the 80% prevalence of HIV seropositivity

among hemophiliacs.

17. The answer is b. (Schwartz, 7/e, pp 85-87.) Intraoperative and postoperative

hemorrhage is a significant problem in the patient with polycythemia

vera. Despite thrombocytosis, these patients have a hemorrhagic

tendency generally ascribed to a qualitative deficiency of the platelets. Elective

surgery should be postponed until the hematocrit and platelet count

reach normal levels. Alkylating agents, such as busulfan or chlorambucil,

are effective in this regard. In the emergency situation, phlebectomy should

be performed prior to operation and also an especially careful hemostatic

technique should be employed. Infection is also a problem in patients with

22 Surgery

polycythemia vera, but hemorrhagic problems are the more frequently

encountered complications.

18. The answer is c. (Schwartz, 7/e, p 96.) When large amounts of banked

blood are transfused, the recipient becomes deficient in factors V and VIII

(the "labile" factors) and an acquired coagulopathy ensues. Since banked

blood is also deficient in platelets, thrombocytopenia may also develop.

19. The answer is b. (Schwartz, 7/e, p 467.) The misconception that the

entire bowel does not function in the early postoperative period is still

widely held. Intestinal motility and absorption studies have clarified the

patterns by which bowel activity resumes. The stomach remains uncoordinated

in its muscular activity and does not empty efficiently for about 24 h

after abdominal procedures. The small bowel functions normally within

hours of surgery and is able to accept nutrients promptly, either by nasoduodenal

or percutaneous jejunal feeding catheters or, after 24 h, by gastric

emptying. The colon is stimulated in large measure by the gastrocolic

reflex but ordinarily is relatively inactive for 3-4 days.

20. The answer is a. (Greenfield, 2/e, pp 96-97.) In a heparinized patient

with significant life-threatening hemorrhage, immediate reversal of heparin

anticoagulation is indicated. Protamine sulfate is a specific antidote to

heparin and should be given as 1 mg for each 100 U heparin if hemorrhage

begins shortly after a bolus of heparin. For a patient (such as this) in whom

heparin therapy is ongoing, the dose should be based on the half-life of

heparin (90 min). Since protamine is also an anticoagulant, only half the

calculated circulating heparin should be reversed. The protaminization

should be followed by placement of a percutaneous vena cava filter (Greenfield

filter). In this critically ill patient, exploration of the retroperitoneal

space would be surgically challenging and meddlesome.

21. The answer is d. (Diettrich, Arch Surg 126:860-865, 1991.) Patients

who have AIDS frequently present with problems that potentially require

surgical care. The involvement of surgeons with these patients will increase

as more effective treatments are developed and the AIDS patient's survival

is prolonged. AIDS patients not only suffer from common surgical illnesses,

they also develop problems especially associated with their altered immune

Pre- and Postoperative Care Answers 23

status, such as bleeding from gastrointestinal lymphomas or Kaposi's

lesions, bowel ischemia, perforation from parasitic or viral infection, acalculous

cholecystitis, and retroperitoneal and intraabdominal masses due to

massive lymphadenitis. With the exception of tracheostomy, experience

has demonstrated that surgery can be performed with acceptable morbidity

and mortality and that it seems to provide comfort and prolong quality

life. Though it may facilitate nursing care, tracheostomy does not reverse or

slow the pulmonary failure once the patient has become ventilator dependent.

22. The answer is c. (Schwartz, 7/e, pp 1639-1640.) Acute adrenal insufficiency

is classically manifested as changing mental status, increased temperature,

cardiovascular collapse, hypoglycemia, and hyperkalemia. The

diagnosis can be difficult to make and requires a high index of suspicion. Its

clinical presentation is similar to that of sepsis; however, sepsis is generally

associated with hyperglycemia and no significant change in potassium. The

treatment for adrenal crisis is hydrocortisone 100 mg intravenously, volume

resuscitation, and other supportive measures to treat any new or ongoing

stress. Then, 200-400 hydrocortisone mg is administered over the next 24

h, followed by a taper of the steroid as tolerated.

23. The answer is c. (Schwartz, 7/e, pp 95-96.) Transfusions with fresh

frozen plasma (FFP) are given to replenish clotting factors. The effectiveness

of the transfusion in maintaining hemostasis is dependent on the

quantity of each factor delivered and its half-life. The half-life of the most

stable clotting factor, factor VII, is 4-6 h. A reasonable transfusion scheme

would be to give FFP on call to the operating room. This way the transfusion

is complete prior to the incision with circulating factors to cover the

operative and immediate postoperative period.

24. The answer is c. (Sabiston, 15/e, pp 344-345.) Serosanguineous

drainage is classically associated with fascial dehiscence. A reasonable

approach to this problem is to remove several sutures and gently explore

the wound to determine the extent of the dehiscence. A small fascial dehiscence

(1-2 cm) can be treated conservatively with local wound care and an

abdominal binder to support the fascia. A larger dehiscence requires reoperation

for formal reclosure of the fascia. High-risk patients with a large fascial

dehiscence may be treated with an abdominal binder and modified bed

24 Surgery

rest, which allows both intraabdominal adhesion formation and local granulation.

Although fascial dehiscence can occur from local infection, it is

usually not an infectious process and does not require parenteral antibiotic

therapy.

25. The answer is d. (Sabiston, 15/e, pp 344-345.) The appearance of a

gush of serosanguineous fluid from an abdominal incision is pathognomonic

of a disruption of the deep fascia. The source of large amounts of

serous fluid is the peritoneum. The temptation to avoid direct reclosure of

these wounds when the fascial defect is larger than 1-2 cm should be

resisted because delayed resumption of normal ambulation and activity

with a late ventral hernia is the best outcome to be hoped for. Evisceration,

wound infection, or protracted convalescence is far more likely. Recurrence

of eviscerations following reclosure of these wounds is extremely rare,

though 10-20% will later develop incisional hernias. The Scultetus binder

is a corsetlike cloth wrap that was once a favored support to reduce likelihood

of evisceration in those wounds in which the fascia was left unrepaired

after dehiscence.

26. The answer is d. (Sabiston, 15/e, p 124.) Allergic and febrile reactions

occur in about 1% of all transfusions. Hemolytic transfusion reactions are

much less common (0.2%) with fatal reactions in 1:100,000 transfusions.

Hemolytic transfusion reactions are due to the reaction of recipient antibodies

against transfused antigens. These reactions can be both immediate

and delayed. Symptoms of a hemolytic transfusion reaction include fever,

chills, and pain and heat at the infusion site, as well as respiratory distress,

anxiety, hypotension, and oliguria. During surgery a hemolytic transfusion

reaction can manifest as abnormal bleeding.

27. The answer is e. (Sabiston, 15/e, p 124.) Hemolytic transfusion reactions

lead to hypotension and oliguria. The increased hemoglobin in the

plasma will be cleared via the kidneys, which leads to hemoglobinuria.

Placement of an indwelling Foley catheter with subsequent demonstration

of oliguria and hemoglobinuria not only confirms the diagnosis of a

hemolytic transfusion reaction but is useful in monitoring corrective therapy.

Treatment begins with discontinuation of the transfusion, followed by

aggressive fluid resuscitation to support the hypotensive episode and

increase urine output. Inducing a diuresis through aggressive fluid resusci-

Pre- and Postoperative Care Answers 25

tation and osmotic diuretics is important to clear the hemolyzed red cell

membranes, which can otherwise collect in glomeruli and cause renal

damage. Alkalinization of the urine (pH > 7) helps prevent hemoglobin

clumping and renal damage. Steroids do not have a role in the treatment of

hemolytic transfusion reactions.

28. The answer is d. (Sabiston, 15/e, p 133.) Platelet dysfunction, measured

by bleeding time, has been associated with a long list of drugs.

Among nonsteroidal anti-inflammatory and analgesic medications, aspirin,

indomethacin, phenylbutazone, acetominophen, and phenacetin have

been implicated, along with aminopyrine and codeine. Ibuprofen, however,

has not. In addition, many antibiotics, anticonvulsants, and sedatives

have been associated with thrombasthenia. Any time platelet abnormalities

are suspected, a careful review of the drugs the patient is receiving should

be undertaken, and a measurement should be made of the platelet count

and bleeding time. Platelet dysfunction does not affect APTT, PT, reptilase,

or thrombin times.

29. The answer is d. (Sabiston, 15/e, pp 60-62.) The metabolic response

to surgery (and other trauma) is a result of neuroendocrine stimulation that

sharply accelerates protein breakdown, stimulates gluconeogenesis, and

produces glucose intolerance. The glycogen stores are rapidly depleted

because of a fall in insulin and a rise in glucagon levels in the plasma. The

peripheral effects of the neuroendocrine secretion result in an increase in

plasma levels of amino acids, free fatty acids, lactate, glucose, and glycerol.

In the liver, the cortisol and glucagon stimulate glycogenolysis, gluconeogenesis,

and increased substrate uptake.

30. The answer is a. (Berci, Am J Surg 161:332-335, 1991.) The indications

for diagnostic laparoscopic exploration are increasing rapidly as the

tools and techniques for such intervention improve. In the stable trauma

patient with a tangential gunshot wound or with a stab wound to the lower

chest wall or abdomen, laparoscopy may show no actual peritoneal penetration

and might make a laparotomy unnecessary. If the peritoneum or

diaphragm is injured, subsequent laparotomy and exploration are generally

indicated to exclude other possible injuries and to facilitate repair of

the diaphragm. All unstable patients or those with signs of peritoneal irritation

(e.g., rebound tenderness) should undergo prompt celiotomy.

26 Surgery

Laparoscopic staging of malignancies allows improved preoperative assessment

of the resectability of intraabdominal malignancies. The procedure

has proved particularly useful in cases with pancreatic carcinoma. Laparoscopic

evaluations may expedite differentiation of competing etiologies of

right lower quadrant pain; this would allow appendectomy for appendicitis

or appropriate therapy such as intravenous antibiotics for pelvic inflammatory

disease and preempt celiotomy. In critically ill patients, the

development of low flow or embolic ischemic insults to the bowel can be

fatal if not recognized and treated early. Many such patients are already

being ventilated in intensive care units; in this setting, bedside laparoscopy

can ascertain the need for early exploration for bowel revascularization or

resection.

31. The answer is d. (Schwartz, 7/e, p 1693.) Postthyroidectomy

hypocalcemia is usually due to transient ischemia of the parathyroid glands

and is self-limited. When it becomes symptomatic, it should be treated

with intravenous infusions of calcium. In most cases the problem is

resolved in several days. If hypocalcemia persists, oral therapy is then

added with calcium gluconate. Vitamin D preparations are only used if

hypocalcemia is prolonged and permanent hypocalcemia is suspected.

There is no role for thyroid hormone replacement or magnesium sulfate in

the treatment of hypocalcemia.

32. The answer is c. (Schwartz, 7/e, p 64.) Hypocalcemia is associated

with a prolonged QT interval and may be aggravated by both hypomagnesemia

and alkalosis. Serum calcium levels below 7.0 mg/dL, encountered

most frequently following parathyroid or thyroid surgery or in patients

with acute pancreatitis, should be treated with intravenous calcium gluconate

or lactate. The myocardium is very sensitive to calcium levels; therefore

calcium is considered a positive inotropic agent. Calcium increases the

contractile strength of cardiac muscle as well as the velocity of shortening.

In its absence the efficiency of the myocardium decreases. Hypocalcemia

often occurs with hypoproteinemia even though the ionized serum calcium

fraction remains normal.

33. The answer is b. (Schwartz, 7/e, p 56.) Bile and the fluids found in

the duodenum, jejunum, and ileum all have an electrolyte content similar

to that of Ringer's lactate. Saliva, gastric juice, and right colon fluids have

Pre- and Postoperative Care Answers 27

high K+ and low Na+ content. Pancreatic secretions are high in bicarbonate.

It is important to consider these variations in electrolyte patterns when calculating

replacement requirements following gastrointestinal losses.

34. The answer is d. (Schwartz, 7/e, p 63.) Reduction of an elevated

serum potassium level is important to avoid the cardiovascular complications

that ultimately culminate in diastolic cardiac arrest. Kayexalate is a

cation exchange resin that is instilled into the gastrointestinal tract and

exchanges sodium for potassium ions. Its use is limited to semiacute and

chronic potassium elevations. Sodium bicarbonate causes a rise in serum

pH and shifts potassium intracellularly. Administration of glucose initiates

glycogen synthesis and uptake of potassium. Insulin can be used in conjunction

with this to aid in the shift of potassium intracellularly. Calcium

gluconate does not affect the serum potassium level but rather counteracts

the myocardial effects of hyperkalemia.

35-37. The answers are 35-a, 36-d, 37-b. (Schwartz, 7/e, pp 448-452.)

The determinants of a postoperative wound infection include those related

to the bacteria, the environment (i.e., the wound), and the host's defense

mechanisms. Within this triad there are factors predetermined by the status

of the patient [e.g., age, obesity, steroid dependence, multiple diagnoses

(more than three), immunosuppression] and by the type of procedure

(e.g., contaminated versus clean, emergent versus elective). However, there

are several factors that can be optimized by the surgeon. Decreasing the

bacterial inoculum and virulence by limiting the patient's prehospital stay,

clipping the operative site in the operating room, administering perioperative

antibiotics (within a 24-h period surrounding operation) with an

appropriate antimicrobial spectrum, treating remote infections, avoiding

breaks in technique, using closed drainage systems (if needed at all) that

exit the skin away from the surgical incision, and minimizing the duration

of the operation have all been shown to decrease postoperative infection.

Making a wound less favorable to infection requires attention to basic halstedian

principles of hemostasis, anatomic dissection, and gentle handling

of tissues as well as limiting the amount of foreign body and necrotic tissue

in the wound. Although they are the most difficult factors to influence, host

defense mechanisms can be improved by optimizing nutritional status, tissue

perfusion, and oxygen delivery.

28 Surgery

38-39. The answers are 38-e, 39-d. (Schwartz, 7/e, pp 66-67.) Isotonic

saline solutions contain 154 meq/L of both sodium and chloride ions. Each

ion is in a substantially higher concentration than is found in the normal

serum (Na = 142 meq/L; C1 = 103 meq/L). When isotonic solutions are

given in large quantities, they overload the kidney's ability to excrete chloride

ion, which results in a dilutional acidosis. They also may intensify preexisting

acidosis by reducing the base bicarbonate:carbonic acid ratio in

the body. Isotonic saline solutions are particularly useful in hyponatremic

or hypochloremic states and whenever a tendency to metabolic alkalosis is

present, as occurs with significant nasogastric suction losses or vomiting.

Administration of lactated Ringer's solution is appropriate for replacing

gastrointestinal losses and correcting extracellular fluid deficits. Containing

130 meq/L sodium, lactated Ringer's is hyposmolar with respect to

sodium and provides approximately 150 mL of free water with each liter

given. Although this is ordinarily not a significant load, in some clinical situations

it can be. Lactated Ringer's is sufficiently "physiological" to enable

administration of large amounts without significantly affecting the body's

acid-base balance. It is worth noting that both isotonic saline and lactated

Ringer's are acidic with respect to the plasma: 0.9% NaC1/5% dextrose has

a pH of 4.5; lactated Ringer's has a pH of 6.5.

40. The answer is b. (Schwartz, 7/e, pp 473-474.) The patient presented

has the syndrome of inappropriate antidiuretic hormone secretion (SIADH).

Although this syndrome is primarily associated with diseases of the central

nervous system or of the chest (e.g., oat cell carcinoma of the lung), excessive

amounts of antidiuretic hormone are also present in most postoperative

patients. The pathophysiology of SIADH involves an inability to dilute the

urine; administered water is therefore retained, which produces dilutional

hyponatremia. Body sodium stores and fluid balance are normal, as evidenced

by the absence of the clinical findings suggestive of abnormalities of

extracellular fluid volume. While hypertonic saline infusions can transiently

improve hyponatremia, the appropriate therapy is to restrict water ingestion

to a level below the patient's ability to excrete water. Hypertonic saline may

be dangerous, since it can shift accumulated water into the extracellular

fluid and precipitate pulmonary edema in the patient who suffers from low

cardiac reserves. Hyperglycemia cannot account for the hyponatremia seen

in this patient because the serum osmolality, as well as the serum sodium, is

Pre- and Postoperative Care Answers 29

depressed. Hyponatremia resulting from hyperglycemia would be associated

with an elevated serum osmolality.

41. The answer is a. (Schwartz, 7/e, p 63.) The electrocardiogram exhibited

in the question demonstrates changes that are essentially diagnostic of

severe hyperkalemia. Correct treatment for the affected patient includes

administration of a source of calcium ions (which will immediately oppose

the neuromuscular effect of potassium) and administration of sodium ions

(which, by producing a mild alkalosis, will shift potassium into cells); each

will temporarily reduce serum potassium concentration. Infusion of glucose

and insulin would also effect a temporary transcellular shift of potassium.

However, these maneuvers are only temporarily effective; definitive

treatment calls for removal of potassium from the body. The sodiumpotassium

exchange resin sodium polystyrene sulfonate (Kayexalate)

would accomplish this removal, but over a period of hours and at the price

of adding a sodium ion for each potassium ion that is removed. Hemodialysis

or peritoneal dialysis is probably required for this patient, since these

procedures also rectify the other consequences of acute renal failure, but

they would not be the first line of therapy given the acute need to reduce

the potassium level. Both lidocaine and digoxin would not only be ineffective

but contraindicated, since they would further depress the myocardial

conduction system.

42. The answer is b. (Sabiston 15/e, pp 1594-1616.) The problem of deep

vein thrombosis and pulmonary embolism is significant in general surgery.

There are approximately 2.5 million episodes of deep vein thrombosis and

600,000 pulmonary embolic events that result in 200,000 deaths annually.

The problem is exacerbated by the disorder's frequent unheralded progression-

only 20-25% of fatal pulmonary emboli are suspected clinically by

the physician or manifest by classic signs or symptoms. The fact that most

deaths due to pulmonary embolism occur before effective therapy can be

started highlights the importance of preventive measures. Several documented

factors help identify those at increased risk, including age greater

than 40, obesity, malignancy, venous disease, congestive heart failure and

atrial fibrillation, and prolonged bed rest. Virchow initially attributed

venous thrombosis to the combination of venous stasis, hypercoagulability,

and endothelial injury. The first two conditions are exacerbated by operative

positioning and stress such that 25% of patients at moderate risk will

30 Surgery

develop venous thromboembolism, 50% within 24 h and 80% within 72 h

postoperatively. The recommendation for prophylaxis in those at high risk

is preoperative anticoagulation with warfarin. No prophylaxis is recommended

for those at low risk (e.g., those less than age 40 with normal

weight and no venous disease). Prophylactic regimens for those at moderate

risk are basically chemical or mechanical, and the best two, which have

equivalent effectiveness, are representative of each type. First, low-dose

heparin (5000 U) started 2 h preoperatively and continued every 12 h

postoperatively will decrease the risk of deep vein thrombosis from 25 to

7% and of major pulmonary embolus from 6 to 0.6%. External pneumatic

compression devices not only obviate venous stasis, but they also have a

systemic effect on coagulation, such that use on the arms also significantly

reduces venous thromboembolism of the lower extremities. Early ambulation,

elastic stockings, leg elevation, and dipyridamole (Persantine) alone

have not been documented to be effective.

43. The answer is e. (Schwartz, 7/e, pp 115-120.) It is important to identify

and treat occult or early sepsis before it progresses to septic shock and

the associated complications of multiple organ failure. An immunocompromised

host may not manifest some of the more typical signs and symptoms

of infection, such as elevated temperature and white cell count; this

forces the clinician to focus on more subtle signs and symptoms. Early sepsis

is a physiologically hyperdynamic, hypermetabolic state representing a

surge of catecholamines, cortisol, and other stress-related hormones. A

changing mental status, tachypnea that leads to respiratory alkalosis, and

flushed skin are often the earliest manifestations of sepsis. Intermittent

hypotension requiring increased fluid resuscitation to maintain adequate

urine output is characteristic of occult sepsis. Hyperglycemia and insulin

resistance during sepsis are typical in diabetic as well as nondiabetic

patients. This relates to the gluconeogenic state of the stress response. The

cardiovascular response to early sepsis is characterized by an increased cardiac

output, decreased systemic vascular resistance, and decreased peripheral

utilization of oxygen, which yields a decreased arteriovenous oxygen

difference.

44-46. The answers are 44-d, 45-c, 46-a. (Schwartz, 7/e, p 56.) One of

the most common causes of dehydration and metabolic disarray in surgical

patients is the failure to replace gastrointestinal losses. External losses can

Pre- and Postoperative Care Answers 31

often be collected for measurement of volume and ionic composition.

Accurate replacement of these measured losses is clearly the best method of

avoiding imbalance. However, a knowledge of the ionic composition of the

intestinal contents at various sites permits an accurate estimate for early

replacement. Most of these secretions start as extracellular fluid (with a

composition similar to that of plasma) and are modified by intestinal

glands. The stomach substitutes hydrogen ions for sodium and thus eliminates

all but a tiny fraction of bicarbonate. The glands of the small intestine

secrete various amounts of bicarbonate; the chloride content is depressed

to an equivalent degree (to maintain ionic balance). Colonic contents

(stool) and saliva are most notable for their potassium content. Stool also

has a high bicarbonate content. Severe diarrhea can therefore cause potassium

depletion and a metabolic acidosis.

47-50. The answers are 47-c, 48-b, 49-d, 50-a. (Schwartz, 7/e, pp

33-40.) Resting energy expenditure in the nonstressed patient is approximately

10% greater than basal energy expenditure. The resting energy

expenditure increases directly proportional to the degree of stress. Studies

by Kinney and associates using indirect calorimetry have documented the

relative degree of increase in resting energy expenditure for a variety of

clinical situations. The following table summarizes these results:

32 Surgery

Change in Energy

Clinical Situation Expenditure

Prolonged starvation Decreased 10-30%

Skeletal trauma Increased 10-30%

Sepsis Increased 30-60%

Third-degree burns 20% BSA Increased 50-100%

CRITICAL CARE:

ANESTHESIOLOGY, BLOOD

GASES, RESPIRATORY CARE

Questions

DIRECTIONS: Each item below contains a question or incomplete

statement followed by suggested responses. Select the one best response to

each question.

33

51. The most common physiologic

cause of hypoxemia is

a. Hypoventilation

b. Incomplete alveolar oxygen diffusion

c. Ventilation-perfusion inequality

d. Pulmonary shunt flow

e. Elevated erythrocyte 2,3-diphosphoglycerate

level (2,3-DPT)

52. Generally accepted indications

for mechanical ventilatory support

include

a. PaO2 of less than 70 kPa and PaCO2 of

greater than 50 kPa while breathing

room air

b. Alveolar-arterial oxygen tension

difference of 150 kPa while breathing

100% O2

c. Vital capacity of 40-60 mL/kg

d. Respiratory rate greater than 35

breaths/min

e. A dead space:tidal volume ratio

(VD/VT) less than 0.6

53. In a hemolytic reaction caused

by an incompatible blood transfusion,

the treatment that is most

likely to be helpful is

a. Promoting a diuresis with 250 ml

of 50% mannitol

b. Treating anuria with fluid and

potassium replacement

c. Acidifying the urine to prevent

hemoglobin precipitation in the

renal tubules

d. Removing foreign bodies, such as

Foley catheters, which may cause

hemorrhagic complications

e. Stopping the transfusion immediately

54. Which of the following inhalation

anesthetics accumulates in

air-filled cavities during general

anesthesia?

a. Diethyl ether

b. Nitrous oxide

c. Halothane

d. Methoxyflurane

e. Trichloroethylene

Terms of Use

55. Major alterations in pulmonary

function associated with

adult respiratory distress syndrome

(ARDS) include

a. Hypoxemia

b. Increased pulmonary compliance

c. Increased resting lung volume

d. Increased functional residual

capacity

e. Decreased dead space ventilation

56. The curve depicted below

plots the normal relationship of

arterial PO2 and percentage of

hemoglobin saturation with other

variables controlled at pH 7.4,

PaCO2 40 kPa, temperature 37°C

(98.6°F), and hemoglobin 15 g/dL.

Which of the following statements

regarding this oxygen dissociation

relationship is true?

34 Surgery

50 100

PO2 torr

% Hb Saturation

100

50

a. Modest decrements of arterial PO2

have a major effect on alveolar oxygen

uptake

b. Modest decrements of hemoglobin

saturation have a major effect on

tissue oxygen uptake

c. The curve shifts to the left with acidosis

d. The curve shifts to the left following

banked blood transfusion

e. The curve is unaffected by chronic

lung disease

57. A 64-year-old man afflicted

with severe emphysema, who receives

oxygen therapy at home, is

admitted to the hospital because of

upper gastrointestinal bleeding.

The bleeding ceases soon after

admission, and the patient

becomes agitated and then disoriented;

he is given intramuscular

diazepam (Valium), 5 mg. Twenty

minutes later he is unresponsive.

Physical examination reveals a stuporous

but arousable man who has

papilledema and asterixis. Arterial

blood gases are pH 7.17; PO2 42

kPa; PCO2 95 kPa. The best immediate

therapy would be to

a. Correct hypoxemia with high-flow

nasal oxygen

b. Correct acidosis with sodium bicarbonate

c. Administer intravenous dexamethasone,

10 mg

d. Intubate the patient

e. Call for neurosurgical consultation

58. Dopamine is a frequently used

drug in critically ill patients because

a. At high doses it increases splanchnic

flow

b. At high doses it increases coronary

flow

c. At low doses it decreases heart rate

d. At low doses it lowers peripheral

resistance

e. It inhibits catecholamine release

59. Which statement regarding

transmission of viral illness through

homologous blood transfusion is

true?

a. The most common viral agent

transmitted via blood transfusion

in the United States is human

immune deficiency virus (HIV)

b. Blood is routinely tested for cytomegalovirus

(CMV) because CMV

infection is often fatal

c. The most frequent infectious complication

of blood transfusion continues

to be viral meningitis

d. Up to 10% of those who develop

posttransfusion hepatitis will develop

cirrhosis or hepatoma or both

e. The etiologic agent in posttransfusion

hepatitis remains undiscovered

Critical Care:Anesthesiology, Blood Gases, Respiratory Care 35

Items 60-61

A 68-year-old hypertensive

man undergoes successful repair

of a ruptured abdominal aortic

aneurysm. He receives 9 L Ringer's

lactate solution and 4 units of

whole blood during the operation.

Two hours after transfer to the surgical

intensive care unit, the following

hemodynamic parameters are

obtained:

• Systemic blood pressure (BP):

90/60 mm Hg

• Pulse rate: 110 beats/min

• Central venous pressure (CVP):

7 mm Hg

• Pulmonary artery pressure:

28/10 mm Hg

• Pulmonary capillary wedge pressure:

8 mm Hg

• Cardiac output: 1.9 L/min

• Systemic vascular resistance: 35

Woods units (normal is 24-30

Woods units)

• PaO2: 140 kPa (FiO2: 0.45)

• Urine output: 15 mL/h (specific

gravity: 1.029)

• Hematocrit: 35%

60. Propermanagementwouldnow

call for

a. Administration of a diuretic to

increase urine output

b. Administration of a vasopressor

agent to increase systemic blood

pressure

c. Administration of a fluid challenge

to increase urine output

d. Administration of a vasodiluting

agent to decrease elevated systemic

vascular resistance

e. A period of observation to obtain

more data

61. The patient then has an

improvement in all hemodynamic

parameters. However, 6 h later he

develops ST segment depression,

and a 12-lead cardiogram shows

anterolateral ischemia. New hemodynamic

parameters are obtained:

• Systemic BP: 70/40 mm Hg

• Pulse rate: 100 beats/min

• Central venous pressure (CVP):

18 cm H2O

• Pulmonary capillary wedge pressure

(PCWP): 25 mm Hg

• Cardiac output: 1.5 L/min

• Systemic vascular resistance: 25

Woods units

The single best pharmacologic

intervention would be

a. Sublingual nitroglycerin

b. Intravenous nitroglycerin

c. A short-acting beta blocker

d. Sodium nitroprusside

e. Dobutamine

36 Surgery

62. A 56-year-old man undergoes

a left upper lobectomy. An epidural

catheter is inserted for postoperative

pain relief. Ninety minutes

after the first dose of epidural morphine,

the patient complains of

itching and becomes increasingly

somnolent. Blood gas measurement

reveals the following: pH 7.24;

PaCO2 58; PaO2 100; HCO3− 28. Initial

therapy should include

a. Endotracheal intubation

b. Intramuscular diphenhydramine

(Benadryl)

c. Epidural naloxone

d. Intravenous naloxone

e. Alternative analgesia

63. If end-diastolic pressure is

held constant, increasing which of

the following will increase the cardiac

index?

a. Peripheral vascular resistance

b. Pulmonary wedge pressure

c. Heart rate

d. Systemic diastolic pressure

e. Viscosity of the blood

64. A 73-year-old woman with a

long history of heavy smoking

undergoes femoral artery-popliteal

artery bypass for resting pain in her

left leg. Because of serious underlying

respiratory insufficiency, she

continues to require ventilatory

support for 4 days after her operation.

As soon as her endotracheal

tube is removed, she begins complaining

of vague upper abdominal

pain. She has daily fever spikes to

39°C (102.2°F) and a leukocyte

count of 18,000/μL. An upper

abdominal ultrasonogram reveals a

dilated gallbladder, but no stones

are seen. A presumptive diagnosis

of acalculous cholecystitis is made.

You would recommend

a. Nasogastric suction and broadspectrum

antibiotics

b. Immediate cholecystectomy with

operative cholangiogram

c. Percutaneous drainage of the gallbladder

d. Endoscopic retrograde cholangiopancreatography

(ERCP) to

visualize and drain the common

bile duct

e. Provocation of cholecystokinin release

by cautious feeding of the

patient

Critical Care:Anesthesiology, Blood Gases, Respiratory Care 37

Items 65-67

A 32-year-old man undergoes a distal pancreatectomy, splenectomy,

and partial colectomy for a gunshot wound to the left upper quadrant of

the abdomen. One week later he develops a shaking chill in conjunction

with a temperature spike to 39.44°C (103°F). His blood pressure is 70/40

mm Hg with a pulse of 140 beats/min and his respiratory rate is 45

breaths/min. He is transferred to the ICU where he is intubated and a

Swan-Ganz catheter is placed.

65. Which of the following would be most consistent with this patient's

preintubation arterial blood gas measurement?

38 Surgery

pH PaCO2 PaO2

a. 7.31 48 61

b. 7.52 28 76

c. 7.45 40 77

d. 7.40 30 72

e. 7.40 48 94

66. Which of the following is consistent with the expected initial Swan-

Ganz catheter readings?

a. Cardiac output: 7.0 L/min

b. Peripheral vascular resistance: 1660 dynes

c. Pulmonary artery pressure: 50/20 mm Hg

d. Pulmonary capillary wedge pressure: 16 mm Hg

e. Central venous pressure: 18 mm Hg

67. Initial therapy for this patient would include

a. Furosemide

b. Propranolol

c. Sodium nitroprusside

d. Broad-spectrum antibiotics

e. Laparotomy

68. The preoperative characteristics

of patients likely to experience

postoperative ischemia after noncardiac

surgery include

a. Angina

b. More than three premature ventricular

contractions (PVCs) per minute

c. Dyspnea on exertion

d. Tricuspid regurgitation

e. Age greater than 60 years

69. Which statement regarding

local anesthetics is true?

a. When used for infiltration anesthesia,

the maximal safe total dose of

lidocaine is 3.0 mg per kilogram of

body weight

b. Addition of epinephrine (1:200,000)

to the solution of lidocaine, procaine,

or bupivacaine does not increase the

maximal safe total dose but increases

the duration of the block

c. Numerous individuals are hypersensitive

to local anesthetics

d. A local anesthetic in contact with a

nerve trunk will cause sensory loss

but not motor paralysis in the area

innervated

e. Rapid systemic administration of

local anesthetics may produce death

without signs of CNS stimulation

70. Compensatory mechanisms

during acute hemorrhage include

a. Decreased cerebral and coronary

blood flow

b. Decreased myocardial contractility

c. Renal and splanchnic vasodilation

d. Increased respiratory rate

e. Decreased renal sodium resorption

71. The correlation between pulmonary

capillary wedge pressure

(PCWP) and left ventricular enddiastolic

pressure (LVEDP) as measured

by pulmonary artery

catheterization may be adversely

affected by

a. Aortic stenosis

b. Aortic regurgitation

c. Coronary artery disease

d. Positive-pressure ventilation with

positive end-expiratory pressure/

continuous positive airway pressure

(PEEP/CPAP)

e. Bronchospasm

72. Which statement regarding

perioperative risk of stroke in

patients with a past history of

stroke is true?

a. The mortality after postoperative

stroke is high

b. Most postoperative strokes occur

directly after surgery and appear

related to operative events

c. The risk of stroke correlates with

the length of time since previous

stroke

d. General state of health and severity

of illness as measured by ASA classification

are significant predictors

of recurrent stroke

e. The risk of stroke correlates with a

history of multiple strokes or poststroke

transient ischemic attacks

(TIAs)

Critical Care:Anesthesiology, Blood Gases, Respiratory Care 39

73. An 18-year-old woman develops

urticaria and wheezing after an

injection of penicillin. Her blood

pressure is 120/60 mm Hg, heart

rate is 155 beats/min, and respiratory

rate is 30 breaths/min. Immediate

therapy should include

a. Intubation

b. Epinephrine

c. Beta blockers

d. Iodine

e. Fluid challenge

74. During blood transfusion,

clotting of transfused blood is associated

with

a. ABO incompatibility

b. Minor blood group incompatibility

c. Rh incompatibility

d. Transfusion through Ringer's lactate

e. Transfusion through 5% dextrose

and water

75. When an arterial blood gas

determination of PCO2 40 kPa is

obtained

a. There is probably a paradoxical

aciduria

b. Alveolar ventilation is adequate

c. Arterial PO2 will indicate the adequacy

of alveolar ventilation

d. Arterial PO2 will indicate the degree

of ventilation-perfusion mismatch

e. Arterial PO2 can be safely predicted

to exceed 90 kPa on room air

76. An obese 50-year-old woman

undergoes a laparoscopic cholecystectomy.

In the recovery room she

is found to be hypotensive and

tachycardic. Her arterial blood

gases reveal a pH of 7.29, partial

pressure of oxygen of 60 kPa, and

partial pressure of CO2 of 54 kPa.

The most likely cause of this

woman's problem is

a. Acute pulmonary embolism

b. CO2 absorption from induced

pneumoperitoneum

c. Alveolar hypoventilation

d. Pulmonary edema

e. Atelectasis from high diaphragm

77. Among patients who require

nutritional resuscitation in an

intensive care unit, the best evidence

that nutritional support is

adequate is

a. Urinary nitrogen excretion levels

b. Total serum protein level

c. Serum albumin level

d. Serum transferrin levels

e. Respiratory quotient

78. Paradoxical aciduria (the

excretion of acid urine in the presence

of metabolic alkalosis) may

occur in the presence of

a. Release of inappropriate antidiuretic

hormone

b. Severe crush injury

c. Acute tubular necrosis

d. Gastric outlet obstruction

e. An eosinophilic pituitary adenoma

40 Surgery

79. If a patient suffered a pulmonary

arterial air embolism during

an open thoracotomy, the

anesthesiologist's most likely observation

would be

a. Unexpected systemic hypertension

b. Rising right atrial filling pressures

c. Reduced systemic arterial oxygen

saturation

d. Rising systemic CO2 partial pressures

e. Falling end-tidal CO2

80. A 72-year-old man undergoes

resection of an abdominal aneurysm.

He arrives in the ICU with

a core temperature of 33°C

(91.4°F) and shivering. The physiologic

consequence of the shivering

a. Rising mixed venous oxygen saturation

b. Increased production of carbon

dioxide

c. Decreased consumption of oxygen

d. Rising base excess

e. Decreased minute ventilation

81. To prepare for operating on a

patient with a bleeding history

diagnosed as von Willebrand's disease

(recessive), you would give

a. High-purity factor VIII:C concentrates

b. Low-molecular-weight dextran

c. Fresh frozen plasma (FFP)

d. Cryoprecipitate

e. Whole blood

82. Which of the following clinical

situations is an indication for treatment

with extracorporeal membrane

oxygenation (ECMO)?

a. A 1-day-old, full-term, anencephalic

4-kg boy suffering from

meconium aspiration syndrome

and hypoxia

b. A 75-year-old man with Alzheimer's

disease, severe pneumonia,

and elevated pulmonary

arterial pressure

c. A neonate with a diagnosis of

severe pulmonary hypoplasia who

is in respiratory failure

d. A 5-year-old girl with rhabdomyosarcoma

metastatic to the

lungs

e. Preoperatively in a 3-day-old boy

with a congenital diaphragmatic

hernia

83. The accidental aspiration of

gastric contents into the tracheobronchial

tree should be initially

treated by

a. Tracheal intubation and suctioning

b. Steroids

c. Intravenous fluid bolus

d. Cricothyroidotomy

e. High positive end-expiratory pressure

Critical Care:Anesthesiology, Blood Gases, Respiratory Care 41

84. In performing a tracheostomy,

authorities agree that

a. The strap muscles should be

divided

b. The thyroid isthmus should be preserved

c. The trachea should be entered at

the second or third cartilaginous

d. Only horizontal incisions should

be used

e. Formal tracheostomy is preferable

to cricothyroidotomy as an emergency

procedure

85. If malignant hyperthermia is

suspected intraoperatively

a. Complete the procedure but pretreat

with dantrolene prior to future

elective surgery

b. Administer inhalational anesthetic

agents

c. Administer succinylcholine

d. Hyperventilate with 100% oxygen

e. Acidify the urine to prevent myoglobin

precipitation in the renal

tubules

86. Central venous pressure (CVP)

may be decreased by

a. Pulmonary embolism

b. Hypervolemia

c. Positive-pressure ventilation

d. Pneumothorax

e. Gram-negative sepsis

87. Characteristics of continuous

arteriovenous hemofiltration

(CAVH) in the treatment of surgical

patients with acute renal failure

include

a. CAVH is useful only in hemodynamically

stable patients

b. CAVH requires placement of largebore

(8 French) arterial and venous

catheters, usually in the femoral

vessels

c. CAVH is not effective in treating

hypervolemia

d. Continuous heparinization of the

patient who undergoes CAVH is

unnecessary

e. During CAVH, blood flow is maintained

by a mechanical extracorporeal

pump-oxygenator

88. Signs and symptoms of unsuspected

Addison's disease include

a. Hypothermia

b. Hypokalemia

c. Hyperglycemia

d. Hyponatremia

e. Hypervolemia

89. The etiologic factor implicated

in the development of pulmonary

insufficiency following major nonthoracic

trauma is

a. Aspiration

b. Atelectasis

c. Fat embolism syndrome

d. Fluid overload

e. Pneumonia

42 Surgery

90. For the severely traumatized

patient requiring airway management

a. Awake endotracheal intubation is

indicated in patients with penetrating

ocular injury

b. Steroids have been shown to be of

value in the treatment of aspiration

of acidic gastric secretions

c. The stomach may be assumed to be

empty only if a history is obtained

indicating no ingestion of food or

liquid during the prior 8 h

d. Intubation should be performed in

the emergency room if the patient

is unstable

e. Cricothyroidotomy is contraindicated

in the presence of maxillofacial

injuries

91. Treatment for clostridial myonecrosis

(gas gangrene) includes

which of the following measures?

a. Administration of an antifungal

agent

b. Administration of antitoxin

c. Wide debridement

d. Administration of hyperbaric oxygen

e. Early closure of tissue defects

92. An abnormal ventilationperfusion

ratio (Qs/Qr) in the postoperative

patient has been associated

with

a. Pulmonary thromboembolism

b. Lower abdominal surgery

c. Starvation

d. The upright position

e. Increased cardiac output

93. Correct statements concerning

drowning or near-drowning

include which of the following?

a. The prognosis for recovery of cerebral

function in affected persons is

better if submersion occurs in

warm water rather than extremely

cold water

b. A majority of victims will demonstrate

a severe metabolic alkalosis

c. Prompt administration of corticosteroids

to affected persons has

been shown to decrease the extent

of pulmonary membrane damage

d. Renal damage may occur in

affected persons as a result of

hemoglobinuria

e. The most important initial treatment

of drowning victims is emptying

the stomach of swallowed water

94. Spontaneous retroperitoneal

hemorrhage during anticoagulant

therapy

a. Is best confirmed by bleeding scan

b. Is equally likely with parenteral

and oral anticoagulants

c. May mimic an acute surgical

abdomen

d. Frequently requires laparotomy for

ligation of the bleeding site

e. Is seen in over 30% of patients

receiving long-term anticoagulation

Critical Care:Anesthesiology, Blood Gases, Respiratory Care 43

95. Correct statements concerning

smoke inhalation ("smoke poisoning")

include which of the following?

a. Smoke poisoning is a thermal

rather than chemical injury

b. Carbon monoxide levels are not

likely to be elevated unless there is

evidence of skin or oropharyngeal

burns

c. Chest x-rays during the early

postinhalation period show a characteristic

"ground glass" appearance

d. Damage to the upper respiratory

tract is common and is usually

found on laryngoscopy

e. Patients with elevated carboxyhemoglobin

levels should be hospitalized

for a minimum of 24 h

96. Indications for surgical intervention

to remove smuggled drug

packets that have been ingested

include

a. Refusal to take high doses of laxatives

b. Refusal to allow endoscopic

retrieval

c. Refusal to allow digital rectal disimpaction

d. Intraintestinal drug packets evident

on abdominal x-ray in an asymptomatic

smuggler

e. Signs of toxicity from leaking drug

packets

44 Surgery

DIRECTIONS: Each group of questions below consists of lettered

options followed by numbered items. For each numbered item, select the

appropriate lettered option(s). Each lettered option may be used once,

more than once, or not at all. Choose exactly the number of options

indicated following each item.

Items 97-99

Match the side effects below

with the appropriate anesthetic.

a. Nitrous oxide (N2O)

b. Halothane

c. Methoxyflurane

d. Enflurane

e. Morphine

97. Seizures (SELECT 1 AGENT)

98. Decreased peripheral resistance

(SELECT 1 AGENT)

99. Possible worsening of distention

in bowel obstruction (SELECT

1 AGENT)

Items 100-102

For each clinical problem

described below, select the appropriate

methods of physiologic monitoring.

a. Arterial catheterization

b. Central venous catheterization

c. Pulmonary artery catheterization

d. Ventilation monitoring

e. Blood gas monitoring

f. Intracranial pressure monitoring

g. Metabolic monitoring

h. Continuous ECG monitoring

100. A 74-year-old man has a 5-h

elective operation for repair of an

abdominal aortic aneurysm. He

had a small myocardial infarction 3

years earlier. In the ICU on the first

postoperative day, he may be ready

for extubation and is receiving

dobutamine by continuous infusion.

(SELECT 5 METHODS)

101. A 22-year-old rugby player is

rushed to the operating room

because of abdominal tenderness,

tachycardia, and hypotension following

a collision with another

player. He is otherwise healthy. At

exploration a significant hemoperitoneum

is found due to a ruptured

spleen. (SELECT 3 METHODS)

102. A comatose 28-year-old

woman who sustained a depressed

skull fracture in an automobile collision

receives enteral nutrition via

a nasoenteric feeding tube. She has

been unconscious for 6 wk. Her

vital signs are stable and she

breathes room air. Following her

initial decompressive craniotomy,

she has returned to the operating

room twice for intracranial bleeding.

(SELECT 3 METHODS)

Critical Care:Anesthesiology, Blood Gases, Respiratory Care 45

46 Surgery

Items 103-105

For each test listed below, select the coagulation factors whose functions

are measured.

a. Factor II

b. Factor V

c. Factor VII

d. Factor VIII

e. Factor IX

f. Factor X

g. Factor XI

h. Factor XII

i. Platelets

j. Fibrinogen

103. Prothrombin time (SELECT 5 FACTORS)

104. Partial thromboplastin time (SELECT 8 FACTORS)

105. Bleeding time (SELECT 1 FACTOR)

CRITICAL CARE:

ANESTHESIOLOGY, BLOOD

GASES, RESPIRATORY CARE

Answers

51. The answer is c. (Greenfield, 2/e, p 1984.) Although hypoventilation,

incomplete oxygen diffusion, and pulmonary shunts all are causes of

hypoxemia, the most common cause is ventilation-perfusion inequality.

The mismatch of ventilation and blood flow occurs to some degree in the

normal upright lung but may become extreme in the diseased lung. The

three indices used to measure ventilation-perfusion inequality are alveolararterial

PO2 difference, physiologic shunt (venous admixture), and alveolar

dead space. Elevated 2,3-diphosphoglycerate (2,3-DPG) levels shift the

oxygen dissociation curve to the right and thereby augment tissue oxygenation.

This elevation does not result in hypoxemia.

52. The answer is d. (Greenfield, 2/e, pp 221-225.) Anticipation and early

aggressive treatment of pulmonary insufficiency by mechanical ventilatory

support are critical in managing the seriously ill patient. Readily measured

changes that can be used to determine either the need for intubation or the

appropriate time for weaning from mechanical respiratory support include

arterial blood gas levels, dead space-tidal volume ratio (VD/VT), alveolararterial

oxygen tension difference [(A-a)DO2], vital capacity, and respiratory

rate. Indications for mechanical ventilation include a respiratory rate over

35 breaths/min, vital capacity less than 15 mL/kg, (A-a)DO2 greater than

350 kPa after 15 min on 100% oxygen, VD/VT greater than 0.6, PaO2 less

than 60 kPa, and PaCO2 greater than 60 kPa.

53. The answer is e. (Schwartz, 7/e, pp 97-98.) Whenever a hemolytic

reaction caused by an incompatible blood transfusion is suspected, the

transfusion should be stopped immediately. A Foley catheter should be

inserted, and hourly urine output should be monitored. Renal damage

caused by precipitation of hemoglobin in the renal tubules is the major

47

serious consequence of hemolysis. This precipitation is inhibited in an

alkaline environment and is promoted in an acid environment. Stimulating

diuresis with 100 mL of 20% mannitol and alkalinizing the urine with 45

meq sodium bicarbonate intravenously are indicated procedures. Fluid

and potassium intake should be restricted in the presence of severe oliguria

or anuria.

54. The answer is b. (Greenfield, 2/e, p 439.) Nitrous oxide (N2O) has a

low solubility compared with other inhalation anesthetics. Its blood:gas

partition coefficient is 0.47, and it is 30 times more soluble in blood than

is nitrogen (N2). N2O is also the only anesthetic gas less dense than air. As

a result of these properties, N2O may cause progressive distention of airfilled

spaces during prolonged anesthesia. This can lead to undesirable situations

whenever there is a pneumothorax or intestinal obstruction or

when procedures like pneumoventriculography (in which the intracranial

air space is not free to expand in response to the diffusion of gas into the

ventricles) are performed. In each of these cases the N2O diffuses into the

gas-filled compartment faster than N2 can diffuse out. Since the typical

mixture of ingested air (or pneumothorax air) is 80% N2 and the usual mixture

of nitrous oxide anesthetic gas is 80% N2O, rapid increase in the size

of gas-filled chambers with potentially serious consequences may occur.

55. The answer is a. (Schwartz, 7/e, pp 693-694.) Adult respiratory distress

syndrome (ARDS) has been called "shock lung" or "traumatic wet

lung" and occurs under a variety of circumstances. Clinically, its manifestations

can range from minimal dysfunction to unrelenting pulmonary failure.

Three major physiologic alterations include (1) hypoxemia usually

unresponsive to elevations of inspired oxygen concentration; (2) decreased

pulmonary compliance, as the lungs become progressively "stiffer" and

harder to ventilate; and (3) decreased functional residual capacity. Progressive

alveolar collapse occurs owing to leakage of protein-rich fluid into the

interstitium and the alveolar spaces with the subsequent radiologic picture

of diffuse, fluffy infiltrates bilaterally. Ventilatory abnormalities develop

that result in shunt formation, decreased resting lung volume, and

increased dead space ventilation.

56. The answer is d. (Schwartz, 7/e, pp 496-497.) The shape of the oxygen

dissociation curve translates into several physiologic advantages. The

48 Surgery

relatively flat slope above a PO2 of 50 pKa means that, in this region of the

curve, hemoglobin saturation decreases slightly with decrements in PO2;

loading of oxygen at the alveolar level is therefore affected minimally with

mild to moderate degrees of hypoxemia. The steeper slope at the lower end

of the curve means that, as the hemoglobin becomes desaturated, arterial

PO2 drops only minimally, and a gradient that favors oxygen diffusion into

tissue cells is maintained. Acidosis, a rise in PaCO2, and elevation of temperature

all shift the curve to the right, which enhances tissue oxygen uptake.

Red blood cell organic phosphates, particularly 2,3-diphosphoglycerate

(2,3-DPG), also affect the dissociation curve. Banked blood, being low in

2,3-DPG, shifts the curve to the left and therefore decreases tissue oxygen

uptake. 2,3-DPG levels increase with chronic hypoxia. Chronic lung disease,

therefore, results in a shift of the curve to the right, which enhances

oxygen delivery to peripheral tissues.

57. The answer is d. (Schwartz, 7/e, pp 59-61.) The patient presented in

the question is suffering from acute, life-threatening respiratory acidosis

that has been compounded, if not produced, by the injudicious administration

of a central nervous system depressant. While hypoxemia must also

be corrected, the immediate task is to correct the acidosis caused by carbon

dioxide accumulation. Both disturbances can be resolved by skillful endotracheal

intubation and by ventilatory support. Sodium bicarbonate and

high-flow nasal oxygen would both be inappropriate. Bicarbonate should

not be administered because buffer reserves are already adequate (serum

bicarbonate is still 34 meq/L based on the Henderson-Hasselbalch equation).

Nasal oxygen administration is not warranted because both acidemia

and hypoxemia are themselves potent stimulants to spontaneous ventilation.

Headache, confusion, and papilledema are all signs of acute carbon

dioxide retention and do not imply the presence of a structural intracranial

lesion.

58. The answer is b. (Schwartz, 7/e, pp 454-455.) Dopamine has a variety

of pharmacologic characteristics that make it useful in critically ill

patients. In low doses (1-5 mg/kg/min), dopamine affects primarily the

dopaminergic receptors. Activation of these receptors causes vasodilation

of the renal and mesenteric vasculature and mild vasoconstriction of the

peripheral bed, which thereby redirects blood flow to kidneys and bowel.

At these low doses the net effect on the overall vascular resistance may be

Critical Care Answers 49

slight. As the dose rises (2-10 mg/kg/min), β1-receptor activity predominates

and the inotropic effect on the myocardium leads to increased cardiac

output and blood pressure. Above 10 mg/kg/min, α-receptor stimulation

causes peripheral vasoconstriction, shifting of blood from extremities to

organs, decreased kidney function, and hypertension. At all doses, the

diastolic blood pressure can be expected to rise; since coronary perfusion

is largely a result of the head of pressure at the coronary ostia, coronary

blood flow should be increased.

59. The answer is d. (Goodnough, Am J Surg 159:602-609, 1990.)

Cytomegalovirus (CMV) is harbored in blood leukocytes. CMV infection is

endemic in the United States, and its prevalence increases steadily with

age. While acute CMV infection may cause transient fever, jaundice, and

hepatosplenomegaly in cases of large blood donor exposures, posttransfusion

CMV infection (seroconversion) is not a significant clinical problem in

immunocompetent recipients, and therefore blood is not routinely tested

for the presence of CMV. Posttransfusion non-A, non-B hepatitis, however,

not only represents the most frequent infectious complication of transfusion,

but is associated with an incidence of chronic active hepatitis up to

16% and an 8-10% incidence of cirrhosis or hepatoma or both. The etiologic

agent in over 90% of cases of posttransfusion hepatitis has been identified

as hepatitis C.

60. The answer is c. (Sabiston, 15/e, pp 81-84.) A ruptured abdominal

aneurysm is a surgical emergency often accompanied by serious hypotension

and vascular collapse before surgery and massive fluid shifts with

renal failure after surgery. In this case, all the hemodynamic parameters

indicate inadequate intravascular volume, and the patient is therefore suffering

from hypovolemic hypotension. The low urine output indicates

poor renal perfusion, while the high urine specific gravity indicates adequate

renal function with compensatory free water conservation. The

administration of a vasopressor agent would certainly raise the blood pressure,

but it would do so by increasing peripheral vascular resistance and

thereby further decrease tissue perfusion. The deleterious effects of shock

would be increased. A vasodilating agent to lower the systemic vascular

resistance would lead to profound hypotension and possibly complete vascular

collapse because of pooling of an already depleted vascular volume.

This patient's blood pressure is critically dependent on an elevated systemic

50 Surgery

vascular resistance. To properly treat this patient, rapid fluid infusion and

expansion of the intravascular volume must be undertaken. This can be

easily done with lactated Ringer's solution or blood (or both) until

improvements in such parameters as the pulmonary capillary wedge pressure,

urine output, and blood pressure are noted.

61. The answer is e. (Sabiston, 15/e, pp 84-86.) This patient has developed

pump failure due to a combination of preexisting coronary artery

occlusive disease and high preload following a fluid challenge; afterload

remains moderately high as well because of systemic vasoconstriction in

the presence of cardiogenic shock. Poor myocardial performance is

reflected in the low cardiac output and high pulmonary capillary wedge

pressure. Therapy must be directed at increasing cardiac output without

creating too high a myocardial oxygen demand on the already failing heart.

Administration of nitroglycerin could be expected to reduce both preload

and afterload, but if it is given without an inotrope it would create unacceptable

hypotension. Nitroprusside similarly would achieve afterload

reduction but would result in hypotension if not accompanied by an

inotropic agent. A beta blocker would act deleteriously by reducing cardiac

contractility and slowing the heart rate in a setting in which cardiac output

is likely to be rate dependent. Dobutamine is a synthetic catecholamine

that is becoming the inotropic agent of choice in cardiogenic shock. As a

β1-adrenergic agonist, it improves cardiac performance in pump failure

both by positive inotropy and peripheral vasodilation. With minimal

chronotropic effect, dobutamine only marginally increases myocardial oxygen

demand.

62. The answer is d. (Thoren, Anesth Analg 67:687, 1988.) Thoracic

epidural narcotics have become an increasingly popular means of postoperative

pain relief in thoracic and upper abdominal surgery. Local action on

gamma opiate receptors ensures pain relief and consequent improvement

in respiration without vasodilation or paralysis. The less lipid-soluble opiates

are effective for long periods. Their slow absorption into the circulation

also ensures a low incidence of centrally mediated side effects, such as

respiratory depression or generalized itching. When these do occur, the

intravenous injection of an opiate antagonist is an effective antidote. The

locally mediated analgesia is not affected. One poorly understood side

effect, which is apparently unrelated to systemic levels, is a profound

Critical Care Answers 51

reduction in gastric activity. This may be an important consideration after

thoracic surgery when an early resumption of oral intake is anticipated.

63. The answer is c. (Schwartz, 7/e, p 849.) The cardiac index is computed

by dividing the cardiac output by the body surface area; the cardiac

output is the product of the stroke volume and the heart rate [CI =

CO/BSA; CO = SV × HR; therefore, CI = (SV × HR)/BSA]. An increased

heart rate will directly increase the cardiac output and cardiac index. The

remaining choices in the question will either decrease or not affect the

stroke volume and consequently will not increase the cardiac index.

64. The answer is c. (Schwartz, 7/e, pp 1452-1454.) The development of

acute postoperative cholecystitis is an increasingly recognized complication

of the severe illnesses that precipitate admissions to the intensive care

unit. The causes are obscure but probably lead to a common final pathway

of gallbladder ischemia. The diagnosis is often extremely difficult because

the signs and symptoms may be those of occult sepsis. Moreover, the

patients are often intubated, sedated, or confused as a consequence of the

other therapeutic or medical factors. Biochemical tests, though frequently

revealing abnormal liver function, are nonspecific and nondiagnostic. Bedside

ultrasonography is usually strongly suggestive of the diagnosis when a

thickened gallbladder wall or pericholecystic fluid is present, but radiologic

findings may also be nondiagnostic. If the diagnosis is delayed, mortality

and morbidity are very high. Percutaneous drainage of the gallbladder

is usually curative of acalculous cholecystitis and affords stabilizing palliation

if calculous cholecystitis is present. Some authors have recommended

prophylactic percutaneous drainage of the gallbladder under CT guidance

in any ICU patient who is failing to thrive or has other signs of low-grade

sepsis after appropriate therapy for the primary illness has been provided.

The distractor items in the question are all either too aggressive to be safely

done in critically ill patients or too cautious for a patient with a potentially

fatal complication.

65-67. The answers are 65-b, 66-b, 67-d. (Schwartz, 7/e, pp 115-120.)

The case presented is most consistent with septic shock from a postoperative

intraabdominal abscess. In the early phase of septic shock the respiratory

profile is characterized by mild hypoxia with a compensatory

hyperventilation and respiratory alkalosis. Hemodynamically, a hyperdy-

52 Surgery

namic state is seen with an increase in cardiac output and a decrease in

peripheral vascular resistance in the face of relatively normal central pressures.

Initial therapy is aimed at resuscitation and stabilization. This

includes fluid replacement and vasopressors as well as antibiotic therapy

aimed particularly at gram-negative rods and anaerobes for patients with

presumed intraabdominal collections, especially after bowel surgery.

Laparotomy and drainage of a collection is the definitive therapy but

should await stabilization of the patient and confirmation of the presence

and location of such a collection.

68. The answer is c. (Charlson, Ann Surg 210:637-648, 1989.) The landmark

study by Goldman in 1978 identified cardiac risk factors in noncardiac

surgical patients that included previous infarction (particularly

infarction within 6 mo, but with increased risk continuing for life), functional

impairment such as dyspnea on exertion, age over 70 years, mitral

regurgitation, more than five premature ventricular contractions (PVCs)

per minute, and a tortuous or calcified aorta. Angina alone was not a risk

factor. Subsequent studies by others have differed regarding the importance

of several of these factors, which probably reflects different comorbid

characteristics in the study populations (e.g., diabetes and hypertension).

Additional predictors of perioperative cardiac risk that achieved significance

in some studies but not in others include cardiomegaly, upper

abdominal or intrathoracic surgery, and intraoperative hypotension.

69. The answer is e. (Schwartz, 7/e, p 681.) The maximal safe total dose

of lidocaine administered to a 70-kg man is 4.5 mg/kg, or approximately

30-35 mL of a 1% solution. The addition of epinephrine to lidocaine,

procaine, or bupivacaine not only doubles the duration of infiltration

anesthesia, but increases by one-third the maximal safe total dose by

decreasing the rate of absorption of drug into the bloodstream.

Epinephrine-containing solutions should not, however, be injected into

tissues supplied by end arteries (e.g., fingers, toes, ears, nose, penis).

Hypersensitivity to local anesthetics is uncommon and occurs most

prominently with anesthetics of the ester type (procaine, tetracaine).

While small nerve fibers seem to be most susceptible to the action of local

anesthetics, these agents act on any part of the nervous system and on

every type of nerve fiber. CNS toxicity usually appears as stimulation

followed by depression, probably because of an early selective depression

Critical Care Answers 53

of inhibitory neurons; with a massive overdose, all neurons may be

depressed simultaneously.

70. The answer is d. (Schwartz, 7/e, pp 103-113.) Acute hemorrhage

triggers the potent vasopressor activity of both angiotensin and vasopressin

to increase blood flow to the heart and brain via selective vasoconstriction

of the skin, kidneys, and splanchnic organs. Adrenergic discharge also

results in selective vasoconstriction of skin, renal, and splanchnic vessels.

Myocardial contractility and heart rate are increased, with a resultant

increased cardiac output. Hyperventilation is the typical response to the

metabolic (lactic) acidosis associated with hemorrhagic shock and hypoperfusion.

Aldosterone release, with subsequent increased renal sodium

resorption, is mediated by angiotensin II and ACTH, which prevents further

intravascular depletion.

71. The answer is e. (Greenfield, 2/e, pp 195-197.) When a Swan-Ganz

pulmonary artery catheter is in the wedge position, i.e., isolating the pulmonary

arterial system from the pulmonary capillaries, the measured pulmonary

capillary wedge pressure (PCWP) is usually equivalent to both the

left atrial pressure (LAP) and the left ventricular end-diastolic pressure

(LVEDP). Pathologic processes in the pulmonary vasculature and heart

valves, however, may alter this relationship. Pulmonary vasoocclusive disease

may elevate the PCWP independently of the LAP or LVEDP. Bronchospasm

affecting the airway but not the pulmonary vasculature should

not affect the validity of Swan-Ganz catheter readings. Mitral stenosis and

regurgitation cause increased LAP and PCWP, which result in an overestimated

LVEDP. However, aortic stenosis and regurgitation elevate the PCWP,

LAP, and LVEDP equally. Accurate measurement of PCWP by a Swan-Ganz

catheter may not be possible in the presence of positive airway pressure

with PEEP/CPAP; transmission of the positive airway pressure to the pulmonary

microvasculature via the alveoli, especially in the upper lung

zones, results in measurement of alveolar pressure rather than LAP or

LVEDP. Coronary artery disease does not affect the relationship between

PCWP, LAP, and LVEDP.

72. The answer is a. (Landercasper, Arch Surg 125:986-989, 1990.) In an

8-year, retrospective study of 173 consecutive patients with a documented

medical history of stroke who underwent subsequent general anesthesia

54 Surgery

and surgery (excluding cardiac, cerebrovascular, and neurological surgery),

5 patients (2.9%) had documented postoperative strokes from 3 to 21 days

(mean 12.2 days) after surgery. The risk of stroke did not correlate with

age, sex, history of multiple strokes or poststroke transient ischemic attacks

(TIAs), ASA classification, aspirin use, coronary artery disease, peripheral

vascular disease, intraoperative blood pressure, time since previous stroke,

or cause of previous stroke. The risk of recurrent stroke appears to be comparable

with that of surgical patients who do not have a history of prior

stroke and are undergoing cardiac and peripheral vascular surgery. Most

recurrent strokes occur many hours to days following surgery and do not

appear to be directly related to operative events. The mortality after postoperative

stroke is high.

73. The answer is b. (Schwartz, 7/e, pp 211-212.) This patient is having

an anaphylactoid reaction with destabilization of the cardiovascular and

respiratory systems. Anaphylactoid reactions are most commonly caused

by iodinated contrast media, β-lactam antibiotics (e.g., penicillin), and

Hymenoptera stings. Manifestations of anaphylactoid reactions include

both the lethal (bronchospasm, laryngospasm, hypotension, dysrhythmia)

and the nonlethal (pruritus, urticaria, syncope, weakness, and seizure).

Epinephrine is the initial treatment for laryngeal obstruction and bronchospasm,

followed by histamine antagonists (H1 and H2 blockers), aminophylline,

and hydrocortisone. Vasopressors and fluid challenges may be

given for shock. Conscious patients are usually stabilized with injected or

inhaled epinephrine, while unconscious patients and those with refractory

hypotension or hypoxia should be intubated.

74. The answer is d. (Schwartz, 7/e, pp 97-98.) Most transfusion reactions

are hemolytic and are due to clerical errors that result in administration

of blood with major (ABO) and minor antigen incompatibility.

Interestingly, Rh incompatibility is not associated with intravascular

hemolysis. Administration of blood through hypotonic solutions such as

5% dextrose and water results in swelling of the erythrocytes and hemolysis.

Calcium-containing solutions such as Ringer's lactate cause clotting

within the intravenous line rather than hemolysis and may lead to pulmonary

embolism. Delayed transfusion reactions, caused by a presumed

anamnestic immune response that occurs 3-21 days after blood is infused,

result in a hemolytic anemia.

Critical Care Answers 55

75. The answer is b. (Schwartz, 7/e, pp 494-496.) Because of the highly

efficient diffusion characteristics of the gas carbon dioxide, PaCO2 levels are

reliable indicators of adequacy of alveolar ventilation. A PaCO2 of 40 kPa is

the normal value. Paradoxical aciduria occurs when hypokalemic metabolic

alkalosis is present as the kidney excretes hydrogen ion in an effort to

conserve potassium ion. Though a PaCO2 of 40 kPa is not incompatible with

metabolic alkalosis, it would ordinarily be higher as the patient tries to conserve

carbolic acid by hypoventilating to compensate. PaO2 levels are influenced

by so many other variables (e.g., age, concentration of inspired O2,

altitude) that no inferences can be made about adequacy of alveolar ventilation

from PaO2 alone, nor can PaO2 be safely predicted by the presence of

normocarbia. The ventilation-perfusion mismatch is a reflection of the gradient

between alveolar and arterial oxygen tension in relationship to percentage

of inspired O2.

76. The answer is c. (Schwartz, 7/e, pp 494-496.) Because of the ease

with which carbon dioxide diffuses across the alveolar membranes, the

PaCO2 is a highly reliable indicator of alveolar ventilation. In this postoperative

patient with respiratory acidosis and hypoxemia, the hypercarbia is

diagnostic of alveolar hypoventilation. Acute hypoxemia can occur with

pulmonary embolism, pulmonary edema, and significant atelectasis, but in

all those situations the CO2 partial pressures should be normal or reduced

as the patient hyperventilates to improve oxygenation. The absorption of

gas from the peritoneal cavity may affect transiently the PaCO2, but should

have no effect on oxygenation.

77. The answer is c. (Schwartz, 7/e, pp 36-46.) The serum albumin level

provides a rough estimate of protein nutritional adequacy. The accuracy of

this estimate is affected by the long half-life of albumin (3 wk) and vagaries

of hemodilution. The acute-phase serum proteins have a very short half-life

(hours) and may also provide good short-term indications of nutritional

status. Transferrin is one of these acute-phase proteins, but unfortunately

its levels too are influenced by changes in intravascular volume and, along

with the other acute-phase reactants, rise nonspecifically during acute illness.

All the listed responses provide some useful information about nutrition

and adequacy of replacement.

78. The answer is d. (Schwartz, 7/e, pp 60-62.) The body has elaborate

mechanisms to compensate for metabolic acidosis. Not only do most body

56 Surgery

functions work better in an acidotic state, the patient is able to move

toward correction of the pH by excreting acid urine and by hyperventilating

to "blow off" carbonic acid. On the other hand, we are poorly equipped

to deal with metabolic alkalosis. We cannot hold our breath to save acid

since the respiratory center overrides our efforts as the PaCO2 rises and the

PaO2 falls. The kidney cannot make urine under any circumstance that is

very far above normal pH. In the subtraction alkalosis that accompanies

gastric outlet obstruction with loss of gastric acid by vomiting or suction,

the potassium depletion and volume deficits provoke exchange of sodium

for hydrogen ion in the distal tubule with resultant exacerbation of the

metabolic alkalosis. All the other conditions listed would be expected to

produce acidosis; consequently, acid urine would not be paradoxical.

79. The answer is e. (Schwartz, 7/e, pp 159-161.) Air carried into the

pulmonary arterial vasculature creates an abnormal blood-air interface that

leads to denaturing of plasma proteins and creates amorphous proteinaceous

and cellular debris and endothelial injury. The ensuing increased

capillary permeability results in alveolar flooding. The occlusion of pulmonary

vessels increases the proportion of ventilated but underperfused

alveoli. The increment in dead space results in a drop in end-tidal carbon

dioxide.

80. The answer is b. (Schwartz, 7/e, p 447.) Shivering is the physiologic

effort of the body to generate heat to maintain the core temperature. In

healthy persons, shivering increases the metabolic rate by 3-5 times and

results in increased oxygen consumption and carbon dioxide production.

In critically ill patients these metabolic consequences are almost always

counterproductive and should be prevented with other means employed to

correct systemic hypothermia. In the presence of vigorous shivering, oxygen

debt in the muscles and lactic acidemia develop.

81. The answer is d. (Schwartz, 7/e, pp 78-84.) von Willebrand disease is

similar to true hemophilia in frequency of occurrence. It is being diagnosed

more commonly today because of more reliable assays for factor VIII. This

autosomal dominant disorder (recessive transmission can occur) is characterized

by a diminution in factor VIII:C (procoagulant) activity. The reduction

in activity is not as great as in classic hemophilia, and the clinical

manifestations are more subtle. These manifestations are often overlooked

until an episode of trauma or surgery makes them apparent. Treatment

Critical Care Answers 57

requires correcting the bleeding time and providing factor VIII R:WF (the

von Willebrand factor). Only cryoprecipitate is reliably effective. Highpurity

factor VIII:C concentrates, effective in hemophilia, lack the von

Willebrand factor and are, consequently, undependable.

82. The answer is e. (Schwartz, 7/e, 1720-1721.) Extracorporeal membrane

oxygenation (ECMO) is a form of cardiopulmonary support that is

useful in the setting of potentially reversible pulmonary or cardiac disease.

Treatment of meconium aspiration syndrome, sepsis, pneumonia, and congenital

diaphragmatic hernia (pre- or postoperatively) are thus appropriate

uses. The technique is also applicable in some circumstances as a bridge to

cardiac or lung transplantation since the outlook for survival is quite good

if the child can be maintained in a good physiological state until donor

organs are available. Hypoplastic lungs do not have enough surface area to

perform adequate gas exchange and are unlikely to mature to a point where

they can sustain life. Babies with hypoplastic lungs will be bypass dependent

for life and consequently are not candidates for institution of ECMO

therapy.

83. The answer is a. (Schwartz, 7/e, p 458.) Gastric aspiration is best

treated by tracheal suctioning, oxygen, and positive-pressure ventilation.

Bronchoscopy is helpful if particulate matter is causing bronchial obstruction

or if the vomitus is found to contain particulate material. Bronchial

lavage is no longer recommended, and steroids have not been shown to be

of value. Fluids should be given sparingly because hypervolemia will

worsen the risk of pulmonary edema following aspiration. Tracheostomy

may be indicated for long-term airway management in obtunded or otherwise

severely debilitated patients; however, initial control of the airway

should be by orotracheal intubation whenever possible. High positive endexpiratory

pressure is not required unless respiratory failure develops.

84. The answer is c. (Schwartz, 7/e, p 156.) Although tracheostomy is

occasionally an emergency procedure, it can be more effectively performed

in an operating room where hemostasis and antisepsis are readily achieved.

Most authorities recommend a horizontal incision; however, limited direct

midline incisions have the advantage of not opening any unnecessary tissue

planes and perhaps reducing the incidence of bleeding complications.

Both approaches have advocates. In either case, the skin incision is made

58 Surgery

just below the cricoid cartilage, the strap muscles are spared and retracted,

the thyroid isthmus is divided if necessary, and the trachea is entered at the

second tracheal ring. The second and third tracheal rings are incised vertically,

allowing placement of the tracheostomy tube. The first tracheal ring

and the cricoid cartilage must be left intact.

85. The answer is d. (Schwartz, 7/e, pp 448, 499.) The cause of malignant

hyperthermia is unknown, but it is associated with inhalational anesthetic

agents and succinylcholine. It may develop in an otherwise healthy person

who has tolerated previous surgery without incident. It should be suspected

in the presence of a history of unexplained fever, muscle or connective

tissue disorder, or a positive family history (evidence suggests an

autosomal dominant inheritance pattern). In addition to fever during anesthesia,

the syndrome includes tachycardia, increased O2 consumption,

increased CO2 production, increased serum K+, myoglobinuria, and acidosis.

Rigidity rather than relaxation following succinylcholine injection may

be the first clue to its presence. Treatment of malignant hyperthermia

should include prompt conclusion of the operative procedure and cessation

of anesthesia, hyperventilation with 100% oxygen, and administration

of intravenous dantrolene. The urine should be alkalinized to protect the

kidneys from myoglobin precipitation. If reoperation is necessary, one

should premedicate heavily, alkalinize the urine, and avoid depolarizing

agents such as succinylcholine. Pretreatment for 24 h with dantrolene is

helpful; it is thought to act directly on muscle fiber to attenuate calcium

release.

86. The answer is e. (Schwartz, 7/e, pp 487-493.) Determination of CVP

is an integral part of the overall hemodynamic assessment of the patient.

This pressure can be affected by a variety of factors including those of cardiac,

noncardiac, and artifactual origin. Venous tone, right ventricular

compliance, intrathoracic pressure, and blood volume all influence CVP.

Vasoconstrictor drugs, positive pressure, ventilation (with and without

PEEP), mediastinal compression, and hypervolemia all increase CVP. Acute

pulmonary embolism, when clinically significant, elevates CVP by causing

right ventricular overload and increased right atrial pressure. Sepsis, on the

other hand, decreases CVP through both the release of vasodilatory mediators

and the loss of intravascular plasma volume due to increased capillary

permeability.

Critical Care Answers 59

87. The answer is b. (Greenfield, 2/e, pp 238-239.) Continuous arteriovenous

hemofiltration (CAVH) is a relatively new method of therapy for

acute renal failure in the intensive care unit. Continuous blood flow is

maintained by the hydrostatic pressure gradient between an inflowing arterial

cannula and the venous cannula that returns blood to the patient. The

blood passes through an extracorporeal membrane, which clears an ultrafiltrate

up to 12 L per day. This volume is replaced with an intravenous

solution at a rate that achieves the desired fluid balance. CAVH in the surgical

patient with acute renal failure allows a slow and continuous removal

of fluid and is particularly advantageous in the volume-overloaded patient.

Unlike traditional hemodialysis, it can be used over a wide range of blood

pressures in the unstable patient. Solutes (such as urea nitrogen and potassium)

that are not in the replacement intravenous fluid are also cleared.

The main complications associated with CAVH relate to vascular access

problems: arterial thrombosis, aneurysm, fistula formation, and infection.

Anticoagulation, with the concomitant bleeding risks, must be maintained

to prevent thrombosis of the filter and cannulae. The potential for electrolyte

imbalance during long-term CAVH requires careful monitoring.

88. The answer is d. (Greenfield, 2/e, pp 204-205.) Clinical manifestations

of adrenocortical insufficiency include hyperkalemia, hyponatremia,

hypoglycemia, fever, weight loss, and dehydration. There is excessive

sodium loss in the urine, contraction of the plasma volume, and perhaps

hypotension or shock. Classic hyperpigmentation is present in chronic

Addison's disease only. Addison's disease may present in newborns as a

congenital atrophy, as an insidious chronic state often due to tuberculosis,

as an acute dysfunction secondary to trauma or adrenal hemorrhage, or as

a semiacute adrenal insufficiency seen during stress or surgery. In this last

instance, signs and symptoms include nausea, lassitude, vomiting, fever,

progressive salt wasting, hyperkalemia, and hypoglycemia. It may be confirmed

by measurements of urinary Na+ loss and absence of response to

ACTH.

89. The answer is c. (Schwartz, 7/e, pp 693-694.) Posttraumatic pulmonary

insufficiency in the absence of significant thoracic trauma has been

attributed to a wide variety of etiologic agents, including aspiration, simple

atelectasis, lung contusion, fat embolism, pneumonia, pneumothorax, pulmonary

edema, and pulmonary thromboembolism. In a landmark mono-

60 Surgery

graph entitled Respiratory Distress Syndrome of Shock and Trauma, Blaisdell

and Lewis identified fat embolism syndrome as the etiologic factor. The

mechanism of this condition appears to be pulmonary alveolar injury due

to the mobilization of free fatty acids in the blood as an adrenergic response

to trauma, rather than pulmonary injury from embolization of fat globules

from fractured bones, as was originally thought.

90. The answer is d. (Sabiston, 15/e, p 296.) Securing a stable airway is

one of the most fundamental and important aspects of the management of

the severely injured patient. The level of control required will vary from a

simple oropharyngeal airway to tracheostomy, depending on the clinical

situation. Full control of the airway should be secured in the emergency

room if the patient is unstable. Endotracheal intubation will usually be the

method chosen, but one should be prepared to do a tracheotomy if

attempts at peroral or pernasal intubation are failing or are impractical

because of maxillofacial injuries. The most dangerous period is just prior to

and during the initial attempts to get control of the airway. Manipulation of

the oronasopharynx may provoke combative behavior or vomiting in a

patient already confused by drugs, alcohol, hypoxia, or cerebral trauma.

The risk of aspiration is high during these initial attempts, and one should

make no assumptions about the state of the contents of the patient's stomach.

Antacids are recommended just prior to the intubation attempt, if feasible.

Although steroids have been recommended in the past, they are no

longer considered of value in the management of aspiration of acidic gastric

juice. The best management requires prevention of the complication of

aspiration. In a reasonably cooperative patient, awake intubation with topical

anesthesia may help to avoid some of the risks of hypotension, arrhythmia,

and aspiration associated with the induction of anesthesia. If awake

intubation is inappropriate, then an alternative is rapid-sequence induction

with a thiobarbiturate followed by muscle paralysis with succinylcholine. If

elevated intracranial pressure is suspected, or if a penetrating eye injury

exists, awake intubation is contraindicated.

91. The answer is c. (Sabiston, 15/e, pp 269-270.) Necrotizing skin and

soft tissue infections may produce insoluble gases (hydrogen, nitrogen,

methane) through anaerobic bacterial metabolism. While the term "gas

gangrene" has come to imply clostridial infection, gas in tissues is more

likely not to be due to Clostridium species but rather to other facultative and

Critical Care Answers 61

obligate anaerobes, particularly streptococci. Though fungi have also been

implicated, they are less often associated with rapidly progressive infections.

Treatment for necrotizing soft tissue infections includes repeated

wide debridement, with wound reconstruction delayed until a stable,

viable wound surface has been established. The use of hyperbaric oxygen

in the treatment of gas gangrene remains controversial, due to lack of

proven benefit, difficulty in transporting critically ill patients to hyperbaric

facilities, and the risk of complications. Antitoxin has neither a prophylactic

nor a therapeutic role in the treatment of myonecrosis.

92. The answer is a. (Sabiston, 15/e, pp 1798-1799.) Abnormalities of

ventilation-perfusion ratio result from the shunting of blood to a hypoventilated

lung or from the ventilation of hypoperfused regions of lung tissue.

When this imbalance is extreme, as following massive pulmonary

thromboembolism, the effect is life-threatening hypoxemia. Other common

predisposing factors in the postoperative patient that contribute to

this maldistribution include the assumption of a supine position, thoracic

and upper abdominal incisions, obesity, atelectasis, and reduced cardiac

output.

93. The answer is d. (Shoemaker, 2/e, pp 39-41.) The metabolic and

physiologic effects of drowning and near-drowning depend upon variables

that include fluid temperature, extent of aspiration, and whether the aspirate

is fresh water or sea water. Cold-water submersion decreases oxygen

consumption and results in preferential shunting of blood flow to the heart

and brain. This shunting prolongs the period of submersion that can be

endured without irreversible cerebral damage. Return of normal cerebral

function after as long as 40 min of submersion in extremely cold water has

been reported. One should also remember that cooling below 30°C (86°F)

often causes cardiac arrhythmias. Ten percent of affected patients do not

aspirate fluid but succumb to asphyxia because of breath holding or

laryngospasm. Seventy percent have a significant metabolic acidosis requiring

administration of sodium bicarbonate. Significant electrolyte and blood

volume changes may or may not be present, depending on the degree of

aspiration and toxicity of the fluid medium. Renal damage may occur as a

result of hemoglobinuria (from hemolysis), acidosis, hypoxia, or changes

in renal blood flow. The most important initial treatment of drowning victims

is ventilation. Mouth-to-mouth or mouth-to-nose ventilation should

62 Surgery

be begun as soon as possible. Corticosteroids and prophylactic antibiotics

are not recommended for the prevention of pulmonary complications.

However, some workers feel that steroids may be of value in managing the

complication of cerebral edema.

94. The answer is c. (Greenfield, 2/e, pp 95-98.) Major hemorrhage that

requires the termination of anticoagulant therapy occurs in up to 15% of

anticoagulated patients. Spontaneous retroperitoneal hemorrhage constitutes

a small subset of such cases and can be a fatal complication. Heparin

is much more frequently associated with spontaneous retroperitoneal hemorrhage

than are oral agents. Advanced patient age and poor regulation of

coagulation times also increase the likelihood of bleeding complications.

Most cases of retroperitoneal hemorrhage present with flank pain and signs

of peritoneal irritations suggestive of an acute intraabdominal process. CT

scans are most useful in confirming the diagnosis and following the course

of the bleeding. Successful management is usually nonoperative and consists

of the discontinuation of anticoagulants, administration of vitamin K

or protamine, possible transfusion of clotting factors, and repletion of

intravascular volume with intravenous fluids.

95. The answer is e. (Pruitt, J Trauma 30:363-368, 1990.) Smoke inhalation

injuries ("smoke poisoning") and asphyxia account for almost onethird

of all fire fatalities. As opposed to respiratory burns, which are

thermal injuries of the upper respiratory tract, smoke inhalation is a chemical

injury to the distal tracheobronchial tree and alveoli. Most patients

admitted for this injury have elevated carbon monoxide levels, but a

minority will have physical evidence of skin burns (20%) or of oropharyngeal

burns (25%). Visible damage to the respiratory tract is not a frequent

finding. Chest films initially are often negative even in those patients who

subsequently develop respiratory failure from pulmonary edema or pneumonitis.

Patients with elevated carboxyhemoglobin levels or evidence of

smoke inhalation should be hospitalized for a minimum of 24 h for observation

regardless of normal arterial blood gases and chest x-ray.

96. The answer is e. (Robinson, Surgery 113:709-711, 1993.) Some drug

smugglers, often called "body packers" or "mules," ingest cocaine- or

heroin-filled packets and retrieve them at a later date from their stools. The

drugs are usually contained in latex or plastic packets. Rupture or leakage

Critical Care Answers 63

of even one bag carries the risk of severe toxicity and death. Although conservative

medical management with moderate doses of laxatives is usually

safe in stable body packers, close physiologic monitoring is necessary until

all packets are passed. High doses of laxatives, digital rectal disimpaction,

or endoscopic removal create a high risk of rupture of the bags and therefore

are generally discouraged. Emergency surgery is indicated when complications

develop.

97-99. The answers are 97-d, 98-e, 99-a. (Greenfield, 2/e, pp 438-443.)

Nitrous oxide (N2O) is a frequently used inhalation analgesic. However,

because the minimum alveolar anesthetic concentration (MAC) is so high

(over 100), true anesthesia at 1 atm pressure cannot be obtained without

compromising oxygen delivery to the patient. Since nitrous oxide is 30

times more soluble than nitrogen in blood, it enters a collection of trapped

air at a rate faster than that at which nitrogen leaves the collection. Thus,

the trapped air will increase in volume. If the trapped air is a result of

bowel obstruction, intestinal distention will increase.

Halothane is a very potent anesthetic with an MAC of 0.75. Cardiovascular

depression results from a number of different mechanisms.

Hypotension and decreased cardiac output have been associated with a

direct depression of myocardial muscle fibers and peripheral vascular

smooth muscle fibers. An effect on the medullary vasomotor centers as well

as on sympathetic ganglionic transmissions to the heart has been reported.

Enflurane is a halogenated inhalation anesthetic with an MAC of 1.2.

It is similar to halothane in its anesthetic characteristics. However, in a

small number of normal patients it may induce electroencephalographic

changes similar to those seen in epilepsy.

Methoxyflurane is the most potent and least volatile halogenated

inhalation anesthetic, with an MAC of 0.16. Its clinical use has been curtailed

because of the high risk of nephrotoxicity of the free fluoride ions

released during its biodegradation.

Morphine is a potent narcotic agent. Its use during general anesthesia

can potentiate the analgesic effects of the inhalation agents. It causes histamine

release with the risk of hypotension if given in a large bolus dose.

100-102. The answers are 100-a, c, d, e, h; 101-b, d, h; 102-f, g, h.

(Schwartz, 7/e, pp 485-507.) The decision to extubate an elderly patient

after major abdominal vascular surgery depends on accurate assessment of

hemodynamic and respiratory factors. Adding to the complexity of this

64 Surgery

particular patient is his past history of cardiac disease and his need for

inotropic support. Ventilatory and blood gas monitoring will determine

whether the patient can be weaned from the respirator. Continuous blood

pressure monitoring via arterial catheterization and pulmonary artery

catheter readings will enable the responsible physicians to assess volume

status and the ongoing need for inotropic support, both critical in the fluid

management of a patient about to be extubated. Continuous ECG monitoring

is essential for this patient because of the high incidence of perioperative

cardiac arrhythmias, particularly atrial fibrillation, following

surgery in which large fluid shifts are anticipated.

Conversely, an otherwise healthy young patient who is discovered to

have a ruptured spleen during emergency laparotomy is unlikely to require

prolonged intubation beyond the time of surgery. Nor is he likely to require

hemodynamic support in the form of pressors or inotropes, since his problem

is one of pure volume loss (blood), which can be met with rapid colloid

and crystalloid administration in the operating room. Consequently,

this patient may be managed with a central venous catheter (or even a

large-bore peripheral catheter, if one can be placed quickly) and ECG and

ventilatory monitoring during his operative procedure. If his hemorrhage is

successfully controlled, early discontinuation of physiologic monitoring

can be anticipated.

Chronically ill patients, such as brain-injured patients in vegetative

states, require nutritional monitoring insofar as they are unable to articulate

their nutritional needs. Caloric expenditure may be calculated to a

modest degree of accuracy using noninvasive methods based on body surface

area, age, and sex (Harris-Benedict equation). More accurate assessment,

particularly appropriate in disease states where metabolic activity is

accelerated, can be made using measurements of oxygen consumption and

carbon dioxide production. A patient who has suffered blunt head trauma

requiring repeated surgeries for intracranial bleeding will likely be monitored

with an intracranial pressure device. Other indications for intracranial

pressure monitoring include subarachnoid hemorrhage, hydrocephalus,

postcraniotomy, and Reye syndrome. ECG monitoring may also be helpful

in this setting, as increasing intracranial pressure may be presaged by

bradycardia.

103-105. The answers are 103-a, b, c, f, j; 104-a, b, c, d, e, f, g, h;

105-i. (Schwartz, 7/e, pp 88-90.) Prothrombin time measures the speed of

coagulation in the extrinsic pathway. A tissue source of procoagulant

Critical Care Answers 65

(thromboplastin) with calcium is added to plasma. The test will detect deficiencies

in factors II, V, VII, X, and fibrinogen and is used to monitor

patients receiving coumarin derivatives. However, even small amounts of

heparin will artificially prolong the clotting time, so that accurate prothrombin

times can only be obtained when the patient has not received

heparin for at least 5 h.

The intrinsic pathway is measured by the partial thromboplastin time.

This test is sensitive for defects in factors VIII, IX, XI, XII, and all the factors

of the extrinsic pathway and is used to monitor the status of patients

on heparin.

The bleeding time assesses the interaction of platelets and the formation

of the platelet plug. Therefore it will pick up deficiencies in both qualitative

and quantitative platelet function. Ingestion of aspirin within 1 wk

of the test will alter the result.

The thrombin time assesses qualitative abnormalities in fibrinogen and

the presence of inhibitors to fibrin polymerization. A standard amount of

fibrin is added to a fixed volume of plasma and clotting time is measured.

66 Surgery

SKIN:WOUNDS,

INFECTIONS, BURNS;

HANDS; PLASTIC SURGERY

Questions

DIRECTIONS: Each item below contains a question or incomplete

statement followed by suggested responses. Select the one best response to

each question.

67

106. Wasting of the intrinsic muscles

of the hand can be expected to

follow injury of the

a. Ulnar nerve

b. Radial nerve

c. Brachial nerve

d. Axillary nerve

e. Thenar and hypothenar nerves

107. Although wide surgical excision

is the traditional treatment for

malignant melanoma, narrow excision

of thin (less than 1 mm deep)

stage I melanomas has been found

to be equally safe and effective

when the margin of resection is as

small as

a. 3 mm

b. 5 mm

c. 1 cm

d. 3 cm

e. 5 cm

108. With regard to wound healing,

which one of the following

statements is correct?

a. Collagen content reaches a maximum

at approximately 1 wk after

injury

b. Monocytes are essential for normal

wound healing

c. Fibroblasts appear in the wound

within 24-36 h after the injury

d. The function of the monocyte in

wound healing is limited to phagocytosis

of bacteria and debris

e. Early in wound healing, type I collagen

is predominant

Terms of Use

Items 109-110

109. While you are on duty in the

emergency room, a 12-year-old

boy arrives with pain and inflammation

over the ball of his left foot

and red streaks extending up the

inner aspect of his leg. He remembers

removing a wood splinter

from the sole of his foot on the previous

day. The most likely infecting

organism is

a. Clostridium perfingens

b. Clostridium tetani

c. Staphylococcus

d. Escherichia coli

e. Streptococcus

110. The appropriate antibiotic to

prescribe while awaiting specific

culture verification is

a. Penicillin

b. Erythromycin

c. Tetracycline

d. Azathioprine

e. Cloxacillin

111. Proper treatment for frostbite

consists of

a. Debridement of the affected part

followed by silver sulfadiazine

dressings

b. Administration of corticosteroids

c. Administration of vasodilators

d. Immersion of the affected part in

water at 40-44°C (104-111.2°F)

e. Rewarming of the affected part at

room temperature

112. The true statement regarding

tendon injuries in the hand is

a. Flexor digitorum superficialis

inserts on the distal phalanx

b. Flexor digitorum profundus inserts

on the middle phalanx

c. The tendons of flexor digitorum

superficialis arise from a common

muscle belly

d. The best results for repair of a

flexor tendon are obtained with

injuries in the fibro-osseous tunnel

(zone 2)

e. The process of healing a tendon

injury involves formation of a

tenoma

113. Which one of the following

cases is considered a cleancontaminated

wound?

a. Open cholecystectomy for cholelithiasis

b. Herniorrhaphy with mesh repair

c. Lumpectomy with axillary node

dissection

d. Appendectomy with walled-off abscess

e. Gunshot wound to the abdomen

with injuries to the small bowel and

sigmoid colon

68 Surgery

114. A 45-year-old woman undergoes

an uneventful laparoscopic

cholecystectomy for which she

receives one dose of cephalosporin.

One week later, she returns to the

emergency room with fever, nausea,

and copious diarrhea and is

subsequently diagnosed with

pseudomembranous colitis. With

respect to this disease, which one of

the following statements is correct?

a. Surgical intervention is frequently

required

b. After appropriate antibiotic therapy,

the relapse rate is less than 5%

c. Tissue culture assay for Clostridium

difficile toxin B is neither sensitive

nor specific; therefore diagnosis

should be based on clinical findings

d. If surgery is performed, a left hemicolectomy

is usually adequate to

treat pseudo-membranous colitis

e. Indications for surgical treatment

include intractable disease, failure

of medical therapy, toxic megacolon,

and colonic perforation

115. A 60-year-old woman presents

with the skin lesion shown

below, which had been present for

10 years. She reported a history of

radiation treatments to that hand

for "eczema." Correct statements

concerning this lesion include

a. It is more malignant than basal cell

carcinoma

b. It occurs more frequently in

brunettes

c. It rarely metastasizes to regional

lymph nodes

d. It should be treated by radiation

therapy

e. It is rarely associated with chronic

sun exposure

Skin:Wounds, Infections, Burns;Hands;Plastic Surgery 69

Items 116-117

116. A 25-year-old man is brought

to the emergency room after sustaining

burns during a fire in his

apartment. He has blistering and

erythema of his face, left upper

extremity, and chest with frank

charring of his right upper extremity.

He is agitated, hypotensive, and

tachycardiac. Which one of the following

statements concerning this

patient's initial wound management

is correct?

a. Topical antibiotics should not be

used, as they will encourage growth

of resistant organisms

b. Early excision of facial and hand

burns is especially important

c. Escharotomy should only be performed

if neurologic impairment is

d. Excision of areas of third-degree or

of deep second-degree burns usually

takes place 3-7 days after

injury

e. Split-thickness skin grafts over the

eschar of third-degree burns should

be performed immediately in order

to prevent fluid loss

117. Which one of the following

statements regarding the above

burn patient is correct?

a. High-dose penicillin should be

administered prophylactically

b. Tetanus prophylaxis is not necessary

if the patient has been immunized

in the previous 3 years

c. This burn can be estimated at 60%

total body surface area using the

"rule of nines"

d. The most sensitive indicator of adequacy

of fluid resuscitation is heart

rate

e. This patient should undergo immediate

intubation for airway protection

and oxygen administration

118. True statements regarding

squamous cell carcinoma of the lip

include

a. The lesion often arises in areas of

persistent hyperkeratosis

b. More than 90% of cases occur on

the upper lip

c. The lesion constitutes 30% of all

cancers of the oral cavity

d. Radiotherapy is considered inappropriate

treatment for these lesions

e. Initially metastases are to the ipsilateral

posterior cervical lymph

nodes

70 Surgery

119. Which of the following statements

regarding carpal tunnel syndrome

is correct?

a. It is rarely secondary to trauma

b. It may be associated with pregnancy

c. It most often causes dysesthesia during

waking hours

d. It is often associated with vascular

compromise

e. Surgical treatment involves release

of the extensor retinaculum

120. Which of the following is

true with regard to wound contraction?

a. It is the primary process affecting

closure of a sutured or stapled surgical

wound

b. Bacterial colonization significantly

slows the process of contraction

c. It may account for a maximum of

50% decrease in the size of a wound

d. It is based on specialized fibroblasts

that contain actin myofilaments

e. The percentage reduction of wound

size is increased with increased

adherency of skin to underlying

tissue

121. Management of leukoplakia

of the oral cavity includes

a. Excisional biopsy of all lesions

b. Application of topical antibiotics

c. Low-dose radiation therapy

d. Ascertaining that dentures fit

properly

e. Application of topical chemotherapeutic

agents

122. An 8-lb infant, born following

uncomplicated labor and delivery,

is noted to have a unilateral

cleft lip and palate. The parents

should be advised that

a. The child almost certainly has

other congenital anomalies

b. Rehabilitation requires adjunctive

speech therapy

c. Lip repair is indicated at 1 year of

age

d. Palate repair is indicated prior to 6

mo of age

e. Cosmetic revisions to the nose

should be performed at the same

time as cleft lip repair

123. A 40-year-old woman undergoes

wide excision of a pigmented

lesion of her thigh. Pathologic

examination reveals malignant

melanoma that is Clark's level IV.

Findings on examination of the

groin are normal. The patient

should be advised that

a. Radiotherapy will be an important

part of subsequent therapy

b. The likelihood of groin node

metastases is remote

c. Immunotherapy is an effective

form of adjunctive treatment for

metastatic malignant melanoma

d. Groin dissection is not indicated

unless and until groin nodes

become palpable

e. Intralesional bacille Calmette-

Guérin (BCG) administration has

been found to aid in local control in

the majority of patients

Skin:Wounds, Infections, Burns;Hands;Plastic Surgery 71

DIRECTIONS: Each group of questions below consists of lettered

options followed by numbered items. For each numbered item, select the

appropriate lettered option(s). Each lettered option may be used once,

more than once, or not at all. Choose exactly the number of options

indicated following each item.

Items 124-127

Match each description with

the correct skin or subcutaneous

lesions.

a. Cystic hygroma

b. Basal cell carcinoma

c. Port-wine stain

d. Strawberry hemangioma

e. Malignant melanoma

f. Squamous cell carcinoma

124. A 56-year-old woman presents

with a small, pigmented

lesion on her forearm, which has

been growing over the last 2 mo.

She is a fair-complected woman

with a history of sun exposure.

(SELECT 3 LESIONS)

125. A 6-mo-old child presents

with a red lesion on the face.

(SELECT 2 LESIONS)

126. Surgical excision is the first

line of therapy. (SELECT 5

LESIONS)

127. Radiation may be useful as

adjuvant therapy. (SELECT 3

LESIONS)

Items 128-131

Match each description with

the correct growth factors or

cytokines.

a. Platelet-derived growth factor

(PDGF)

b. Transforming growth factor

c. Tumor necrosis factor (TNF)

d. Fibroblast growth factor

e. Interleukin 1 (IL-1)

f. Thromboxane A2

128. Platelets are the cell of origin.

(SELECT 3 CHOICES)

129. Macrophages are the cell of

origin. (SELECT 5 CHOICES)

130. They stimulate fibroblast proliferation.

(SELECT 4 CHOICES)

131. They stimulate collagen synthesis.

(SELECT 3 CHOICES)

72 Surgery

SKIN:WOUNDS,

INFECTIONS, BURNS;

HANDS; PLASTIC SURGERY

Answers

106. The answer is a. (Sabiston, 15/e, pp 1479-1485.) The ulnar nerve

innervates 15 of the 20 intrinsic muscles of the hand. The musculocutaneous,

radial, ulnar, and median nerves are all important to hand function.

The musculocutaneous and radial nerves allow forearm supination; the

radial nerve alone innervates the extensor muscles. The median nerve is the

"eye of the hand" because of its extensive contribution to sensory perception;

it also maintains most of the long flexors, the pronators of the forearm,

and the thenar muscles.

107. The answer is c. (Schwartz, 7/e, pp 333, 523-527.) Wide excision of

melanomas, with margins of 3-5 cm beyond the lateral edges of tumor, has

traditionally been considered mandatory. A 5-year prospective multicenter

study of over 600 randomly assigned patients with thin stage I melanomas,

however, showed that local recurrence rates, as well as the subsequent

development of metastatic disease, were not different when margins of 1 cm

or 3 cm were taken, provided that tumor thickness did not exceed 1 mm.

108. The answer is b. (Greenfield 2/e, pp 67-83.) Wound healing is an

overlapping sequence of inflammation, proliferation, and remodeling. The

inflammatory phase is characterized by a rapid influx of neutrophils, followed

in about 2 days by an influx of mononuclear cells. These monocytes

act not only by phagocytosing debris and bacteria, but also by secreting

numerous growth factors including tumor necrosis factor (TNF), transforming

growth factor, platelet-derived growth factor (PDGF), and fibroblast

growth factor, which are essential to normal wound healing.

Angiogenesis and collagen formation take place during the proliferative

phase of wound healing. Fibroblasts, which enter the wound at about day 3,

continue to proliferate with increasing collagen deposition. Throughout the

73

proliferative phase, type III collagen predominates. Collagen content is

maximum at 2-3 wk, at which time the remodeling phase begins. Type III

collagen, which is elastic fibrils, is gradually replaced by rigid fibrils, or type

I collagen, at this time. During remodeling, collagen deposition and degradation

reach a steady state, which may continue for up to 1 year.

109-110. The answers are 109-e, 110-a. (Greenfield, 2/e, p 1970.) The

significant observation in this question is the description of lymphangitic

inflammatory streaking up the inner aspect of the patient's leg. This is

highly suggestive of a streptococcal infection and the presumptive therapy

should be high doses of a bactericidal antibiotic. Penicillin remains the

mainstay of therapy against presumed streptococcal infections. Most streptococcal

cellulitis is adequately treated by penicillin, elevation of the

infected extremity, and attention to the local wound to ascertain adequate

local drainage and absence of any persisting foreign body. However, the

clinician must be alert to the possibility of a more fulminant and life- or

limb-threatening infection by clostridia, microaerophilic streptococcus, or

other potentially synergistic organisms that can produce rapidly progressive

deep infections in fascia of muscle. Smears and cultures of drainage

fluid or aspirates should be taken. Close observation of the wound is essential,

and aggressive debridement in the operating room is mandatory at the

slightest suggestion that fasciitis or myonecrosis may be ensuing.

111. The answer is d. (Greenfield, 2/e, pp 412-414.) Many methods of

treating frostbite have been tried throughout the years. These include massage,

warm-water immersion, or covering the affected area. Rapid warming

by immersion in water slightly above normal body temperature (40-448°C)

is the most effective method; however, because the frostbitten region is

numb and especially vulnerable, it should be protected from trauma or

excessive heat during treatment. Further treatment may include elevation to

minimize edema, administration of antibiotics and tetanus toxoid, and

debridement of necrotic skin as needed.

112. The answer is e. (Schwartz, 7/e, pp 2025-2056.) Each digit has two

long flexors, named superficial and deep according to the relative position of

the muscle bellies. In the fingers each superficial flexor tendon divides

around the corresponding deep tendon to reach its insertion on the base of

74 Surgery

the middle phalanx. The deep flexor tendon continues to its insertion on

the base of the distal phalanx. Only the deep flexors can flex the distal

interphalangeal joint. Since the tendons of the deep flexors share a common

muscle belly, only the superficial flexors can move a finger when the

adjacent fingers are immobilized. These tendons are prevented from bowstringing

across the joints by the flexor retinaculum of the wrists and the

fibroosseous tunnels, which extend from the distal palmar crease to the

middle phalanx. They run within synovial sheaths and are nourished by

vincula tendinum (short mesenteries). The process of healing a tendon

injury involves the formation of a tenoma, which tends to become adherent

to the surrounding sheath. A difficult balance has to be struck between

the desire to prevent adhesions by early mobilization and the risk of rupturing

an unhealed tendon. Verdan has divided the hand into six regions

according to the anatomy surrounding the tendons. Zone 2, sometimes

referred to as "no-man's land," refers to the fibroosseous tunnels. Repair in

this region is fraught with difficulty.

113. The answer is a. (Schwartz, 7/e, pp 130-131.) Surgical wounds can

be divided into three categories based on the amount of bacterial contamination.

Clean wounds are those in which no part of the respiratory, gastrointestinal,

or genitourinary tract is entered. Examples include

herniorrhaphy and breast surgery. Clean-contaminated wounds encompass

those cases in which the above systems are entered, but without evidence

of active infection or gross spillage. Examples include elective cholecystectomy

or elective colon resection with adequate bowel preparation. Contaminated

wounds are those in which there is active infection (perforated

appendicitis with abscess) or gross spillage (gunshot wound with large

or small bowel injuries). While contaminated and clean-contaminated

wounds require perioperative antibiotics, clean wounds need not be

treated with prophylactic antibiotics.

114. The answer is e. (Lipsett, Surgery 116:491-496, 1994.) Pseudomembranous

colitis is a common nosocomial infection most often caused by

Clostridium difficile toxins A and B. Antibiotic use allows overgrowth of C. difficile,

leading to abdominal pain, fever, diarrhea, and increased WBCs. Diagnosis

is confirmed by isolation of C. difficile toxin B via tissue culture assay.

Sensitivity and specificity are quite high (greater than 90%), but may require

Skin:Wounds, Infections, Burns;Hands;Plastic Surgery Answers 75

24-48 h to complete. The vast majority of patients will respond to oral vancomycin

or metronidazole, although 20-30% of patients may relapse.

Because response to antibiotic therapy is high, surgical intervention is infrequently

required (<1%). Indications for surgery include intractable or fulminant

disease, failure of medical therapy, colonic perforation, and toxic

megacolon. Pseudomembranous colitis often involves the entire colon,

despite normal-appearing serosa. Therefore, the procedure of choice is a

subtotal colectomy with ileostomy. Overall mortality of 35-40% is described,

with <20% mortality for those patients undergoing subtotal colectomy.

115. The answer is a. (Schwartz, 7/e, pp 257, 522, 527, 617-621.) Squamous

cell carcinoma occurs in people who have had chronic sun exposure,

chronic ulcers or sinus tracts (draining osteomyelitis), and a history of radiation

or thermal injury (Margolin's ulcer). It is more malignant than basal

cell carcinoma, grows more rapidly, and metastasizes. It occurs more frequently

in blondes and fair-skinned people. A radiation-induced carcinoma,

or one arising in a burn scar, should not be treated with radiation

therapy for fear of further damage.

116. The answer is d. (Schwartz, 7/e, pp 242-244.) Early wound management

is characterized by early excision of areas of devitalized tissue,

with the exception of deep wounds of the palms, soles, genitals, and face.

Staged excision of deep partial-thickness or full-thickness burns occurs

between 3 and 7 days after the injury. There are several proven advantages

to early excision including decreased hospital stay and lower cost. This is

especially true of burns encompassing >30-40% total body surface area. In

conjunction with early excision, topical antimicrobials such as silver sulfadiazine

are extremely important in delaying colonization of the newly

excised or fresh burn wounds. Permanent coverage through split-thickness

skin grafting usually occurs more than 1 wk after injury. Skin autograft

requires a vascular bed and therefore cannot be placed over eschar. Meticulous

attention to deep circumferential burns is crucial in the management

of burn patients. Progressive tissue edema may lead to progressive vascular

and neurologic compromise. Because the blood supply is the initial system

affected, frequent assessment of flow is vital, with longitudinal escharotomy

performed at the first sign of vascular compromise. A low threshold

should be maintained in performing an escharotomy in the setting of

severely burned limbs.

76 Surgery

117. The answer is e. (Schwartz, 7/e, pp 228-232, 234-238.) Aggressive

evaluation and treatment of burn victims has led to increased survival of

the 2 million patients treated for burns each year in the United States. A

systematic approach to the patient with attention to airway/vascular access

and aggressive fluid resuscitation has proved essential. In the patient with

obvious facial burns who is hemodynamically unstable, airway access is the

first priority. Fluid resuscitation is initiated using the Parkland formula,

with urine output of 0.5-1.0 mL/kg/h being the most sensitive indicator of

the adequacy of resuscitation. The extent of the burn can be roughly estimated

using the "rule of nines," in which the head and the upper extremities

are each 9% of the total body surface area (TBSA) and the anterior

trunk, posterior trunk, and the lower extremities are each 18% of the

TBSA. The neck encompasses 1% of the TBSA. This patient has burns of

roughly 40% TBSA (face 4.5%, upper extremities 18%, and anterior trunk

18%). Tetanus prophylaxis is indicated in all patients who have not been

immunized within 1 year; prophylactic intravenous antibiotics are not

indicated because they have not been shown to be of benefit in decreasing

early cellulitic infections. Conversely, they have been shown to lead to

increased complications secondary to resistant gram-negative organisms.

118. The answer is a. (Schwartz, 7/e, pp 629, 631.) Squamous cell carcinoma

of the lip is the most common malignant tumor of the lip and constitutes

15% of all malignancies of the oral cavity. Basal cell carcinomas do

occur on the lip, but much less frequently. There is a strong association

between squamous cell tumors of the lip and sun exposure. Therefore,

these lesions are more common in the southern United States and in occupational

groups who work out of doors. Because of its greater sun exposure,

the lower lip is the site of more than 90% of such lesions. Persistent

hyperkeratosis precedes 35-40% of these lesions. The incidence of metastases

increases with the size of the lesion, and spread is usually via lymphatics

to the ipsilateral submental node. Contralateral nodal metastases

are rare unless the lesion crosses the midline. Approximately 10-15% of all

patients have metastases at the time of diagnosis. These lip tumors are very

responsive to radiotherapy, which works well for small to medium-sized

lesions. Large lesions treated with radiotherapy usually require surgical

reconstruction. Radiotherapy should not be used in patients who will have

ongoing sun exposure to the area because radiation therapy sensitizes the

tissues to solar trauma.

Skin:Wounds, Infections, Burns;Hands;Plastic Surgery Answers 77

119. The answer is b. (Schwartz, 7/e, pp 2063-2070.) Signs and symptoms

of carpal tunnel syndrome are related to the distribution of the

median nerve. This nerve, which passes through the carpal tunnel is the

wrist with the finger flexor tendons, may suffer compression from fibrous

scarring or malalignment following a fracture of the wrist. Nerve compression

may also occur in patients with rheumatoid arthritis who develop

flexor tenosynovitis. In women, the syndrome frequently first appears during

pregnancy and recurs during the premenstrual phase of subsequent

menstrual cycles. In these cases, symptoms are presumably the result of the

effects of fluid retention and pressure on the median nerve owing to tissue

swelling. In many instances, symptoms are limited to nocturnal pain and

paresthesias. If conservative treatment of carpal tunnel syndrome is unsuccessful,

surgical treatment may be required. Open and endoscopic techniques

have been employed, both of which release adhesions of the median

nerve and divide the transverse carpal ligament. The extensor retinaculum

is located on the dorsal aspect of the wrist and contains the six compartments

of extensor tendons.

120. The answer is d. (Schwartz, 7/e, pp 270-277.) While epithelialization

is responsible for the healing of a closed incision, wound contraction is the

primary method of closure in open wounds. During this process, the skin

surrounding the wound is pulled over the wound surface and may account

for up to a 90% reduction in the size of an open wound. In areas of greater

adherence of skin to underlying tissue, the ability of contraction to close the

wound is hindered due to the decreased mobility of the skin. Therefore, in

areas of tight skin adherence such as the leg, contraction may only account

for 30-40% reduction in wound size. Fibroblasts in the open wound, which

predominate during the proliferative phase, contain increasing numbers of

actin microfilaments, thereby becoming myofibroblasts. These specialized

fibroblasts are felt to be responsible for wound contraction either through

intrinsic cellular contraction or attachment to collagen strands. Bacterial colonization

does not harm the process of wound contraction and surgical

wound healing. While wound infection is often difficult to diagnose in open

wounds, it is generally accepted that bacterial counts of 1 million bacteria per

gram of tissue are deleterious to wound closure.

121. The answer is d. (Schwartz, 7/e, pp 604, 610.) White patches in the

oral cavity (leukoplakia) sometimes are incorrectly interpreted as a pre-

78 Surgery

malignant condition. Microscopic examination of leukoplakia may in fact

reveal hyperplasia, keratosis, or dyskeratosis, of which the last finding is the

most serious because of its association with malignancy. Only about 5% of

patients with leukoplakia develop cancer. A suggested treatment protocol

for patients with thin lesions advocates a program of strict oral hygiene and

avoidance of alcohol and tobacco. Biopsy is reserved only for those with

thick lesions (since carcinoma in situ may be present). Radiation therapy is

contraindicated. Approximately 50% of all oral cancers occur in patients

who have associated areas of hyperkeratosis and dyskeratosis. Chronic irritation,

as may occur with poorly fitting dentures, may result in leukoplakia.

122. The answer is b. (Schwartz, 7/e, pp 2106-2110.) Clefts of the lip

and palate occur relatively frequently (1 in 750 live births); they may be

unilateral or bilateral and can vary from a small notch to a complete cleft of

the lip and palate. Most clefts occur as isolated anomalies, but occasionally

they are associated with neurologic, orthopedic, or cardiac anomalies. A

frequently recommended protocol for management is lip repair in the first

3 mo of life and palate repair at 12 to 18 mo. Other cosmetic procedures

can be performed late in childhood and adolescence. Palate repair after 2

years of age is associated with a high incidence of speech impairment, often

requiring speech therapy; repair in the early months of life can lead to a

hazardous loss of blood that is poorly tolerated by the infant. Repair of the

lip usually should be accomplished as soon as the infant is sufficiently stabilized

to tolerate anesthesia with reasonable safety. Ten to twelve weeks is

often recommended as the time for lip repair. At this age, the affected baby

usually can be converted to dropper or cup feedings in the postoperative

period, which thereby facilitates healing of the lip by reducing the need for

suckling with the freshly wounded tissues.

123. The answer is d. (Greenfield, 2/e, pp 2231-2242.) The survival of

patients with malignant melanoma correlates with the depth of invasion

(Clark) and the thickness of the lesion (Breslow). It is widely held that

patients with thin lesions (<0.76 mm) and Clark level I and II lesions are

adequately managed by wide local excision. The incidence of nodal metastases

rises with increasing Clark level of invasion such that a level IV lesion

has a 30-50% incidence of nodal metastases. The assumption that removal

of microscopic foci of disease is beneficial, in conjunction with retrospective

data indicating improved survival in patients who have undergone

Skin:Wounds, Infections, Burns;Hands;Plastic Surgery Answers 79

removal of clinically negative but pathologically positive nodes, has led to

the widely held belief that prophylactic node dissections are indicated for

melanoma. Prospective data has challenged this concept. Veronesi and Sim

have found that patients undergoing prophylactic node dissections survived

no longer than those who were followed closely and underwent node

dissections only after nodes became palpable. The subject remains controversial,

and further study and follow-up are necessary. Immunotherapy has

not been successful in controlling widespread metastatic melanoma even

when added to chemotherapy. Intralesional administration of BCG has

been demonstrated to control local skin lesions in only 20% of patients.

Dinitrochlorobenzene (DNCB) can also be used.

124-127. The answers are 124-b, e, f; 125-c, d; 126-a, b, c, e, f;

127-b, e, f. (Greenfield, 2/e, pp 2231-2245.) Cutaneous neoplasms are

extremely prevalent in the United States, with basal cell and squamous cell

carcinoma being the most common. Patients who are at particular risk for

malignant neoplasms are those with fair complexion and frequent sun

exposure. Other risk factors for basal and squamous cell carcinomas

include radiation damage, chronic wounds, and scar tissue. Surgical excision

is the treatment of choice of all malignant cutaneous neoplasms. Radiation

therapy may be useful for palliation of metastatic melanoma and may

be considered as adjuvant therapy for squamous cell carcinoma and aggressive

or invasive basal cell carcinoma. The pediatric population may suffer

from multiple cutaneous lesions, including port-wine stains and strawberry

hemangiomas. Both are capillary hemangiomas, but with very different

clinical courses. Port-wine stains are present from birth and do not

regress; therefore, surgical excision is a treatment option in small lesions.

Other treatment options include laser cauterization or tattooing. Strawberry

hemangiomas typically grow rapidly over 6-12 mo, but 90% regress

spontaneously; therefore, commonly no intervention is required. For particularly

large or rapidly growing lesions, excision, laser cauterization, or

steroids may be considered. Cystic hygromas are masses of lymphatic vessels

typically present in the head and neck region, usually apparent at

birth. They are easily diagnosed with ultrasonography and are treated with

surgical excision.

128-131. The answers are 128-a, b, f; 129-a, b, c, d, e; 130-b, c, d,

e; 131-b, c, e. (Greenfield, 2/e, pp 108-126.) Numerous cytokines or

80 Surgery

growth factors are liberated from various cells at the time of injury. The

process of wound healing requires that these factors act in an orchestrated

manner. Platelets release ADP, thromboxane A2, transforming growth factor,

and platelet-derived growth factor within 1 h of injury. When

macrophages become the predominant cell (at 2-3 days), numerous additional

cytokines are released, including IL-1, fibroblast growth factor, TNF,

transforming growth factor, and PDGF, among others. Integral to adequate

wound healing is fibroblast proliferation and collagen synthesis. Stimulants

of fibroblast proliferation include TNF, IL-1, fibroblast growth factor, transforming

growth factor, epithelial growth factor, and plasminogen activator

inhibitor. Collagen synthesis is then initiated and progresses during the

proliferative phase of wound healing upon stimulation by IL-1, TNF, and

transforming growth factor. Excessive or unopposed release of cytokines is

thought to be responsible in various pathologic states of wound healing,

such as pulmonary fibrosis or hepatic cirrhosis, and can lead to failure of

multiple organ systems.

Skin:Wounds, Infections, Burns;Hands;Plastic Surgery Answers 81

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TRAUMA AND SHOCK

Questions

DIRECTIONS: Each item below contains a question or incomplete

statement followed by suggested responses. Select the one best response to

each question.

83

132. A teenage boy falls from his

bicycle and is run over by a truck.

On arrival in the emergency room,

he is awake and alert and appears

frightened but in no distress. The

chest radiograph suggests an airfluid

level in the left lower lung

field and the nasogastric tube

seems to coil upward into the left

chest. The next best step in management

a. Placement of a left chest tube

b. Immediate thoracotomy

c. Immediate celiotomy

d. Esophagogastroscopy

e. Removal and replacement of the

nasogastric tube; diagnostic peritoneal

lavage

133. Which of the following conditions

is most likely to follow

a compression-type abdominal injury?

a. Renal vascular injury

b. Superior mesenteric thrombosis

c. Mesenteric vascular injury

d. Avulsion of the splenic pedicle

e. Diaphragmatic hernia

134. A 65-year-old man who

smokes cigarettes and has chronic

obstructive pulmonary disease falls

and fractures the 7th, 8th, and 9th

ribs in the left anterolateral chest.

Chest x-ray is otherwise normal.

Appropriate treatment might include

a. Strapping the chest with adhesive

tape

b. Immobilization with sandbags

c. Tube thoracostomy

d. Peritoneal lavage

e. Surgical fixation of the fractured

135. Blunt trauma to the abdomen

most commonly injures which of

the following organs?

a. Liver

b. Kidney

c. Spleen

d. Intestine

e. Pancreas

Terms of Use

136. Ligation of injured major

peripheral veins is rarely preferable

to repair, but may be justified for

which reason?

a. In severe popliteal vascular injuries,

venous ligation leads to a decreased

amputation rate following successful

arterial reconstruction when

compared with combined arterial

and venous repair

b. Venous ligation leads to a decreased

incidence of chronic venous insufficiency

when compared with venous

repair

c. Venous ligation leads to a decreased

operative time in patients with

multiple injuries or severe trauma

when compared with venous repair

d. In the presence of extensive associated

soft tissue injury, venous return

is already sufficiently impaired to

render venous repair pointless

e. Even though ligated veins thrombose,

they often recanalize

137. A 27-year-old man sustains a

single gunshot wound to the left

thigh. In the emergency room he is

noted to have a large hematoma of

his medial thigh. He complains of

paresthesias in his foot. On examination

there are weak pulses palpable

distal to the injury and the

patient is unable to move his foot.

The appropriate initial management

of this patient would be

a. Angiography

b. Immediate exploration and repair

c. Fasciotomy of anterior compartment

d. Observation for resolution of spasm

e. Local wound exploration

Items 138-139

A 25-year-old woman arrives

in the emergency room following

an automobile accident. She is

acutely dyspneic with a respiratory

rate of 60 breaths/min. Breath

sounds are markedly diminished

on the right side.

138. The first step in managing

the patient should be to

a. Take a chest x-ray

b. Draw arterial blood for blood gas

determination

c. Decompress the right pleural space

d. Perform pericardiocentesis

e. Administer intravenous fluids

84 Surgery

139. A chest x-ray of this woman

beforetherapywouldprobablyreveal

a. Air in the right pleural space

b. Shifting of the mediastinum toward

the right

c. Shifting of the trachea toward the

right

d. Dilation of the intrathoracic vena

cava

e. Hyperinflation of the left lung

140. Among the physiologic responses

to acute injury is

a. Increased secretion of insulin

b. Increased secretion of thyroxine

c. Decreased secretion of vasopressin

(ADH)

d. Decreased secretion of glucagon

e. Decreased secretion of aldosterone

141. In a stable patient, the management

of a complete transection

of the common bile duct distal to

the insertion of the cystic duct

would be optimally performed

with a

a. Choledochoduodenostomy

b. Loop choledochojejunostomy

c. Primary end-to-end anastomosis of

the transected bile duct

d. Roux-en-Y choledochojejunostomy

e. Bridging of the injury with a T tube

142. Nonoperative management of

penetrating neck injuries has been

advocatedasanalternative tomandatory

exploration in asymptomatic

patients. Which of the following

findings would constitute a relative,

rather than an absolute, indication

for formal neck exploration?

a. Expanding hematoma

b. Dysphagia

c. Dysphonia

d. Pneumothorax

e. Hemoptysis

143. Following blunt abdominal

trauma, a 12-year-old girl develops

upper abdominal pain, nausea, and

vomiting. An upper gastrointestinal

series reveals a total obstruction

of the duodenum with a "coiled

spring" appearance in the second

and third portions. Appropriate

management is

a. Gastrojejunostomy

b. Nasogastric suction and observation

c. Duodenal resection

d. TPN to increase the size of the

retroperitoneal fat pad

e. Duodenojejunostomy

144. Following traumatic peripheral

nerve transection, regrowth

usually occurs at which of the following

rates?

a. 0.1 mm per day

b. 1 mm per day

c. 5 mm per day

d. 1 cm per day

e. None of the above

Trauma and Shock 85

Items 145-147

A 28-year-old man is brought

to the emergency room for a severe

head injury after a fall. Initially

lethargic, he becomes comatose and

does not move his right side. His

left pupil is dilated and responds

only sluggishly.

145. The most common initial

manifestation of increasing intracranial

pressure in the victim of

head trauma is

a. Change in level of consciousness

b. Ipsilateral (side of hemorrhage)

pupillary dilation

c. Contralateral pupillary dilation

d. Hemiparesis

e. Hypertension

146. Initial emergency reduction

of intracranial pressure is most

rapidly accomplished by

a. Saline-furosemide (Lasix) infusion

b. Urea infusion

c. Mannitol infusion

d. Intravenous dexamethasone (Decadron)

e. Hyperventilation

147. In the patient described,

compression of the affected nerve is

produced by

a. Infection within the cavernous sinus

b. Herniation of the uncal process of

the temporal lobe

c. Laceration of the corpus callosum

by the falx cerebri

d. Occult damage to the superior cervical

ganglion

e. Cerebellar hypoxia

148. A 31-year-old man is brought

to the emergency room following

an automobile accident in which

his chest struck the steering wheel.

Examination reveals stable vital

signs, but the patient exhibits multiple

palpable rib fractures and

paradoxical movement of the right

side of the chest. Chest x-ray shows

no evidence of pneumothorax or

hemothorax, but a large pulmonary

contusion is developing. Proper

treatment would consist of which

of the following?

a. Tracheostomy, mechanical ventilation,

and positive end-expiratory

pressure

b. Stabilization of the chest wall with

sandbags

c. Stabilization with towel clips

d. Immediate operative stabilization

e. No treatment unless signs of respiratory

distress develop

86 Surgery

149. A 30-year-old man is stabbed

in the arm. There is no evidence of

vascular injury, but he cannot flex

his three radial digits. He has injured

the

a. Flexor pollicis longus and flexor

digitus medius tendons

b. Radial nerve

c. Median nerve

d. Thenar and digital nerves at the

wrist

e. Ulnar nerve

150. Following a 2-h fire-fighting

episode, a 36-year-old fireman begins

complaining of a throbbing

headache, nausea, dizziness, and

visual disturbances. He is taken to

the emergency room where his

carboxyhemoglobin (COHb) level

is found to be 31%. Appropriate

treatment would be to

a. Begin an immediate exchange

transfusion

b. Transfer the patient to a hyperbaric

oxygen chamber

c. Begin bicarbonate infusion and give

250 mg acetazolamide (Diamox)

intravenously

d. Administer 100% oxygen by mask

e. Perform flexible bronchoscopy

with further therapy determined by

findings

151. An elderly pedestrian collides

with a bicycle-riding pizza

delivery man and suffers a unilateral

fracture of his pelvis through

the obturator foramen. You would

manage this injury by

a. External pelvic fixation

b. Angiographic visualization of the

obturator artery with surgical

exploration if the artery is injured

or constricted

c. Direct surgical approach with internal

fixation of the ischial ramus

d. Short-term bed rest with gradual

ambulation as pain allows after 3

days

e. Hip spica

152. Regarding high-voltage electrical

burns to an extremity

a. Injuries are generally more superficial

than those of thermal burns

b. Intravenous fluid replacement is

based on the percentage of body

surface area burned

c. Antibiotic prophylaxis is not required

d. Evaluation for fracture of the other

extremities and visceral injury is

indicated

e. Cardiac conduction abnormalities

are unlikely

Trauma and Shock 87

153. Which of the following fractures

or dislocations of the extremities

induced by blunt trauma is

associated with significant vascular

injuries?

a. Knee dislocation

b. Closed posterior elbow dislocation

c. Midclavicular fracture

d. Supracondylar femur fracture

e. Tibial plateau fracture

154. A 23-year-old previously

healthy man presents to the emergency

room after sustaining a single

gunshot wound to the left chest.

The entrance wound is 3 cm inferior

to the nipple and the exit

wound is just below the scapula. A

chest tube is placed that drains 400

mL of blood and continues to drain

50-75 mL/h during the initial

resuscitation. Initial blood pressure

of 70/0 mm Hg responds to 2 L

crystalloid and is now 100/70 mm

Hg. Abdominal examination is

unremarkable. Chest x-ray reveals

a reexpanded lung and no free air

under the diaphragm. The next

management step should be

a. Admission and observation

b. Peritoneal lavage

c. Exploratory thoracotomy

d. Exploratory celiotomy

e. Local wound exploration

155. A patient is brought to the

emergency room after a motor

vehicle accident. He is unconscious

and has a deep scalp laceration and

one dilated pupil. His heart rate is

120 beats/min, blood pressure is

80/40 mm Hg, and respiratory rate

is 35 breaths/min. Despite rapid

administration of 2 L normal

saline, the patient's vital signs do

not change significantly. The injury

likely to explain this patient's

hypotension is

a. Epidural hematoma

b. Subdural hematoma

c. Intraparenchymal brain hemorrhage

d. Basilar skull fracture

e. None of the above

156. When operating to repair

civilian colon injuries

a. A colostomy should be performed

for colonic injury in the presence of

gross fecal contamination

b. The presence of shock on admission

or more than two associated

intraabdominal injuries is an

absolute contraindication to primary

colonic repair

c. Distal sigmoidal injuries should not

be repaired primarily

d. Right-sided colonic wounds should

not be repaired primarily

e. Administration of intravenous

antibiotics with aerobic and anaerobic

coverage has not been shown

to decrease the incidence of wound

infections after repair of colonic

injuries

88 Surgery

157. A 34-year-old prostitute with a history of long-term intravenous drug

use is admitted with a 48-h history of pain in her left arm. Physical examination

is remarkable for crepitus surrounding needle track marks in the

antecubital space with a serous exudate. The plain x-ray of the arm is

shown below. Which of the following organisms is most likely to be

responsible for this condition?

Trauma and Shock 89

a. Anaerobic streptococcus

b. Staphylococcus aureus

c. Pseudomonas aeruginosa

d. Clostridium perfringens

e. Escherichia coli

158. Regarding myocardial contusion

from blunt chest trauma,

which of the following statements

is correct?

a. Elevated cardiac isoenzyme levels

sensitively identify patients at risk

for life-threatening arrhythmias

b. The majority of patients have

abnormalities on the initial ECG

post injury

c. First-pass radionuclide angiography

(RNA) and echocardiography

are considered the "gold standard"

for diagnosis

d. RNA and echocardiography are

good predictors of subsequent cardiac

complications such as arrhythmias

and pump failure

e. All patients diagnosed with myocardial

contusion should be monitored

in an intensive care unit

setting for 72 h

159. Protein metabolism after

trauma is characterized by

a. Decreased liver gluconeogenesis

b. Inhibition of skeletal muscle breakdown

by interleukin 1 and tumor

necrosis factor (TNF, cachectin)

c. Decreased urinary nitrogen loss

d. Hepatic synthesis of acute-phase

reactants

e. Decreased glutamine consumption

by fibroblasts, lymphocytes, and

intestinal epithelial cells

160. A 36-year-old man sustains a

gunshot wound to the left buttock.

He is hemodynamically stable.

There is no exit wound, and an xray

of the abdomen shows the bullet

to be located in the right lower

quadrant. Correct management of a

suspected rectal injury would

include

a. Barium studies of the colon and

rectum

b. Barium studies of the bullet track

c. Endoscopy of the bullet track

d. Angiography

e. Sigmoidoscopy in the emergency

161. Correct statements regarding

blunt trauma to the liver include

which of the following?

a. Hepatic artery ligation for control

of bleeding is associated with

decreased morbidity and mortality

b. The incidence of intraabdominal

infections is significantly lower in

patients with abdominal drains

c. Intracaval shunting has dramatically

improved survival among

patients with hepatic vein injuries

d. Nonanatomic hepatic debridement,

with removal of the injured

fragments only, is preferable to

resection along anatomic planes

e. Major hepatic lacerations that are

sutured closed will result in intrahepatic

hematomas, hemobilia, and

bile fistulas

90 Surgery

162. If injury to a major artery in

an extremity is suspected, surgical

exploration should be carried out

regardless of the presence of palpable

pulses distal to the injury. The

rationale is that the presence of palpable

distal pulses does not reliably

exclude

a. Significant arterial injury

b. Significant injury to adjacent motor

nerve trunks

c. Significant injury to adjacent long

d. Significant injury to adjacent veins

e. Subsequent development of a compartment

syndrome and the need

for fasciotomy

163. The response to shock

includes which of the following

metabolic effects?

a. Increase in sodium and water

excretion

b. Increase in renal perfusion

c. Decrease in cortisol levels

d. Hyperkalemia

e. Hypoglycemia

164. Appropriate treatment for an

acute stable hematoma of the pinna

of the ear includes which of the following

measures?

a. Ice packs and prophylactic antibiotics

b. Excision of the hematoma

c. Needle aspiration

d. Incision, drainage, and pressure

bandage

e. Observation alone

165. Animal and clinical studies

have shown that administration of

lactated Ringer's solution to patients

with hypovolemic shock may

a. Increase serum lactate concentration

b. Impair liver function

c. Improve hemodynamics by alleviating

the deficit in the interstitial

fluid compartment

d. Increase metabolic acidosis

e. Increase the need for blood transfusion

Items 166-167

An 18-year-old high school

football player is kicked in the left

flank. Three hours later he develops

hematuria. His vital signs are

stable.

166. The diagnostic tests performed

reveal extravasation of contrast

into the renal parenchyma.

Treatment should consist of

a. Resumption of normal daily activity

excluding sports

b. Exploration and suture of the laceration

c. Exploration and wedge resection of

the left kidney

d. Nephrostomy

e. Antibiotics and serial monitoring of

blood count and vital signs

Trauma and Shock 91

167. Initial diagnostic tests in the

emergency room should include

which of the following?

a. Retrograde urethrography

b. Retrograde cystography

c. Arteriography

d. Intravenous pyelogram

e. Diagnostic peritoneal lavage

168. True statements concerning

penetrating pancreatic trauma

include

a. Most injuries do not involve adjacent

organs

b. Management of a ductal injury to

the left of the mesenteric vessels is

Roux-en-Y pancreaticojejunostomy

c. Management of a ductal injury in

the head of the pancreas is pancreaticoduodenectomy

d. Small peripancreatic hematomas

need not be explored to search for

pancreatic injury

e. The major cause of death is exsanguination

from associated vascular

injuries

169. Rapid fluid resuscitation of

the hypovolemic patient after abdominal

trauma is significantly enhanced

by which of the following?

a. Placement of long 18-gauge subclavian

vein catheters

b. Placement of percutaneous femoral

vein catheters

c. Bilateral saphenous vein cutdowns

d. Placement of short, large-bore percutaneous

peripheral intravenous

catheters

e. Infusion of cold whole blood

170. Use of the pneumatic antishock

garment (PASG)

a. Elevates blood pressure by an

"autotransfusion" effect, with augmentation

of venous return and

cardiac output

b. Is not recommended for control of

persistent bleeding in the setting of

severe pelvic fracture

c. Increases peripheral vascular resistance

d. Expedites assessment of lower

body injuries in the trauma patient

e. Should be terminated by means of

prompt deflation as soon as the

trauma patient reaches the emergency

department

92 Surgery

171. Which of the following situations

would be an indication for

performance of a thoracotomy in

the emergency room?

a. Massive hemothorax following

blunt trauma to the chest

b. Blunt trauma to multiple organ systems

with obtainable vital signs in

the field but none on arrival in the

emergency room

c. Rapidly deteriorating patient with

cardiac tamponade from penetrating

thoracic trauma

d. Penetrating thoracic trauma and no

signs of life in the field

e. Penetrating abdominal trauma and

no signs of life in the field

172. A 22-year-old man sustains a

gunshot wound to the abdomen. At

exploration, an apparently solitary

distal small-bowel injury is treated

with resection and primary anastomosis.

On postoperative day 7,

small-bowel fluid drains through

the operative incision. The fascia

remains intact. The fistula output is

300 mL/day and there is no evidence

of intraabdominal sepsis.

Correct treatment includes

a. Early reoperation to close the fistula

tract

b. Broad-spectrum antibiotics

c. Total parenteral nutrition

d. Somatostatin to lower fistula output

e. Loperamide to inhibit gut motility

Trauma and Shock 93

173. A 26-year-old man sustains a

gunshot wound to the left thigh.

Exploration reveals that a 5-cm

portion of superficial femoral artery

is destroyed. Appropriate management

includes

a. Debridement and end-to-end anastomosis

b. Debridement and repair with an

interposition prosthetic graft

c. Debridement and repair with an

interposition arterial graft

d. Debridement and repair with an

interposition vein graft

e. Ligation and observation

174. The patient illustrated on the

chest x-ray film and contrast study

on the following page was hospitalized

after a car collision in which

he suffered blunt trauma to the

abdomen. He sustained several left

rib fractures, but was hemodynamically

stable. True statements about

the injury demonstrated in the

films include

a. The injury depicted is the most frequent

organ injury in the setting of

blunt trauma to the abdomen

b. Delayed operative repair is indicated

after the patient's rib fractures

are allowed to stabilize

c. Surgical treatment of this injury is

indicated during this hospitalization

d. Early repair of this injury is preferably

accomplished through a left

posterolateral thoracotomy

e. If this injury is incidentally discovered

during a surgical exploration,

it should not be repaired

94 Surgery

95

DIRECTIONS: Each group of questions below consists of lettered

options followed by numbered items. For each numbered item, select the

appropriate lettered option(s). Each lettered option may be used once,

more than once, or not at all. Choose exactly the number of options

indicated following each item.

Items 175-177

For each diagnostic technique

listed below, select the injuries it

reliably identifies.

a. Significant intraperitoneal bleeding

b. Injury of a retroperitoneal organ

c. Retroperitoneal (pelvic and visceral)

vascular extravasation

d. Minor lacerations of liver and

spleen

e. Subcapsular hematomas of liver

and spleen

f. Injury of the small intestine

g. Diaphragmatic injury

175. Diagnostic peritoneal lavage

(SELECT 2 INJURIES)

176. Abdominal computed tomography

(SELECT 3 INJURIES)

177. Visceral angiography

(SELECT 1 INJURY)

Items 178-180

For each scenario listed below,

choose the abdominal organs most

likely to be injured.

a. Diaphragm

b. Liver

c. Spleen

d. Small intestine

e. Large intestine

f. Kidneys

g. Stomach

h. Pancreas

i. Bladder

j. Great vessels (aorta/vena cava)

178. A motorist decelerates

rapidly after striking a stalled vehicle.

He is traveling at 55 mi/h at the

time of impact. He is wearing a seat

belt and his car is equipped with an

air bag. (SELECT 3 ORGANS)

179. A man is shot with a highvelocity

bullet that traverses his

mid-abdomen at the level of the

umbilicus. (SELECT 3 ORGANS)

180. An unsuspecting victim is

struck forcefully in the upper

abdomen by a mugger with a baseball

bat. (SELECT 4 ORGANS)

96 Surgery

Items 181-185

For each of the immediately

life-threatening injuries of the chest

listed below, select the proper intervention.

a. Endotracheal intubation

b. Cricothyroidotomy

c. Subxiphoid window

d. Tube thoracostomy

e. Occlusive dressing

181. Laryngeal obstruction (SELECT

1 INTERVENTION)

182. Open pneumothorax (SELECT

1 INTERVENTION)

183. Flail chest (SELECT 1 INTERVENTION)

184. Tension pneumothorax (SELECT

1 INTERVENTION)

185. Pericardial tamponade (SELECT

1 INTERVENTION)

Trauma and Shock 97

98

TRAUMA AND SHOCK

Answers

132. The answer is c. (Greenfield, 2/e, pp 284, 337.) The finding of an airfluid

level in the left lower chest with a nasogastric tube entering it after

blunt trauma to the abdomen is diagnostic of diaphragmatic rupture with

gastric herniation into the chest. This lesion needs to be fixed immediately.

With continuing negative pressure in the chest, each breath sucks more of

the abdominal contents into the chest and increases the likelihood of vascular

compromise of the herniated viscera. While the diaphragm is easily

fixed from the left chest, this injury should be approached from the

abdomen. The possibility of injury below the diaphragm after sufficient

blunt injury to rupture the diaphragm mandates examination of the

intraabdominal solid and hollow viscera; adequate exposure of the

diaphragm to allow secure repair is possible from this approach.

133. The answer is e. (Sabiston, 15/e, pp 308-312.) In the rapiddeceleration

injury associated with automobile crashes, the abdominal viscera

tend to continue moving anteriorly after the body wall has been

stopped. These organs exert great stress upon the structures anchoring

them to the retroperitoneum. Intestinal loops stretch and may tear their

mesenteric attachments, injuring and thrombosing the superior mesenteric

artery; kidneys and spleen may similarly shear their vascular pedicles. In

these injuries, however, ordinarily the intraabdominal pressure does not

rise excessively and diaphragmatic hernia is not likely. Diaphragmatic hernia

is primarily associated with compression-type abdominal or thoracic

injuries that increase intraabdominal or intrathoracic pressure sufficiently

to tear the central portion of the diaphragm.

134. The answer is d. (Sabiston, 15/e, pp 307-309.) The preeminent concern

in treatment of rib fractures is the prevention of pulmonary complications

(atelectasis and pneumonia), particularly for patients with preexisting

pulmonary disease, who are in danger of progressing to respiratory failure.

Attempts to relieve pain by immobilization or splinting, such as strapping

the chest, merely compound the problem of inadequate ventilation. Tube

thoracostomy is indicated only if pneumothorax is diagnosed. Mild pain

may be controlled with oral analgesics, and patients with minor fracture

injuries, if they can be closely monitored, may be managed at home with

appropriate instructions for coughing and deep breathing. Patients with

significant fractures or severe pain should be hospitalized. Rib fractures

in the elderly are particularly treacherous. Intercostal nerve blocks often

provide prolonged periods of pain relief and, together with appropriate

pulmonary physiotherapy, will inhibit development of respiratory complications.

Rib fractures are often associated with either intrathoracic or

intraabdominal injuries. In particular, fractures of the left chest wall should

arouse suspicion of splenic trauma. In equivocal cases, peritoneal lavage

will often be diagnostic. Rib fractures heal spontaneously, without need for

surgical fixation.

135. The answer is c. (Sabiston, 15/e, pp 312-325.) The diagnosis of

injuries resulting from blunt abdominal trauma is difficult; injuries are

often masked by associated injuries. Thus, trauma to the head or chest,

together with fractures, frequently conceals intraabdominal injury. Apparently

trivial injuries may rupture abdominal viscera in spite of the protection

offered by the rib cage. The structures most likely to be damaged in

blunt abdominal trauma are, in order of frequency, the spleen, kidney,

intestine, liver, abdominal wall, mesentery, pancreas, and diaphragm.

Abdominal paracentesis is a rapid, sensitive diagnostic test for patients

with suspected intraabdominal injury and may be extremely helpful in the

management of patients with associated head, thoracic, or pelvic trauma in

whom signs and symptoms of the abdominal injuries may be masked or

overlooked. Abdominal CT scans, which should be done promptly and

rapidly, are being used more frequently to evaluate these injuries.

136. The answer is c. (Sabiston, 15/e, p 333.) In the past, ligation rather

than repair of large veins in the extremities has been advocated in patients

with multiple injuries or severe trauma. Venous repair adds to the operative

time, often results in thrombosis and occlusion, and was thought to lead to

an increased incidence of pulmonary embolization. Recent studies, including

reviews of the Viet Nam Vascular Registry, indicate that the risk of pulmonary

embolization is not increased with repair and that vein repair, in

conjunction with arterial repair, increases limb salvage, particularly in

popliteal injuries. Venous repair may also be necessary in the presence of

Trauma and Shock Answers 99

extensive soft tissue trauma and an already severely compromised venous

return. Long-term follow-up reveals that the sequelae of chronic venous

insufficiency develop with increasing frequency in those patients who have

had ligations of lower-extremity veins. Morbidity from chronic deep

venous occlusion may be diminished even in those patients who develop

thrombosis following repair, because recanalization often occurs. Ligated

veins do not recanalize. For these reasons, it is currently recommended

that large veins be repaired whenever clinically feasible.

137. The answer is b. (Sabiston, 15/e, pp 332-333.) The five P's of arterial

injury include Pain, Paresthesias, Pallor, Pulselessness, and Paralysis.

In the extremities the tissues most sensitive to anoxia are the peripheral

nerves and striated muscle. The early developments of paresthesias and

paralysis are signals that there is significant ischemia present and immediate

exploration and repair are warranted. The presence of palpable pulses

does not exclude an arterial injury because this presence may represent a

transmitted pulsation through a blood clot. When severe ischemia is

present, the repair must be completed within 6-8 h to prevent irreversible

muscle ischemia and loss of limb function. Delay to obtain an angiogram or

to observe for change needlessly prolongs the ischemic time. Fasciotomy

may be required but should be done in conjunction with and after reestablishment

of arterial flow. Local wound exploration is not recommended

because brisk hemorrhage may be encountered without the securing of

prior vascular control.

138-139. The answers are 138-c, 139-a. (Sabiston, 15/e, p 308.) Tension

pneumothorax is a life-threatening problem requiring immediate

treatment. A lung wound that behaves as a ball or flap valve allows escaped

air to build up pressure in the intrapleural space. This causes collapse of

the ipsilateral lung and shifting of the mediastinum and trachea to the contralateral

side, in addition to compression of the vena cava and contralateral

lung. Sudden death may ensue because of a decrease in cardiac output;

hypoxemia; and ventricular arrhythmias. To accomplish rapid decompression

of the pleural space, a large-gauge needle should be passed into the

intrapleural cavity through the second intercostal space at the midclavicular

line. This may be attached temporarily to an underwater seal with subsequent

insertion of a chest tube after the life-threatening urgency has been

relieved.

100 Surgery

Tension pneumothorax produces characteristic x-ray findings of ipsilateral

lung collapse, mediastinal and tracheal shift, and compression of the

contralateral lung. Occasionally, adhesions prevent complete lung collapse,

but the tension pneumothorax is evident because of the mediastinal displacement.

A pleural effusion would not be expected acutely in the absence

of associated intrapleural blood.

140. The answer is a. (Schwartz, 7/e, pp 103-105.) Though the immediate

release of catecholamines causes a transient drop in the insulin levels,

shortly thereafter there is a significant rise in plasma insulin levels in

injured humans. Since injured patients are highly hypermetabolic, it might

be expected that the activity of the thyroid hormones would be increased

following injury. This is not the case, however, and increased levels of the

thyroid hormones are not seen. Vasopressin (ADH) is regulated by the

serum osmolality. In the postinjury period many factors are at play that

provoke the excretion of vasopressin. Glucagon secretion is normal or

increased after injury; not only are aldosterone levels elevated, but the

diurnal fluctuations ordinarily seen are lost.

141. The answer is d. (Schwartz, 7/e, pp 192-193.) Traumatic injury to

the common bile duct must be considered in two separate categories. Complete

transection of the common bile duct can be handled in many ways. If

the patient is unstable and time is limited, simply placing a T tube in either

end of the open common bile duct and staging the repair is the treatment

of choice. In a stable patient a biliary enteric bypass is preferred. This can

be accomplished by Roux-en-Y choledochojejunostomy or cholecystojejunostomy.

The jejunum is favored over the duodenum because if the anastomosis

leaks, a lateral duodenal fistula is avoided. For similar reasons the

defunctionalizing of the jejunal limb is also preferable. This can be accomplished

by creating a Roux-en-Y limb of jejunum. Primary end-to-end

repair of a completely transected common bile duct is not recommended

because of the high incidence of stricture and need for reoperation and creation

of a biliary enteric bypass. However, primary repair is the procedure

of choice if the common bile duct is lacerated or only partially transected.

142. The answer is d. (Schwartz, 7/e, pp 163-166.) Reports of a more

than 50% incidence of negative explorations of the neck, iatrogenic complications,

and serious injuries overlooked at operation have caused a

Trauma and Shock Answers 101

reassessment of the dictum that all penetrating neck wounds that violate

the platysma must be explored. Stable patients with zone III (between the

angle of the mandible and the skull) or zone I (inferior to the cricoid cartilage)

injuries, or multiple neck wounds, should undergo initial angiography

irrespective of the ultimate treatment plan. Algorithms exist for

nonoperative management of asymptomatic patients that employ observation

alone or combinations of vascular and aerodigestive contrast studies

and endoscopy. Nevertheless, recognition of acute signs of airway distress

(stridor, hoarseness, dysphonia), visceral injury (subcutaneous air, hemoptysis,

dysphagia), hemorrhage (expanding hematoma, unchecked external

bleeding), or neurologic symptoms referable to carotid injury (stroke or

altered mental status) or lower cranial nerve or brachial plexus injury

requires formal neck exploration. Pneumothorax would mandate a chest

tube; the necessity for exploration would depend on clinical judgment and

institutional policy.

143. The answer is b. (Schwartz, 7/e, pp 194-195.) Duodenal

hematomas result from blunt abdominal trauma. They present as a high

bowel obstruction with abdominal pain and occasionally a palpable right

upper quadrant mass. An upper gastrointestinal series is almost always

diagnostic with the classic coiled spring appearance of the second and third

portions of the duodenum secondary to the crowding of the valvulae conniventes

(circular folds) by the hematoma. Nonsurgical management is the

mainstay of therapy because the vast majority of duodenal hematomas

resolve spontaneously. Simple evacuation of the hematoma is the operative

procedure of choice. However, bypass procedures and duodenal resection

have been performed for this problem. In patients with duodenal obstruction

from the superior mesenteric artery syndrome, the obstruction is usually

the result of a marked weight loss and, in conjunction with this, loss of

the retroperitoneal fat pad that elevates the superior mesenteric artery from

the third and fourth portions of the duodenum. Nutritional repletion and

replenishment of this fat pad will elevate the artery off the duodenum and

relieve the obstruction.

144. The answer is b. (Schwartz, 7/e, pp 1884-1885.) Transection of a

peripheral nerve results in hemorrhage and in retraction of the severed

nerve ends. Almost immediately, degeneration of the axon distal to the

injury begins. Degeneration also occurs in the proximal fragment back to

102 Surgery

the fist node of Ranvier. Phagocytosis of the degenerated axonal fragments

leaves a neurilemmal sheath with empty cylindrical spaces where the axons

were. Several days following the injury, axons from the proximal fragment

begin to regrow. If they make contact with the distal neurilemmal sheath,

regrowth occurs at about the rate of 1 mm per day. However, if associated

trauma, fracture, infection, or separation of neurilemmal sheath ends precludes

contact between axons, growth is haphazard and a traumatic neuroma

is formed. When neural transection is associated with widespread

soft tissue damage and hemorrhage (with increased probability of infection),

many surgeons choose to delay reapproximation of the severed nerve

end for 3-4 wk.

145-147. The answers are 145-a, 146-e, 147-b. (Schwartz, 7/e, pp

179-180.) Closed head injuries may result in cerebral concussion from

depression of the reticular formation of the brainstem. This type of injury

is usually reversible.

Local bleeding and swelling (intracranial or extracranial) produce an

increase in the intracranial pressure. A characteristic symptom pattern

occurs initiated by progressive depression of mental status. Increasing

intracranial pressure tends to displace brain tissue away from the source of

the pressure; if the pressure is sufficient, herniation of the uncal process

through the tentorium cerebri occurs.

Pupillary dilation is caused by compression of the ipsilateral oculomotor

nerve and its parasympathetic fibers. If the pressure is not relieved, the

contralateral oculomotor nerve will become involved and, ultimately, the

brainstem will herniate through the foramen magnum and cause death.

Hypertension and bradycardia are preterminal events.

Emergency measures to reduce intracranial pressure while preparing

for localization of the clot or for a craniotomy or both include hyperventilation,

dexamethasone (Decadron), and mannitol infusion. Of these,

hyperventilation produces the most rapid decrease in brain swelling.

148. The answer is a. (Schwartz, 7/e, pp 688-689.) Flail chest is diagnosed

in the presence of paradoxical respiratory movement in a portion of

the chest wall. At least two fractures in each of three adjacent rib or costal

cartilages are required to produce this condition. Complications of flail

chest include segmental pulmonary hypoventilation with subsequent

infection and ultimately respiratory failure. Management of flail chest

Trauma and Shock Answers 103

should be individualized. If adequate pain control and pulmonary toilet

can be provided, patients may be managed without stabilization of the flail.

Often, intercostal nerve blocks and tracheostomy aid in this form of management.

If stabilization is required, external methods such as sandbags or

towel clips are no longer used. Surgical stabilization with wires is used if

thoracotomy is to be performed for another indication. If this is not the

case, "internal" stabilization is performed by placing the patient on

mechanical ventilation with positive end-expiratory pressure. Tracheostomy

is recommended because these patients usually require 10-14 days

to stabilize their flail segment and postventilation pulmonary toilet is simplified

by tracheostomy. Indications for mechanical ventilation include significant

impedance to ventilation by the flail segment, large pulmonary

contusion, an uncooperative patient (e.g., owing to head injury), general

anesthesia for another indication, more than five ribs fractured, and the

development of respiratory failure.

149. The answer is c. (Schwartz, 7/e, pp 2048-2050.) The motor components

of the median nerve maintain the muscular function of most of the

long flexors of the hand as well as the pronators of the forearm and the

thenar muscles. The median nerve is also an extremely important sensory

innervator of the hand and is commonly described as the "eye of the hand"

because the palm, the thumb, and the index and middle fingers all receive

their sensation via the median nerve.

150. The answer is d. (Schwartz, 7/e, pp 238-239.) Carbon monoxide

(CO) is the leading cause of toxin-related death in the United States. It is

produced by the incomplete combustion of fossil fuels and is emitted by

virtually all gas-powered engines and appliances that burn fossil fuel, e.g.,

home furnaces, water heaters, stoves, pool heaters, kerosene heaters, and

charcoal fires. Tobacco smoke-particularly smoke released from the tip of

the cigarette, which has 2.5 times more CO than inhaled smoke-produces

a significant amount of the gas; nonsmokers working in closed quarters

with smokers may have carboxyhemoglobin (COHb) levels as high as 15%,

easily enough to cause headache and some impairment of judgment. Fire

fighters are at particularly high risk for CO intoxication. The pathophysiology

of CO poisoning is unclear. It is known to cause an adverse shift in the

oxygen-hemoglobin dissociation curve, to cause direct cardiovascular

depression, and to inhibit cytochrome A3. Tissue hypoxia is the result.

104 Surgery

Treatment is directed toward increasing the partial pressures of O2 to which

the transalveolar hemoglobin is exposed. In most cases, administering

100% oxygen through a tightly fitted face mask will result in a serum elimination

half-life of COHb of 80 min (compared with 520 min when one

breathes room air). In severe cases, where coma, seizures, or respiratory

failure are present, the partial pressure of O2 is increased by administering

it in a hyperbaric chamber with an atmospheric pressure of 2.8. In this situation

the serum elimination half-life is reduced to 23 min. In any case, the

oxygen therapy should continue until the COHb levels reach 10%.

151. The answer is d. (Schwartz, 7/e, pp 169, 204.) Most pelvic fractures

are the result of automobile-pedestrian accidents and these fractures are a

frequent cause of death. The pelvis is extremely vascular with a diffuse

blood supply that makes hemorrhage common and surgical control of

bleeding difficult. This patient has a type II fracture (single break in pelvic

ring) through a non-weight-bearing portion of the pelvis. These fractures

are best treated by bed rest until hemodynamic stability is assured and

thereafter by gentle ambulation as pain permits. The clinician must watch

carefully for associated injuries to bladder, urethra, and colon and be alert

to the many other possible concurrent injuries to an elderly patient who

has suffered a collision, even a low-velocity attack from a pizza man.

152. The answer is d. (Schwartz, 7/e, pp 250-252.) The treatment of

electrical injury should be modified from that of thermal burns because tissue

damage is much deeper than is apparent at first inspection. The heat

generated is proportional to the resistance to the flow of current. Bone, fat,

and tendons offer the greatest resistance. Therefore, the tissue deep within

the center of an extremity may be injured while more superficial tissues are

spared. For this reason, the quantification of fluid requirements cannot be

based on the percentage of body surface area involved, as in the Parkland,

Brooke, or Baxter formulas, which are used to calculate fluid replacement

after thermal burns. Massive fluid replacement is usually essential. A brisk

urine output is desirable because of the likelihood of myonecrosis with

consequent myoglobinuria and renal damage. As with deep thermal burns,

debridement, skin grafting, and amputation of extremities may be required

following electrical injury. However, fasciotomy is more frequently

required than escharotomy with electrical injury because deep myonecrosis

results in increased intracompartmental pressures and compromised

Trauma and Shock Answers 105

limb perfusion. In addition, distant fractures may result owing to vigorous

muscle contraction during the accident or if subsequent falls occur. Cardiac

or respiratory arrest may occur if the pathway of the current includes

the heart or brain. An electrical current can also damage the pulmonary

alveoli and capillaries and lead to respiratory infections, a major cause of

death in these victims. Owing to the deep myonecrosis that often accompanies

high-voltage injury, prophylaxis for clostridia with high-dose penicillin

may be considered. Mafenide acetate is preferred over other topical

antimicrobials because of its deeper penetration of eschar.

153. The answer is a. (Bunt, Am J Surg 160:226-228, 1990.) In a 4-year

retrospective study of 569 at-risk parajoint fractures or dislocations resulting

from blunt trauma, there was only a 1.5% incidence of associated vascular

injury. Angiograms and vascular surgical consultations were obtained

when vascular compromise was suspected owing to clinical examination or

Doppler confirmation of flow abnormalities. While vascular injuries due to

fractures on either side of a joint (e.g., supracondylar femur fracture or tibial

plateau fracture) were uncommon, major joint dislocations were more

commonly associated with vascular injury. An exception to this rule is the

type III supracondylar humerus fracture, where displacement of bone may

injure or entrap the tethered brachial artery. Clavicular fractures are rarely

associated with significant vascular injury. The highest rate of vascular

injury occurs with knee dislocations because of the extreme force required

to dislocate the joint. In open elbow dislocations, the brachial artery is

often disrupted by forcible hyperextension of the joint; closed elbow dislocations

are rarely associated with vascular injury unless the dislocation is

anterior.

154. The answer is d. (Greenfield, 2/e, pp 317-331.) Gunshot wounds to

the lower chest are often associated with intraabdominal injuries. The

diaphragm can rise to the level of T4 during maximal expiration. Therefore,

any patient with a gunshot wound below the level of T4 should be

subjected to abdominal exploration. Exploratory thoracotomy is not indicated

because most parenchymal lung injuries will stop bleeding and heal

spontaneously with the use of tube thoracostomy alone. Indication for thoracic

exploration for bleeding is usually in the range of 100-150 mL/h over

several hours. Peritoneal lavage is not indicated even though the abdominal

examination is unremarkable. As many as 25% of patients with nega-

106 Surgery

tive physical findings and negative peritoneal lavage will have significant

intraabdominal injuries in this setting. These injuries include damage to

the colon, kidney, pancreas, aorta, and diaphragm. Local wound exploration

is not recommended because the determination of diaphragmatic

injury with this technique is unreliable.

155. The answer is e. (Sabiston, 15/e, pp 297-298.) Loss of consciousness

following head trauma should be assumed to be due to intracranial hemorrhage

until proved otherwise. However, a thorough evaluation of the

head-injured patient includes assessment for other potentially lifethreatening

injuries. Rarely, a patient may have sufficient hemorrhage from

a scalp laceration to cause hypotension. In the patient described, hypotension

and tachycardia should not be uncritically attributed to the head

injury, since these findings in the setting of blunt trauma are suggestive of

serious thoracic, abdominal, or pelvic hemorrhage. When cardiovascular

collapse occurs as a result of rising intracranial pressure, it is generally

accompanied by hypertension, bradycardia, and respiratory depression.

156. The answer is b. (Sabiston, 15/e, pp 324-325.) Because of the colon's

poor blood supply and its fecal content, colon injuries are more difficult to

manage than small-bowel injuries. Recently the necessity of mandatory

colostomy for civilian colon injuries has been questioned. About 85% of

civilian colon injuries are small wounds from low- or medium-velocity gunshots

or stab wounds, which are less likely to produce gross fecal spillage.

These injuries can be repaired primarily in the absence of gross contamination,

regardless of the right- or left-sided location of injury. Shock on admission

and multiple associated injuries are not universally viewed as absolute

contraindications to primary repair in such cases. Gross contamination or

large amounts of hard intraluminal feces remain generally accepted contraindications

to primary repair. Alternatives include end colostomy with

mucous fistula or Hartmann's pouch, exteriorization of a primary repair,

and protection of a primary repair in the distal colon by formation of a proximal

colostomy. In all cases in which traumatic colon injury is suspected, the

early administration of broad-spectrum intravenous antibiotics seems to

reduce the incidence of postoperative infectious complications.

157. The answer is d. (Sabiston, 15/e, pp 269-270.) Because they are so

often malnourished and at high risk for other conditions that alter their

Trauma and Shock Answers 107

immunocompetence, drug addicts have an extraordinary susceptibility to

infections of the type that can quickly progress to threaten life and limb.

Among the most virulent are those that give rise to anaerobic cellulitis.

Terms sometimes used for these infections are gas abscess, gangrenous cellulitis,

localized gas gangrene, and epifascial gangrene. Suppuration and extensive

gas formation are common and usually localized, unlike the infections

associated with myonecrosis. These lesions may be clostridial or nonclostridial.

Clostridium perfringens is the most common culprit, but anaerobic

cellulitis and gas formation have been associated with a variety of

obligate anaerobes including Bacteroides species, Peptostreptococcus, and

Peptococcus, and the gram-negative enteric bacilli (E. coli, Klebsiella),

staphylococci, and streptococci. Pseudomonas aeruginosa is not implicated

in these aggressive infections. Since the progressive injury results from liberation

of bacterial exotoxins, antitoxin administration at this stage is futile.

Treatment is determined by immediate inspection of a Gram stain of the

thin, dark, malodorous wound drainage or a needle aspirate of the crepitant

area: if large, "boxcar-shaped" gram-positive bacilli are present, it is a

clostridial infection and high doses of parenteral penicillin G (20 million

U/day) are indicated; if a polymicrobial Gram stain is seen, clindamycinaminoglycoside

should be added until specific sensitivities are known.

Aggressive debridement is always indicated.

158. The answer is c. (Dubrow, Surgery 106:267-273, 1989. Miller, Arch

Surg 124:805-807, 1989.) The spectrum of blunt cardiac injuries includes

myocardial contusion, rupture, and internal (chamber and septal) disruptions

such as traumatic septal defects, papillary muscle tears, and valvular

tears. Myocardial contusions are by far the most common of these injuries.

They usually occur in persons who sustain a direct blow to the sternum, as

seen in a driver whose sternum is forcibly compressed by the steering column

in a deceleration injury. Over 50% of patients with myocardial contusion

demonstrate external signs of thoracic trauma, including sternal

tenderness, abrasions, ecchymosis, palpable crepitus, rib fractures, or flail

segments. Overall, fewer than 10% of patients have conduction abnormalities,

dysrhythmias, or ischemic patterns on initial ECG. Elevated cardiac

isoenzyme levels are specific for myocardial injury, but they lack clinical

significance in patients without ECG abnormalities or hemodynamic instability.

First-pass radionuclide angiography (RNA) and echocardiography

provide sensitive assessment of ventricular wall motion and ejection frac-

108 Surgery

tion after blunt chest trauma and are currently viewed as the "gold standard"

for the diagnosis of myocardial contusion. But while RNA and

echocardiography sensitively detect small abnormalities in myocardial

function, they are poor predictors of the significant cardiac complications

of pump failure and arrhythmia. Traditionally, management of patients

with myocardial contusion has included continuous ECG monitoring in an

intensive care unit for 48-72 h, even in hemodynamically stable patients

without other injuries. Because of the large number of patients with blunt

chest trauma from automobile accidents, however, this policy has been

scrutinized. Virtually all patients who develop cardiac complications display

ECG abnormalities on arrival in the emergency room or within the

first 24 h. Since an abnormal ECG is a good predictor of subsequent complications,

stable patients with possible myocardial contusions but with a

normal ECG tracing may be placed on telemetry for 24 h, rather than monitored

in an ICU.

159. The answer is d. (Weissman, Anesthesiology 73:308-327, 1990.)

Injury and sepsis result in accelerated protein breakdown with increased

urinary nitrogen loss and increased peripheral release of amino acids. The

negative nitrogen balance represents the net result of breakdown and synthesis

(with breakdown increased and synthesis increased or diminished).

Amino acids such as alanine are released by muscle and transported to the

liver for incorporation into acute-phase proteins including fibrinogen,

complement, haptoglobin, and ferritin. The amino acids also undergo gluconeogenesis

to glucose, which is utilized primarily by the brain and other

glycolytic tissues such as peripheral nerves, erythrocytes, and bone marrow.

Other tissues receive energy from fat in the form of fatty acids or

ketone bodies during starvation following major trauma; this helps to conserve

body protein. Glutamine is the most abundant amino acid in the

blood, and its levels in muscle and blood decrease following injury and

sepsis as it is consumed rapidly by replicating fibroblasts, lymphocytes,

and intestinal endothelial cells. The use of glutamine may decrease protein

catabolism in the intestine and may help prevent atrophy of the gastrointestinal

tract in starved and parenterally nourished patients. Along with the

counterregulatory hormones (glucagon, epinephrine, cortisol), interleukin

1 appears to mediate muscle breakdown. Recent studies have indicated

that TNF (also called cachectin because of the role it plays in muscle wasting

in septic or oncologic patients) also may be a principal catabolic

Trauma and Shock Answers 109

cytokine in the traumatized patient. This protein is secreted by

macrophages and further affects metabolism by inducing secretion of interleukin

1 and inhibiting synthesis and activity of lipogenic enzymes.

160. The answer is e. (Sabiston, 15/e, pp 324-325. Schwartz, 7/e, pp

199-200.) Penetrating injury to the intraperitoneal or extraperitoneal rectum

should be diagnosed by immediate sigmoidoscopy. Contrast studies of

the rectum, when sigmoidoscopy is inconclusive, should use a watersoluble

radiopaque medium such as Gastrografin. The use of barium is

contraindicated because its spillage in the peritoneal cavity mixed with

feces would increase the likelihood of subsequent intraabdominal

abscesses. Instrumentation of the bullet track is also contraindicated

because of the risk of injury to adjacent structures (e.g., bladder, ureters,

iliac vessels). Angiography is not a sensitive method for demonstrating

injury of the intestinal wall.

161. The answer is d. (Schwartz, 7/e, pp 188-192.) The overwhelming

majority of patients explored for blunt trauma to the liver sustain their

injuries in motor vehicle accidents. In a large consecutive series of 323

patients with blunt hepatic trauma who were explored for the finding of

hemoperitoneum on peritoneal lavage, the mortality was 31%. Forty-two

percent of the deaths, due primarily to liver injury, occurred intraoperatively

during the initial operation following admission. All operations were

performed at a regional trauma center by staff trauma surgeons. Their findings

included the following observations: (1) intraoperative deaths were

due to uncontrolled hemorrhage; (2) patients with major hepatic injuries

who survived operation but nevertheless died appeared to succumb either

to sepsis or to associated injuries, usually involving the head or chest; (3)

hepatic artery ligation for control of bleeding yielded dismal results-of the

3 surviving patients who underwent hepatic artery ligation (an additional

11 died), 2 required reoperation for continued bleeding; (4) the use of

drains (passive and active) was associated with a significantly greater incidence

of intraabdominal infectious complications; (5) intracaval shunting

was used in 7 severely injured patients without a survivor; (6) while minor

hepatic injuries required little or no treatment, major lacerations could

usually be controlled with simple absorbable sutures placed 2-3 cm from

the fracture edge, without occurrence of subsequent intrahepatic

hematoma, hemobilia, or bile fistulae; (7) hepatic fragmentation may be

110 Surgery

treated by nonanatomic debridement, with suture ligation of individual

bleeding points-of nine attempts at formal anatomic resection in stable

patients, all ended in uncontrollable hemorrhage and death.

162. The answer is a. (Schwartz, 7/e, pp 172-175, 204-206.) The presence

of ischemic changes following vascular trauma is an indication for

emergency exploration and repair. Nonsurgical management of arterial

trauma when distal pulses are palpable may lead to delayed sequelae of

embolization, occlusion, secondary hemorrhage, false aneurysm, and traumatic

arteriovenous fistula. The presence of palpable pulses does not reliably

exclude significant arterial injury. Injuries that may be missed if

exploration is not performed include lacerations and partial transections

containing hematomas, intramural or intraluminal thromboses, and intimal

disruptions or tears. Injury to motor nerves would be apparent on neurologic

examination. Injury to bone would be diagnosed by x-ray. Adjacent

venous injury, in the absence of an expanding hematoma, would not by

itself mandate exploration because there are numerous collateral venous

channels in the extremities. Prophylactic fasciotomy is not routinely performed

for all arterial injuries but is indicated in the presence of an

ischemic period exceeding 4-6 h, combined arterial and major venous

injury, prolonged periods of hypotension, massive associated soft tissue

trauma, and massive edema.

163. The answer is d. (Schwartz, 7/e, pp 102-105.) The biochemical

changes associated with shock result from tissue hypoperfusion, endocrine

response to stress, and specific organ system failure. During shock, the

sympathetic nervous system and adrenal medulla are stimulated to release

catecholamines. Renin, angiotensin, antidiuretic hormone, adrenocorticotropin,

and cortisol levels increase. Resultant changes include sodium

and water retention and an increase in potassium excretion, protein catabolism,

and gluconeogenesis. Potassium levels rise as a result of increased

tissue release, anaerobic metabolism, and decreased renal perfusion. If

renal function is maintained, potassium excretion is high and normal

plasma potassium levels are restored.

164. The answer is d. (Sabiston, 15/e, pp 1277-1278.) A subperichondrial

hematoma in the pinna of the ear may lead to avascular necrosis of the

cartilage with shriveling of the pinna and fibrosis and calcification of the

Trauma and Shock Answers 111

hematoma. The result is the deformity known as "cauliflower ear." Appropriate

treatment consists of evacuation of the hematoma by incision and

tight packing of the skin and perichondrium onto the cartilage with a pressure

dressing. Needle aspiration does not effect adequate drainage. Ice

packs may be helpful early, but are not sufficient to prevent the deformity;

antibiotics are not indicated for this lesion. Since the hematoma is subperichondrial,

excision of the hematoma would remove the perichondrium

and lead to cartilage deformities.

165. The answer is c. (Sabiston, 15/e, pp 83-84, 123.) Infusion of lactated

Ringer's solution is an effective immediate step, both clinically and experimentally,

in managing hypovolemic shock. Use of this balanced salt solution

helps correct the fluid deficit (in the extracellular, extravascular

compartment) resulting from hypovolemic shock. This procedure may

decrease requirements for whole blood in patients with hemorrhagic

shock. If blood loss has been minimal and is controlled, whole blood transfusion

may be avoided entirely. The theoretical objection to infusion of lactated

Ringer's solution is that it will increase lactate levels and compound

the problem of lactic acidosis. This has not been borne out in animal or

clinical studies. Along with the hemodynamic improvement that follows

volume restitution, liver function improves, lactate metabolism is

improved, excess lactate levels drop, and metabolic acidosis improves.

166-167. The answers are 166-e, 167-d. (Cass, Urol Clin North Am

16:213-220, 1989.) In stable patients with suspected genitourinary tract

injury, the first urologic study other than urinalysis should be the intravenous

urogram. The technique of high-dose drip infusion is desirable

because the high concentration of contrast achieved greatly facilitates interpretation

in an unprepared patient. Intravenous pyelography should be

performed before retrograde cystography to avoid obscuring visualization

of the lower ureteral tract. The study also may preclude the need for retrograde

urethrography in cases where, unlike the case presented, there is a

suspicion of urethral injury. Renal arteriography is not indicated routinely

but should be performed to rule out renal pedicle injury when no kidney

function is demonstrated by drip infusion urography. Peritoneal lavage is

not useful in the diagnosis of genitourinary injuries because the structures

are retroperitoneal. Seventy to eighty percent of patients with blunt renal

trauma are successfully treated nonsurgically. Bed rest may reduce the like-

112 Surgery

lihood of secondary hemorrhage; antibiotics may reduce the chance of

infection's developing in a perirenal hematoma. Failure of conservative

treatment is indicated by rising fever, increasing leukocytosis, evidence of

secondary hemorrhage, and persistent or increasing pain and tenderness in

the region of the kidney.

168. The answer is e. (Sabiston, 15/e, pp 315-317.) The majority of penetrating

pancreatic injuries can be managed with simple drainage. Injury to

the major pancreatic duct to the left of the mesenteric vessels is effectively

treated with a distal pancreatectomy. The high morbidity and mortality of

a pancreaticoduodenectomy for trauma limit its use to extensive blunt

injuries to both pancreatic head and duodenum. For ductal injury in the

region of the head of the pancreas, a Roux-en-Y limb of jejunum should be

brought up and used to drain the transected duct. The proximity of the

pancreas to many other major structures makes combined injuries frequent

(90%). Complications of pancreatic injury include fistula, pseudocyst, and

abscess, but the cause of death in patients with pancreatic injury is most

frequently exsanguination from associated injury to major vascular structures

such as the splenic vessels, mesenteric vessels, aorta, or inferior vena

cava. Finally, however small, all peripancreatic hematomas should be

explored to search for pancreatic injury. Simple drainage is usually adequate

treatment in such cases, but failure to recognize a pancreatic injury

can have catastrophic sequelae.

169. The answer is d. (Dutky, J Trauma 29:856-860, 1989.) Rapid fluid

administration is often the key to successful trauma resuscitation. Some of

the important factors affecting the rate of fluid resuscitation include the

diameter of the intravenous tubing, the size and length of the venous cannulae,

the fluid viscosity, and the site of administration. According to

Poiseuille's law, flow is proportional to the fourth power of the radius of a

catheter and inversely proportional to its length. Therefore, the shorter a

catheter and the larger its diameter, the faster one can infuse a solution

through it. Central venous placement alone does not assure rapid flow.

Importantly, the diameter of the intravenous tubing employed may be the

rate-determining factor in fluid delivery: blood-infusion tubing allows

twice the flow of standard intravenous tubing and should be used when

rapid fluid resuscitation is needed. Any patient who is suspected of having

a major abdominal injury should immediately have at least two short,

Trauma and Shock Answers 113

large-bore (16-gauge or larger) intravenous cannulae placed in peripheral

veins. Longer, smaller catheters, such as standard 18-gauge central venous

catheters, may take more time to place and will have lower flow rates. Once

fluid resuscitation is under way, one may elect to place an 8- or 9-French

pulmonary artery catheter-introducer via a central venous approach for

further volume administration, as well as for measurement of central

venous pressure or for Swan-Ganz catheter insertion. Lower-extremity

venous cannulae, placed by saphenous vein cutdown or percutaneously

into the femoral veins, are no longer advised as primary access for patients

with abdominal trauma, since possible disruption of iliac veins or the inferior

vena cava will render volume infusion ineffective. Studies have demonstrated

that the flow rate of cold whole blood is roughly two-thirds that of

whole blood at room temperature. Diluting and warming the blood by

"piggybacking" it into infusion lines that are delivering crystalloid will

decrease the blood's viscosity, enhance flow, and minimize hypothermia.

170. The answer is c. (Flint, Ann Surg 211:703-707, 1990. Trunkey, Can J

Surg 27:479-486, 1984.) The pneumatic antishock garment (PASG) is composed

of inflatable overalls with three compartments, two for the legs and

one for the abdomen. It has now been convincingly demonstrated that the

PASG elevates blood pressure by increasing peripheral vascular resistance

rather than by an "autotransfusion" effect on venous return and increased

cardiac output. The PASG is beneficial for controlling bleeding from pelvic

fractures by reduction of pelvic volume and immobilization to restrict fracture

movement. The suit pressure must be released very slowly because

rapid deflation can lead to sudden, irreversible hypotension. This is probably

due to a sudden decrease in peripheral vascular resistance and to the

effects of vasodilation and wash-out of accumulated metabolites of capillary

beds under the suit. Upon reperfusion of the lower body, a systemic

metabolic acidemia with hyperkalemia may result and must be closely

monitored. For these reasons satisfactory intravenous volume must be

attained prior to decompression of the PASG, a delay that may prevent adequate

early evaluation of concealed injuries to the lower body.

171. The answer is c. (Schwartz, 6/e, p 675.) Although indications for

thoracotomy in the emergency room are controversial, the procedure

appears to be most beneficial when it is employed to (1) release cardiac

tamponade in patients with penetrating thoracic trauma who are deterio-

114 Surgery

rating too rapidly for a subxiphoid pericardial window to be created; (2)

allow cross-clamping of the descending aorta in patients with intraabdominal

bleeding for whom other measures are not effective in maintaining

blood pressure; and (3) allow effective internal cardiac massage in patients

who arrive in the emergency room with faint or absent pulses and distant

heart sounds, and for whom other resuscitative efforts are unsuccessful. By

contrast, existing evidence suggests that patients who are unsalvageable

and do not benefit from emergency room thoracotomy include (1) those

with no vital signs (pulse, pupillary reaction, spontaneous respiration) in

the field and (2) those with blunt trauma to multiple organ systems and

absent vital signs upon arrival in the emergency room.

172. The answer is c. (Schwartz, 6/e, pp 1181-1182.) Most enterocutaneous

fistulas result from trauma sustained during surgical procedures.

Irradiated, obstructed, and inflamed intestine is prone to fistulization.

Complications of fistulas include fluid and electrolyte depletion, skin

necrosis, and malnutrition. Fistulas are classified according to their location

and the volume of output, because these factors influence prognosis

and treatment. When the patient is stable, a barium swallow is obtained to

determine (1) the location of the fistula, (2) the relation of the fistula to

other hollow intraabdominal organs, and (3) whether there is distal

obstruction. Proximal small-bowel fistulas tend to produce a high output

of intestinal fluid and are less likely to close with conservative management

than are distal, low-output fistulas. Small-bowel fistulas that communicate

with other organs, particularly the ureter and bladder, may need aggressive

surgical repair because of the risk of associated infections. The presence of

obstruction distal to the fistula (e.g., an anastomotic stricture) can be diagnosed

by barium contrast study and mandates correction of the obstruction.

When these poor prognostic factors for stabilization and spontaneous

closure are observed, early surgical intervention must be undertaken. The

patient in the question, however, appears to have a low-output, distal enterocutaneous

fistula. Control of the fistulous drainage should be provided by

percutaneous intubation of the tract with a soft catheter. This is usually

accomplished under fluoroscopic guidance. Antispasmodic drugs have not

been proved effective; somatostatin has been used with mixed success in

the setting of high-output (greater than 500 mL/day) fistulas. There is no

indication for antibiotics in the absence of sepsis. Total parenteral nutrition

(TPN) is given to maintain or restore the patient's nutritional balance while

Trauma and Shock Answers 115

minimizing the quantity of dietary fluids and endogenous secretions in the

gastrointestinal tract. A period of 4-6 wk of TPN therapy is warranted to

allow for spontaneous closure of a low-output, distal fistula. Should conservative

management fail, surgical closure of the fistula is performed.

173. The answer is d. (Schwartz, 6/e, pp 981-982.) Traumatic arterial

injuries can be handled with several techniques. The basic principles of

debridement of injured tissue and reestablishment of flow should be

observed. Primary end-to-end anastomosis is preferable if this can be

accomplished without tension. When 5 cm of artery has been destroyed, it

is impossible to perform a tension-free primary anastomosis, and a

reversed saphenous vein graft is the repair of choice. Ligation of the artery

is to be avoided in order to prevent gangrene and limb loss. The use of

prosthetic material (Gore-Tex) in a potentially infected field is also to be

avoided as infection at the suture line often leads to delayed hemorrhage.

Harvesting an arterial graft of similar diameter from elsewhere in the body

is hazardous and unnecessary when vein is available.

174. The answer is c. (Cameron, 4/e, pp 820-824.) Traumatic injuries to

the diaphragm are associated with both blunt and penetrating trauma. The

spleen, kidneys, intestines, and liver are the most frequently injured

abdominal organs in blunt trauma; the diaphragm is the least. Missed

injuries lead to problems with herniation and bowel strangulation with sufficient

frequency that repair should not be delayed. All such injuries

require repair once the diagnosis is made and the patient has been stabilized.

Most acute defects in the diaphragm can be repaired via an abdominal

approach, which allows exploration for coexisting injuries.

175-177. The answers are 175-a, d; 176-a, b, e; 177-c. (Davis, pp

2789-2790. Walters, Surg Gynecol Obstet 165:496-502, 1988.) Peritoneal

lavage is a diagnostic technique used to identify occult intraperitoneal injury

in patients with abdominal trauma. An abnormal lavage is obtained when the

lavage effluent exceeds allowable levels of blood, bile, or amylase; the presence

of vegetable matter also constitutes an abnormal result. Lavage has been

used most widely in the triage of hemodynamically stable victims of abdominal

trauma who are suspected of having significant injuries but who manifest

equivocal physical findings. Further indications for lavage are the

suspicion of abdominal injury in patients with altered sensoria, patients with

116 Surgery

unexplained blood loss, and patients who require general anesthesia to treat

other injuries. The technique is exquisitely sensitive to intraabdominal bleeding

and will detect as little as 20 mL of free blood in the peritoneal cavity.

Because stable retroperitoneal hematomas and minor lacerations of the liver

and spleen often shed sufficient blood to produce a positive lavage, some

authors have advocated abdominal CT as the preferred method of identifying

occult operable injuries of the abdomen. Also, CT with oral and intravenous

contrast can provide accurate images of the injured retroperitoneum and the

solid intraabdominal viscera (as lavage cannot). Neither CT nor lavage has

been a reliable indicator of small intestinal and diaphragmatic injuries, and

neither has been useful in obtaining hemostasis nonoperatively. Angiography,

however, may be employed to demonstrate visceral or pelvic arterial extravasation

and to control hemorrhage by selective embolization.

178-180. The answers are 178-d, e, f; 179-d, e, j; 180-b, c, f, h.

(Schwartz, 6/e, pp 193-219.) Deceleration injuries commonly result from

high-speed motor vehicle accidents and falls from considerable heights.

The mechanism of injury is the shearing of pedicled organs from their

points of attachment to the retroperitoneum. Because these pedicles are

usually vascular, the injury results in bleeding and ischemia of the affected

organ. Pedicled organs in the abdomen include the intestines (small and

large) and the kidneys. Deceleration injuries to the aorta occur in the mediastinum

and are usually fatal.

The small intestine and its mesentery is by far the most commonly

injured abdominal organ in penetrating trauma because of its sheer mass

and central location. A midline bullet at the level of the umbilicus is most

likely to strike small intestine, the transverse colon, and perhaps the aorta

or vena cava. The great vessels bifurcate just at the level of the umbilicus.

The diaphragm, stomach, and pancreas would be superior to this injury;

the bladder below; and the liver, spleen, and kidneys lateral.

The relative incidence of organ injury in blunt trauma is highest for

solid organs (spleen, liver, and kidneys). Although hollow viscera are less

likely to be injured by blunt trauma, this rule does not apply when the hollow

viscus is full; for example, rupture of a full urinary bladder is frequently

described when blunt force is applied to the lower abdomen. In

addition to the spleen, liver, and kidneys, extreme blunt force to the upper

abdomen may fracture the pancreas, which is susceptible to injury because

of its position overlying the rigid spinal column.

Trauma and Shock Answers 117

181-185. The answers are 181-b, 182-e, 183-a, 184-d, 185-c.

(Schwartz, 6/e, pp 672-684.) Flail chest describes the paradoxical motion of

the chest wall that occurs when consecutive ribs are broken in more than

one place, usually following blunt trauma to the thorax. Respiratory distress

may ensue when the noncompliant flail segment interferes with generation

of adequate positive and negative intrathoracic pressure needed to

move air through the trachea. In addition, a blow sufficiently violent to

cause a flail chest may also contuse the underlying pulmonary

parenchyma, which compounds the respiratory distress. Treatment consists

of stabilizing the chest wall. Although some temporary benefit may be

gained by external buttressing of the chest (e.g., with sandbags, or by turning

the patient onto the affected side), endotracheal intubation provides

rapid and safe control of the airway, as well as stabilization of the chest

internally by positive pressure ventilation.

Airway obstruction denotes partial or complete occlusion of the tracheobronchial

tree by foreign bodies, secretions, or crush injuries of the

upper respiratory tract. Patients may present with symptoms ranging from

cough and mild dyspnea to stridor and hypoxic cardiac arrest. An initial

effort should be made to digitally clear the airway and to suction visible

secretions; in selected, stable patients, fiberoptic endoscopy may be

employed to determine the cause of obstruction and to retrieve foreign

objects. Unstable patients whose airways cannot be quickly reestablished

by clearing the oropharynx must be intubated. An endotracheal intubation

may be attempted, but cricothyroidotomy is indicated in the presence of

proximal obstruction or severe maxillofacial trauma.

Blunt or penetrating trauma to the pericardium and heart will result in

pericardial tamponade when fluid pressure in the pericardial space exceeds

central venous pressure and thus prevents venous return to the heart. The

result is shock, despite adequate volume and myocardial function. The treatment

is pericardial decompression. A subxiphoid, supradiaphragmatic incision

and creation of a pericardial "window," ideally performed in the

operating room, provides a rapid, safe means of confirming the diagnosis of

tamponade and of relieving venous obstruction. If heavy bleeding is encountered

on opening the pericardial window, a sternotomy may be performed.

Tension pneumothorax occurs when a laceration of the visceral pulmonary

pleura acts as a one-way valve that allows air to enter the pleural

space from an underlying parenchymal injury but not to escape. Increasing

intrapleural pressure causes collapse of the ipsilateral lung, compression of

118 Surgery

the contralateral lung due to mediastinal shift toward the opposite

hemithorax, and diminished venous return. Treatment consists of relieving

the pneumothorax. This is best accomplished by tube thoracostomy.

Open pneumothorax occurs when a traumatic defect in the chest wall

permits free communication of the pleural space with atmospheric pressure.

If the defect is larger than two-thirds of the tracheal diameter, respiratory

efforts will move air in and out through the defect in the chest wall

rather than through the trachea. The immediate treatment is placement of

an occlusive dressing over the defect; subsequent interventions include

placement of a thoracostomy tube (preferably through a separate incision),

formal closure of the chest wall, and ventilatory assistance if needed.

Trauma and Shock Answers 119

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TRANSPLANTS,

IMMUNOLOGY,AND

ONCOLOGY

Questions

DIRECTIONS: Each item below contains a question or incomplete

statement followed by suggested responses. Select the one best response to

each question.

121

186. Tissue injury or infection

results in the release of tumor

necrosis factor (TNF) by which of

the following cells?

a. Fibroblasts

b. Damaged vascular endothelial cells

c. Monocytes/macrophages

d. Activated T lymphocytes

e. Activated killer lymphocytes

187. A cross-match is performed

by incubating

a. Donor serum with recipient lymphocytes

and complement

b. Donor lymphocytes with recipient

serum and complement

c. Donor lymphocytes with recipient

lymphocytes

d. Recipient serum with a known

panel of multiple donor lymphocytes

e. Recipient serum with donor red

blood cells and complement

188. In order to activate

helper/inducer T (CD41) lymphocytes,

macrophages release

a. Interleukin 1

b. Interleukin 2

c. Interleukin 3

d. Interleukin 4

e. Interferon

189. Which of the following cells

cause immunologically restricted

tumor cell lysis?

a. Macrophages

b. Cytotoxic T lymphocytes

c. Natural killer cells

d. Polymorphonuclear leukocytes

e. Helper T lymphocytes

Terms of Use

190. The primary mechanism of

action of cyclosporine A is inhibition

of

a. Macrophage function

b. Antibody production

c. Interleukin 1 production

d. Interleukin 2 production

e. Cytotoxic T-cell effectiveness

Items 191-192

A 24-year-old woman presents

with lethargy, anorexia, tachypnea,

and weakness. Laboratory studies

reveal a BUN of 150 mg/dL, serum

creatinine of 16 mg/dL, and potassium

of 6.2 meq/L. Chest x-ray

shows increased pulmonary vascularity

and a dilated heart.

191. Management of this patient

would include

a. Emergency kidney transplantation

b. Creation and immediate use of a

forearm arteriovenous fistula

c. Sodium polystyrene sulfonate

(Kayexalate) enemas

d. A 100-g protein diet

e. Cardiac biopsy via femoral vein

catheterization

192. In the course of 3 mo of treatment,

the patient's congestive heart

failure resolves, the lethargy and

weakness diminish markedly, and

she is able to return to work parttime.

Family immune profile studies

reveal that her mother and her

father both are haplotype identical

with regard to HLA antigens and

that her sister is a six-antigen

match. The patient at this time

should be urged to

a. Continue hemodialysis three times

a week

b. Undergo cadaveric renal transplantation

c. Accept a kidney transplant from

her sister

d. Accept a kidney transplant from

her father

e. Accept a kidney transplant from

her mother

193. After the first postoperative

year of cardiac transplantation, the

most common cause of death is

a. Infection

b. Arrhythmia

c. Accelerated graft arteriosclerosis

d. Acute rejection episode

e. Cancer

122 Surgery

194. Which of the following precludes cadaveric renal transplantation?

a. Positive cross-match

b. Donor blood type O

c. Two-antigen HLA match with donor

d. Blood pressure of 180/100 mm Hg

e. Hemoglobin level of 8.2 g/dL

195. Which of the following statements regarding hyperacute rejection of

a transplanted kidney is true?

Transplants,Immunology,and Oncology 123

a. It is mediated by preformed donor antibodies against recipient HLA antigens

b. It can be prevented by performing lymphocytotoxicity cross-match testing

c. It is manifest grossly by a swollen, pale kidney at the time of transplant surgery

d. This form of rejection is associated with disseminated intravascular coagulation

(DIC)

e. The rejection process can be treated with a steroid bolus and OKT3

196. Which of the following statements

regarding heart transplantation

is true?

a. Heart transplants are matched by

size and ABO blood type rather

than tissue typing

b. Cadaveric graft survival is significantly

lower with heart transplants

as compared with renal transplants

c. Cold ischemia time for donor hearts

should not be more than 48 h

d. The upper age limit for heart transplant

eligibility is 55 years

e. The leading cause of death after the

first year of cardiac transplantation

is chronic rejection

197. A 47-year-old man with

hypertensive nephropathy develops

fever, graft tenderness, and

oliguria 4 wk following cadaveric

renal transplantation. Serum creatinine

is 3.1 mg/dL. A renal ultrasound

reveals mild edema of the

renal papillae but normal flow in

both the renal artery and renal vein.

Nuclear scan demonstrates sluggish

uptake and excretion. The

next most appropriate step is

a. Performing an angiogram

b. Decreasing steroid and cyclosporine

dose

c. Beginning intravenous antibiotics

d. Performing renal biopsy, steroid

boost, and immunoglobulin therapy

e. Beginning FK 506

198. Posttransplant cytomegalovirus

infection may cause

a. Plyelonephritis

b. GI ulceration and hemorrhage

c. Cholecystitis

d. Intraabdominal abscess

e. Parotitis

199. In centers with experienced

personnel, 1-year liver transplant

survival is now approximately

a. 95%

b. 80%

c. 65%

d. 50%

e. 35%

200. Graft-versus-host disease has

occurred with the transplantation

of which of the following?

a. Kidney

b. Lung

c. Heart

d. Bone marrow

e. Pancreas

201. Which of the following diseases

is appropriately treated with

combined heart-lung transplantation?

a. Primary pulmonary hypertension

b. Cystic fibrosis

c. End-stage emphysema

d. Idiopathic dilated cardiomyopathy

with long-standing secondary pulmonary

hypertension

e. End-stage pulmonary fibrosis secondary

to sarcoidosis

124 Surgery

202. Which of the following is

true regarding successful wholeorgan

pancreas transplantation in

type I diabetes?

a. It results in maintenance of normal

serum glucose levels

b. Recurrence of diabetic nephropathy

in simultaneously transplanted

kidneys is not prevented

c. Oral glucose tolerance tests remain

abnormal

d. The pathologic changes of diabetic

retinopathy are reversed

e. The rate of diabetic ulcers and

amputations in the lower extremities

is reduced

203. Which of the following is

true regarding bone marrow transplantation?

a. Marrow is highly immunogenic

and easily rejected by the nonimmunosuppressed

host

b. Marrow transplantation has not

been successful in the treatment of

aplastic anemias

c. Marrow transplantation has not

been successful in the treatment of

congenital immunodeficiency diseases

d. Marrow transplantation can be

used as a successful therapy for

stage IV breast cancer following

high-dose chemotherapy

e. Marrow transplantation must be

performed with low-level immunosuppression

to enhance the degree

of chimerism

204. Which of the following statements

is true of the major histocompatibility

complex (MHC)

proteins?

a. Only nonnucleated cells express

MHC class I proteins

b. B lymphocytes, antigen-presenting

cells, and vascular endothelium

express only MHC class II proteins

c. MHC class I proteins are encoded

by the HLA-D locus (DR, DP, and

DQ)

d. MHC class I proteins act as the

major targets for antibody-mediated

rejection of organ allografts and are

detected by cross-matching techniques

e. B cells recognize antigens bound to

MHC class II proteins

205. The most useful serum

marker for detecting recurrent disease

after treatment of nonseminomatous

testicular cancer is

a. Carcinoembryonic antigen (CEA)

b. α-fetoprotein (AFP)

c. Prostate-specific antigen (PSA)

d. CA125

e. p53 oncogene

Transplants,Immunology,and Oncology 125

206. An edentulous 72-year-old

man with a 50-year history of cigarette

smoking presents with a nontender,

hard mass in the lateral

neck. The simplest way to establish

an accurate histological diagnosis

of a neck mass suspected to be cancerous

a. Fine needle aspiration cytology

b. Bone marrow biopsy

c. Nasopharyngoscopy

d. CT scan of the head and neck

e. Sinus x-ray

207. Which of the following is

true regarding intravenous administration

of chemotherapy?

a. Subcutaneous extravasation of carmustine

(BCNU) or 5-fluorouracil

(5-FU) usually causes ulceration

b. Extravasation of doxorubicin rarely

causes serious ulceration because

the agent binds quickly to tissue

nucleic acid

c. Serious and progressive ulceration

can be expected following extravasation

of vincristine or vinblastine

d. Problems of wound healing should

be anticipated if systemic 5-FU

therapy is begun less than 2 wk

postoperatively

e. Administration of folinic acid prevents

most of the toxicity of

methotrexate, but does not help to

normalize wound healing

208. For which of the following

malignancies does histologic grade

best correlate with prognosis?

a. Lung cancer

b. Melanoma

c. Colonic adenocarcinoma

d. Hepatocellular carcinoma

e. Soft tissue sarcoma

126 Surgery

209. A mother notices an abdominal mass in her 3-year-old son while giving

him a bath. There is no history of any symptoms, but the boy's blood

pressure is elevated at 105/85 mm Hg. Metastatic workup is negative and

the patient is explored. The mass below is found within the left kidney.

Which of the following statements concerning this disease is correct?

Transplants,Immunology,and Oncology 127

a. This tumor is associated with aniridia, hemihypertrophy, and cryptochidism

b. The majority of patients present with an asymptomatic abdominal mass and

hematuria

c. Treatment with surgical excision, radiation, and chemotherapy results in survival

of less than 60% even in histologically low-grade tumors

d. Surgical excision is curative and no further treatment is ordinarily advised

e. This tumor is the most common malignancy in childhood

210. An 11-year-old girl presents to your office because of a family history

of medullary carcinoma of the thyroid. Physical examination is normal.

Which of the following tests would you perform?

a. Urine vanillylmandelic acid (VMA) level

b. Serum insulin level

c. Serum gastrin level

d. Serum glucagon level

e. Serum somatostatin level

211. A 37-year-old woman has

developed a 6-cm mass on her

anterior thigh over the past 10 mo.

The mass appears to be fixed to the

underlying muscle, but the overlying

skin is movable. The next most

appropriate step in management is

a. Above-knee amputation

b. Excisional biopsy

c. Incisional biopsy

d. Bone scan

e. Abdominal CT scan

212. A 50-year-old man is incidentally

discovered to have non-

Hodgkin's lymphoma confined to

the submucosa of the stomach during

esophagogastroduodenoscopy

for dyspepsia. Which of the following

statements is true regarding his

condition?

a. Surgery alone cannot be considered

adequate treatment

b. Combined chemotherapy and radiation

therapy, without prior resecton,

are not effective

c. Combined chemotherapy and radiation

therapy, without prior resection,

result in a high risk of severe

hemorrhage and perforation

d. Outcome (freedom from progression

and overall survival) is related

to the histological grade of the

tumor

e. The stomach is the most common

site for non-Hodgkin's lymphoma

of the gastrointestinal tract

213. Interferons are correctly

characterized by which of the following

statements?

a. They are a group of complex phospholipids

b. They are produced by virus-infected

cells

c. They enhance viral replication

d. They cause Burkitt's lymphoma cell

lines to divide

e. They have not been effective in the

treatment of hairy cell leukemias

214. Which of the following statements

regarding malignant parotid

tumors is correct?

a. Acinar carcinoma is a highly aggressive

malignant tumor of the

parotid gland

b. Squamous carcinoma of the parotid

gland exhibits only moderately

malignant behavior

c. Regional node dissection for occult

metastases is not indicated for

malignant parotid tumors because

of their low incidence and the morbidity

of lymphadenectomy

d. Facial nerve preservation should be

attempted when the surgical margins

of resection are free of tumor

e. Total parotidectomy (superficial

and deep portions of the gland) is

indicated for malignant tumors

128 Surgery

215. Which of the following

potentially operable complications

is a common occurrence among

patients receiving systemic chemotherapy?

a. Acute cholecystitis

b. Perirectal abscess

c. Appendicitis

d. Incarcerated femoral hernia

e. Diverticulitis

216. Which of the following statements

regarding testicular cancer is

true?

a. Lymph node dissection after radical

orchiectomy is useful for staging

but does not increase survival

b. Seminomas and choriocarcinomas

are best treated with orchiectomy

and retroperitoneal lymph node

dissection

c. Seminomas are extremely resistant

to radiotherapy

d. Orchiectomy for a testicular mass is

approached via the scrotum

e. Cryptorchidism is associated with

an increased risk of testicular cancer

217. Advantages of dialysis over

renal transplantation include

a. Less expense if the treatment continues

for less than 2 years

b. Increased number of pregnancies

in female dialysis patients

c. Return of normal menses in female

dialysis patients

d. Less anemia in dialysis patients

e. Increased 1-year survival of dialysis

patients

Items 218-219

A 30-year-old primigravida

complains of headaches, restlessness,

sweating, and tachycardia.

She is 18 wk pregnant and her

blood pressure is 200/120 mm Hg.

218. Appropriate workup might

include

a. Exploratory laparotomy

b. Mesenteric angiography

c. Head CT scan

d. Abdominal CT scan

e. Abdominal ultrasonogram

219. Appropriate treatment might

consist of

a. Therapeutic abortion

b. Urgent excision of the tumor and a

therapeutic abortion

c. Phenoxybenzamine and propranolol

followed by a combined

cesarean section and excision of the

tumor

d. Metyrosine (Demser) blockade followed

by a combined cesarean section

and excision of the tumor

e. Phenoxybenzamine and propranolol

followed by a combined vaginal

delivery at term and excision of

the tumor

Transplants,Immunology,and Oncology 129

220. Which of the following statements

regarding radiation therapy

is true?

a. Damage to DNA occurs primarily

by the direct effect of ionizing radiation

b. Cellular hypoxia decreases sensitivity

to radiation

c. Cells in the S phase of the cell cycle

are most radiosensitive

d. Radiation therapy following lumpectomy

of a breast cancer provides

rates of local control equal to those

of mastectomy

e. Skin, gastrointestinal mucosa, and

bone marrow are relatively insensitive

to radiotherapy

221. Which of the following statements

regarding cancer therapy

with interleukin 2 (IL-2) is true?

a. It is a B-cell growth factor

b. It induces a major response in

patients with metastatic breast cancer

c. It induces a major response in

patients with metastatic colon cancer

d. It induces a major response in

patients with metastatic melanoma

e. It induces a major response in

patients with lymphoma

222. Which statement concerning

cancer and nutrition is correct?

a. Levels of nitrates in food and drinking

water are positively correlated

with the incidence of bladder cancer

b. Regular ingestion of vitamin D

from childhood probably inhibits

formation of carcinogens

c. Consumption of excessive amounts

of animal dietary fats is associated

with increased incidences of colon

cancer

d. Nutritional support of cancer

patients improves response of the

tumor to chemotherapy

e. Alcohol ingestion is associated with

pancreatic cancer

223. How do cardiac allografts differ

from renal allografts?

a. Cardiac allografts are matched by

HLA tissue typing and renal allografts

are not

b. Cardiac allografts can tolerate a

longer period of cold ischemia than

renal allografts

c. One-year graft survival for cardiac

allografts is substantially lower

than that for renal allografts

d. Cardiac allografts are matched only

by size and ABO blood type

e. Cyclosporine is a critical component

of the immunosuppressive

regimen for cardiac allografts but

not renal allografts

130 Surgery

Transplants,Immunology,and Oncology 131

224. Five-year survival rates in

excess of 20% may be expected following

resection of pulmonary

metastases if

a. Other organ metastases are present

b. Lung lesions are solitary

c. Local tumor recurrence is found

d. The tumor doubling time is less

than 20 days

e. The patient has received prior

chemotherapy

225. Which statement about

transmission of HIV in the health

care setting is true?

a. A freshly prepared solution of

dilute chlorine bleach will not adequately

decontaminate clothing

b. All needles should be capped

immediately after use

c. Cuts and other open skin wounds

are believed to act as portals of

entry for HIV

d. Double gloving reduces the risk of

intraoperative needle sticks

e. The risk of seroconversion following

a needle stick with a contaminated

needle is greater for HIV than

for hepatitis B

226. Regarding the risk of breast

cancer, which of the following

statements is true?

a. Breast cancer occurs more commonly

among women of the lower

social classes

b. A history of breast cancer in a firstdegree

family relative is associated

with a fourfold increase in risk

c. Women with a first birth after age

30 years have approximately twice

the risk of those with a first birth

before age 18

d. Cigarette smoking increases the

risk of breast cancer

e. Hair dyes have been shown to

increase the risk of breast cancer

227. Human immunodeficiency

virus (HIV) has been isolated from

many body fluids. Which of the following

is a major source of transmission?

a. Tears

b. Sweat

c. Semen

d. Urine

e. Breast milk

228. What is the primary toxicity

of doxorubicin (Adriamycin)?

a. Cardiomyopathy

b. Pulmonary fibrosis

c. Peripheral neuropathy

d. Uric acid nephropathy

e. Hepatic dysfunction

229. What is the most common

cause of cancer death among

women?

a. Breast cancer

b. Ovarian cancer

c. Colon cancer

d. Endometrial cancer

e. Lung cancer

230. Which of the following

agents causes hemorrhagic cystitis?

a. Bleomycin

b. 5-fluorouracil

c. Cisplatin

d. Vincristine

e. Cyclophosphamide

231. What is the major barrier to

successful transplantation across

animal species (xenotransplantation)?

a. Acute rejection

b. Chronic rejection

c. Hyperacute rejection

d. Infection

e. ABO incompatibility

232. Which of the following are

efficient antigen-presenting cells

found in the epidermis?

a. Macrophages

b. T cells

c. Langerhans cells

d. Dendritic cells

e. B cells

132 Surgery

233. Which of the following statements

is true regarding carcinoembryonic

antigen (CEA)?

a. CEA is an accurate screening test

for primary colorectal cancer

b. CEA levels have not been helpful in

the diagnosis of recurrent colorectal

cancer

c. CEA levels, when elevated, are

highly specific for colon cancer

d. CEA is present in normal colonic

mucosa

e. Postoperative CEA assay is 70%

accurate in predicting the appearance

of liver metastases within 1

year

DIRECTIONS: Each group of questions below consists of lettered

options followed by numbered items. For each numbered item, select the

appropriate lettered option(s). Each lettered option may be used once,

more than once, or not at all. Choose exactly the number of options

indicated following each item.

Items 234-236

For each stage in the treatment

of the patient below, select the

appropriate next step.

a. Left hemicolectomy

b. Right hemicolectomy

c. Subtotal colectomy

d. Total colectomy

e. Hepatic wedge resection

f. External beam irradiation

g. 5-fluorouracil and leucovorin

h. External beam irradiation and

chemotherapy

i. Abdominal MRI

j. No further treatment

234. A 65-year-old man is admitted

to the hospital with complaints

of intermittent constipation and

microcytic anemia. Barium enema

reveals a nonobstructing "applecore"

lesion of the proximal sigmoid

colon. Colonoscopy confirms

the location of the mass and reveals

no other synchronous lesions.

(SELECT 1 STEP)

235. The patient undergoes

surgery and recovers uneventfully.

Pathology of the resected specimen

is reported as Dukes C with negative

surgical margins. (SELECT 1

STEP)

236. In 6-mo follow-up an abdominal

CT scan shows a 2-cm isolated

lesion in the right lobe of the

liver. Repeat colonoscopy shows no

evidence of recurrent or metachronous

lesions. Chest x-ray and bone

scan are normal. (SELECT 1

STEP)

Transplants,Immunology,and Oncology 133

Items 237-240

A 32-year-old man with diabetic

nephropathy undergoes an

uneventful renal transplant from

his sister (two-haplotype match).

His immunosuppressive regimen

includes azathioprine, steroids, and

cyclosporine. For each development

in the postoperative period, select

the most appropriate next step.

a. Begin gancyclovir

b. Administer steroid boost

c. Withhold steroids

d. Decrease cyclosporine

e. Increase cyclosporine

f. Decrease azathioprine

g. Obtain renal ultrasound

h. Begin broad-spectrum antibiotics

i. Administer filgrastim (Neupogen)

j. Administer FK50

237. On postoperative day 3 the

patient is doing well, but you

notice on his routine laboratory

tests that his white blood cell count

is 2.0. (SELECT 1 STEP)

238. The patient's WBC count

gradually returns to normal, but on

postoperative day 7 he develops a

fever of 39.44°C (103°F) and a

nonproductive cough. A chest xray

reveals diffuse interstitial infiltrates,

and a "buffy coat" is positive

for viral inclusions. (SELECT 1

STEP)

239. The patient recovers from the

above illness and is discharged

home on postoperative day 18. At

3-mo follow-up he is doing well,

but you notice that his creatinine is

2.8 mg/dL. He has no fever, his

graft is not tender, and his renal

ultrasound is normal. (SELECT 1

STEP)

240. Six months following his

transplant, the patient begins to

develop fever, malaise, and pain of

the right lower quadrant. Upon palpation,

the graft is tender. Chest xray

and urine and blood cultures

are normal. Renal ultrasound shows

an edematous graft. (SELECT 1

STEP)

134 Surgery

TRANSPLANTS,

IMMUNOLOGY,AND

ONCOLOGY

Answers

186. The answer is c. (Greenfield, 2/e, pp 113-114.) Tumor necrosis factor

(TNF) is a peptide hormone produced by endotoxin-activated monocytes/

macrophages and has been postulated to be the principal cytokine

mediator in gram-negative shock and sepsis-related organ damage. Biologic

actions of TNF include polymorphonuclear neutrophil (PMN) activation

and degranulation; increased nonspecific host resistance; increased

vascular permeability; lymphopenia; promotion of interleukins 1, 2, and 6;

capillary leak syndrome; microvascular thrombosis; anorexia and cachexia;

and numerous other protective and adverse effects in sepsis. Its role in sepsis

is providing a fertile field for research in critical care.

187. The answer is b. (Greenfield, 2/e, pp 553-554.) The purpose of a

cross-match is to determine whether the recipient has circulating antibodies

against donor HLA antigens. Such antibodies do not occur naturally, but

rather are the result of prior sensitization during pregnancy, blood transfusions,

or previous transplantation. A complement-dependent lymphocytotoxicity

cross-match is performed by adding recipient serum and

complement to donor cells (T cells, B cells, or monocytes). If specific antidonor

antibodies are present, antibody binding results in complement fixation

and cell lysis. This is detected by addition of a vital dye, which is

taken up by the damaged cell membrane, resulting in a positive crossmatch.

If a positive cross-match is detected to donor T cells (HLA class I),

transplantation will result in hyperacute rejection.

188. The answer is a. (Greenfield, 2/e, pp 114-115.) Interleukin 1 (IL-1)

is a thymocyte mitogen produced by activated macrophages as well as

many other types of cells (e.g., monocytes, dendritic cells, Langerhans

cells, neutrophils, microglial cells). It induces interleukin 2 production by

135

the helper T cell, which initiates a cascade of immunoregulatory and

inflammatory functions.

189. The answer is b. (Greenfield, 2/e, pp 529-546.) Unlike the granulocyte

line, T lymphocytes express the T-cell receptor. This receptor imports

antigen specificity to T cells. The helper T cell, when stimulated by interleukin

1 and antigens, produces various lymphokines that ultimately produce

effector cells. One of these effector cells is the cytotoxic T cell, which

kills cells that express specific antigens, including viral, tumor, and nonbiologic

antigens. Macrophages and natural killer cells have some tumoricidal

activity; however, this is not specific for tumors.

190. The answer is d. (Greenfield, 2/e, pp 548-549.) Cyclosporine is a

highly effective immunosuppressive agent produced by fungi. It is more

specific than the anti-inflammatory agents such as steroids or the antiproliferative

agents such as azathioprine. The effectiveness of cyclosporine in

preventing allograft rejection is related to its ability to inhibit interleukin 2

production. Without interleukin 2 from helper T cells, there is no clonal

expansion of alloantigen-directed cytotoxic T cells and no stimulation of

antibody production by B cells.

191-192. The answers are 191-c, 192-c. (Greenfield, 2/e, pp 571-581.)

Hemodialysis, rather than management by dietary manipulation alone,

should be instituted in patients with end-stage renal failure whose serum

creatinine is over 15 mg/dL or whose creatinine clearance is less than 3

mL/min. It is important that hemodialysis be initiated prior to the onset of

uremic complications. These complications include hyperkalemia, congestive

heart failure, peripheral neuropathy, severe hypertension, pericarditis,

bleeding, and severe anemia. The uremic hyperkalemic patient in congestive

heart failure may require emergency dialysis in addition to the standard

conservative measures, which include (1) limitation of protein intake

to less than 60 g/day and restriction of fluid intake and (2) reduction of elevated

serum potassium levels by insulin-glucose or sodium polystyrene

sulfonate (Kayexalate) enema treatment. Arteriovenous fistulas require

about 2 wk to develop adequate size and flow. While awaiting maturation,

temporary dialysis can be satisfactorily performed using either an external

arteriovenous shunt or the peritoneal cavity. Renal biopsy would be performed

in an attempt to obtain a diagnosis of the underlying renal disease.

136 Surgery

Patients who are acceptable candidates for kidney transplantation usually

should undergo this form of treatment, after they are stabilized, rather than

chronic hemodialysis, the mortality for which is now higher than for transplantation.

Despite adequate dialysis, problems of neuropathy, bone disease,

anemia, and hypertension remain difficult to manage. Compared with

chronic dialysis, transplantation restores more patients to happier and

more productive lives. It had been conjectured that, all other issues being

equal, sex matching was important in the graft survival and that a motherdaughter

graft was preferred to a father-daughter graft. Review of the current

data does not support such a conclusion. The best graft survival rates

for living related transplants-over 90% at 5 years-are obtained when all

six histocompatibility loci are identical. All family members of potential

transplant recipients should be tissue typed and the donor should be

selected on the basis of closest match, if psychological and medical evaluation

makes this feasible. With the development of cyclosporine-based

immunosuppression, cadaveric kidney graft survival has approached that

of living-related transplantation. There are some transplanters who believe

that the slight improvement with living-related kidneys does not justify the

risk to the donor and that these transplantations should no longer be performed.

193. The answer is c. (Greenfield, 2/e, pp 602-606.) Chronic graft rejection

is manifested in cardiac allografts as chronic vascular rejection of main

and intramuscular coronary arteries. Myointimal proliferation and medial

scarring result in diffuse and eccentric arterial narrowing referred to as

accelerated graft atherosclerosis. Infection remains the primary cause of

death within the first year of cardiac transplant, but accelerated graft arteriosclerosis

is the most common cause of mortality thereafter. Percutaneous

transluminal coronary angioplasty, coronary artery bypass grafting, and

retransplantation are the current options for combating this problem.

194. The answer is a. (Greenfield, 2/e, pp 553-554.) A positive crossmatch

means that the recipient has circulating antibodies that are cytotoxic

to donor-strain lymphocytes. This incompatibility, which almost always

leads to an acute humoral rejection of the graft, precludes transplantation.

Blood type matching prior to organ allograft is similar to cross-matching

prior to transfusion; O is the universal donor and AB the universal recipient.

Minor blood group factors do not appear to act as histocompatibility anti-

Transplants,Immunology,and Oncology Answers 137

gens. Matching of HLA antigens in cadaveric renal transplants may improve

graft survival, but the impact is relatively minor. While attempts are made to

pair recipient and donor by tissue typing, a two-antigen match is perfectly

acceptable and even zero-antigen matches can be transplanted with good

results. Neither hypertension nor anemia is a contraindication to transplantation;

indeed, hypertension may be cured or ameliorated following successful

transplantation. Patients with end-stage renal failure generally are

anemic and can be transfused, if necessary, intra- or postoperatively. Anemia

generally also improves following transplantation because of increased

erythropoietin production by the graft.

195. The answer is c. (Greenfield, 2/e, pp 578-581.) Hyperacute rejection

is mediated by cytotoxic antibodies with subsequent triggering of the complement,

coagulation, and kinin systems. It can occur during surgery after

the clamps are released from the vascular anastomosis and the recipient's

antibodies are exposed to the donor's passenger lymphocytes and kidney

tissue. Typically, the kidney will become swollen and pale. Hyperacute

rejection is the cause of immediate and early oliguria and biopsies should

be performed intraoperatively or early postoperatively. Hyperacute rejection

is characterized pathologically by fibrin and platelet thrombosis and

necrosis of the glomerular tufts, renal arterioles, and small arteries. Massive

polymorphonuclear infiltrate with tubular necrosis occurs 24-36 h after

transplantation. The intravascular coagulation rarely results in a systemic

coagulopathy. Careful cross-matching can test for cytotoxic antibodies.

Although plasmapheresis and cyclophosphamide can transiently decrease

the preformed antibody load, to date there exists no adequate prevention

or treatment for hyperacute rejection.

196. The answer is a. (Greenfield, 2/e, pp 599-606.) Cardiac transplantation

has become an acceptable clinical treatment modality for selected

patients with end-stage cardiac failure. Allograft survivals are now comparable

to those of cadaveric renal transplants-approximately 70% at 1 year

and 50% at 5 years as reported by the Stanford group. Although kidneys

can be safely preserved by either hypothermic storage or hypothermic perfusion

for periods up to 48 h, donor hearts protected by simple hypothermia

should be transplanted within 4 h. For this reason the usual

tissue-typing procedures used in kidney transplantation are impractical in

cardiac transplantation, and indeed there is no correlation between match

138 Surgery

and outcome. In pairing donor and recipient for heart transplants there

must be at least ABO blood group compatibility. Cyclosporine has

improved results in both cardiac and renal transplantation despite its major

drawback of dose-related nephrotoxicity. Eligibility for cardiac transplantation

has evolved from strict age criteria to more flexible guidelines based on

a patient's likelihood of surviving and resuming a normally functional life

after transplantation. Many centers, however, observe age 65 as the upper

limit for transplantation. The leading cause of death in patients surviving

more than 1 year after transplantation is infection, followed by graft atherosclerosis.

197. The answer is d. (Greenfield, 2/e, pp 578-581.) The patient is experiencing

an acute rejection episode. Seventy-four percent of all acute rejection

episodes occur between 1 and 6 mo after transplantation. For cadaveric renal

transplant recipients, 63% of patients will never have an acute rejection

episode, 17% will have only one rejection episode, and 19% will have two or

more rejections. In order to grade the rejection as well as to follow the

response to treatment, a percutaneous renal biopsy should be performed.

The three treatment modalities used for acute rejection are high-dose steroids

alone, high-dose steroids plus antilymphocyte globulin (equine serum

hyperimmunized to human lymphocytes), or high-dose steroids plus OKT3

(murine monoclonal antibody to the human CD3 complex).

198. The answer is b. (Greenfield, 2/e, pp 552-553, 560.) Overall, 30% of

all infections contracted in the posttransplant period are viral. The most

common viral infections are DNA viruses of the herpesvirus family and

include cytomegalovirus (CMV), Epstein-Barr virus, herpes simplex virus,

and varicella zoster virus. CMV infections may occur as either primary or

reactive infections and have a peak incidence at about 6 wk post transplant.

The classic signs include fever, malaise, myalgia, arthralgia, and leukopenia.

CMV infection can affect several organ systems and result in pneumonitis;

ulceration and hemorrhage in the stomach, duodenum, or colon;

hepatitis; esophagitis; retinitis; encephalitis; or pancreatitis. The risk of

developing posttransplant CMV depends on donor-recipient serology, with

the greatest risk in seronegative patients who receive organs from seropositive

donors. Pyelonephritis, cholecystitis, intraabdominal abscesses, and

parotitis are caused by bacterial infections or GI perforation and not primarily

by CMV infection.

Transplants,Immunology,and Oncology Answers 139

199. The answer is b. (Greenfield, 2/e, pp 548-553.) With the introduction

of cyclosporine in the early 1980s and the rapidly accumulated experience

with liver transplantation, graft and patient survivals have improved

markedly. In the azathioprine and steroid era, 1-year graft survival was in

the range of 25%. More recently, most centers are experiencing 1-year graft

survival rates of approximately 80%.

200. The answer is d. (Greenfield, 2/e, p 553.) Donor-type lymphoid cells

transplanted within a graft may recognize the host's tissue as foreign and

mount an immune response against the host. This response, termed graftversus-

host disease (GVHD), is common in bone marrow transplantation

and is an important source of morbidity and mortality. Treatment requires

more aggressive immunosuppression. Current clinical practice includes

depletion of lymphocytes from the marrow graft in order to prevent the

development of GVHD. GVHD has been documented following liver transplantation,

presumably because of the large amount of lymphoid tissue in

the donor liver. GVHD has not been described following heart, lung, pancreas,

or kidney transplantation.

201. The answer is d. (Greenfield, 2/e, pp 606-615.) Many causes of endstage

lung disease have been appropriately treated with lung transplantation.

Whether one lung or both lungs are replaced at the time of

transplantation depends on recipient factors. Patients with restrictive

processes like primary pulmonary fibrosis do well with a single lung transplant.

For patients with primary pulmonary hypertension, unloading of

the right ventricle with single lung transplantation has been adequate and

replacement of both lungs has not been necessary in most cases. Cystic

fibrosis patients do well after lung transplantation but double lung transplant

is frequently necessary because of chronic infections. Secondary pulmonary

hypertension is due to left ventricular failure with concomitant

increases in pulmonary pressures secondary to increases in left ventricular

end-diastolic pressures. Reactive secondary pulmonary hypertension is

best treated with heart transplantation. Long-standing secondary pulmonary

hypertension that is chiefly fixed is best treated with combined

heart-lung transplantation.

202. The answer is d. (Greenfield, 2/e, pp 615-627.) Whole-organ pancreas

transplantation is the only therapy for type I insulin-dependent dia-

140 Surgery

betes that maintains normal serum glucose levels and normal glucose tolerance

tests. When the pancreas is transplanted along with a kidney, the tight

glucose control generally prevents the recurrence of diabetic nephropathy.

No series has shown the reversal of diabetic retinopathy or reduction in the

rate of diabetic ulcers or of amputations, although some parameters of diabetic

retinopathy may improve after pancreas transplantation.

203. The answer is a. (Sabiston, 15/e, pp 501-502.) Bone marrow cells

are highly immunogenic. Successful engraftment requires the use of powerful

immunosuppressants that permit the transplanted cells not only to

survive the host's immune response, but also to mount a graft-versus-host

response against recipient tissues. The graft-versus-host response is the

major impediment to more widespread clinical use of this technique.

Despite these barriers, human bone marrow transplantation has had

important clinical application in the treatment of aplastic anemias and congenital

immunodeficiency diseases and several hematologic malignancies.

Stem cell transplantation involves harvesting of a patient's own pleuripotent

bone marrow cells and subsequent reestablishment of the marrow following

high-dose, toxic chemotherapy for advanced cancer. This modality

has been used in the treatment of recurrent breast cancer, but recent metaanalyses

of the results have failed to show any significant survival benefit.

In experimental models, work with bone marrow transplantation for the

induction of tolerance to organ allografts has proved highly promising.

This may provide a key for the development of treatment protocols in

organ transplant recipients that would avoid or reduce the need for toxic

systemic immunosuppressants.

204. The answer is d. (Schwartz, 7/e, pp 366-368.) Major histocompatibility

complex (MHC) proteins are polymorphic cell surface molecules that

are important in lymphocyte-lymphocyte and lymphocyte-target interactions.

All nucleated cells express MHC class I proteins. B lymphocytes,

macrophages, antigen-presenting cells, vascular endothelium, and activated

T lymphocytes express both MHC class I and class II. MHC class I

proteins are encoded by the HLA-A, B, and C loci, and MHC class II proteins

are encoded by the HLA-D locus. Classically, MHC class I molecules

with a bound antigen are recognized by the T-cell receptor on CD81 cells,

and MHC class II molecules with a bound antigen are recognized by the

T-cell receptor on CD41 cells.

Transplants,Immunology,and Oncology Answers 141

205. The answer is b. (Schwartz, 7/e, pp 323-324.) In following patients

with nonseminomatous testicular tumors, elevated serum levels of the β

subunit of human chorionic gonadotropin (hCG), α-fetoprotein, and lactic

dehydrogenase have been found to be useful indicators of tumor activity or

recurrence. The discovery of prostate-specific antigen has recently been

touted as a major breakthrough in screening for prostate cancer, though

some clinicians feel that early diagnosis may have no impact on survival in

this disease. CA125 has been used to follow ovarian cancers; it is fairly

nonspecific but can alert the physician to the need for a more aggressive

search for persistent disease when relative increases are noted in a patient

after therapy. The p53 oncogenes have been found in soft tissue sarcomas,

osteogenic sarcomas, and colon cancers. Their significance is unknown.

206. The answer is a. (Schwartz, 7/e, pp 329-331.) Isolated enlarged cervical

lymph nodes in the adult are malignant nearly 80% of the time

(excluding benign tumors of the thyroid gland). They are usually metastatic

squamous cell carcinomas arising from primary sources above the clavicles

in the aerodigestive tract. Fine-needle aspiration cytology is commonly used

to obtain histological confirmation of suspected cancer. Aspiration cytology

can usually diagnose carcinoma accurately, but lymphoma may be difficult

to identify by this method, and open biopsy is often necessary. Bone marrow

biopsy is not indicated prior to lymph node biopsy. It is done as part of the

staging process after a diagnosis of lymphoma has been made. Endoscopy

and scanning of the oro- and nasopharynx are part of the diagnostic workup

of a suspected malignant cervical lymph node, but do not provide histological

proof of cancer.

207. The answer is d. (Schwartz, 7/e, pp 277-278, 348.) Since

chemotherapy is generally most effective in killing rapidly dividing cells,

the rapidly dividing cells of a fresh surgical wound should be in jeopardy

when chemotherapy is given in the early postoperative period. Each of the

phases of normal wound healing is theoretically at risk from one or another

class of chemotherapeutic agents. Immediately following wounding, inflammation

and vascular permeability lead to fibrin deposition and polymorphonuclear

neutrophil (PMN), monocyte, and platelet influx. Macrophages

are attracted by the activated complement system. By the fourth day the

proliferative phase begins, and for the next 20 days fibroblasts produce

mucopolysaccharides and collagen. Cross-linking of the collagen fibers

142 Surgery

then continues for several months in the maturation phase. It seems logical

to delay antineoplastic agents for 10-14 days unless there are compelling

clinical indications (e.g., superior vena cava syndrome) for more urgent

treatment. Administration of folinic acid simultaneously with methotrexate

normalizes wound healing. Extravasation of chemotherapeutic agents

during intravenous administration may result in severe ulceration and

sloughing. The nature of the injury is largely related to the nucleic-acidbinding

characteristics of the agent. Those agents that do not bind to tissue

nucleic acid (vincristine, vinblastine, nitrogen mustard, BCNU, 5-FU) generally

cause only local damage from the immediate injury. These substances

are quickly metabolized or inactivated, and usual patterns of wound healing

can be expected. On the other hand, agents that bind the nucleic acid

(doxorubicin, dactinomycin, mitomycin C, mithramycin, and daunorubicin)

cause not only immediate toxic reaction in the tissues but, unless

excised, continuing and progressive tissue damage. Though some authors

have reported success with elevation and ice packs, most recommend surgical

excision if there is severe pain, any sign of early necrosis, or significant

blistering.

208. The answer is e. (Schwartz, 7/e, pp 320-324.) The management of

malignant tumors may be guided by knowledge obtained by grading and

staging the tumors. Histologic grading reflects the degree of anaplasia of

tumor cells. Tumors in which histologic grading seems to have prognostic

value include soft tissue sarcoma, transitional cell cancers of the bladder,

astrocytoma, and chondrosarcoma. Grading has been of little predictive

value in melanoma, hepatocellular carcinoma, or osteosarcoma. Staging is

based on the extent of spread rather than histologic appearance and is more

relevant in predicting the course of lung and colorectal cancers.

209. The answer is a. (Schwartz, 7/e, pp 1747-1748.) This is a nephroblastoma

(Wilms tumor) adherent to the left kidney. These tumors are associated

with aniridia (rarely) and with hemihypertrophy, cryptorchidism, or

hypospadias in about 10% of cases. Most patients present with an asymptomatic

mass found by a parent. Less than one-third of patients experience

hematuria. As would be expected in over half such cases, this child is

hypertensive, probably due to compression of the renal artery by the mass.

Treatment with excision, radiation, vincristine, and actinomycin D results

in survival rates of over 90% in stage I and II tumors. While computed

Transplants,Immunology,and Oncology Answers 143

tomography (CT) or magnetic resonance imaging (MRI) evaluates metastatic

disease, intravenous pyelography (IVP) is better at differentiating this

tumor from polycystic kidney or neuroblastoma. Wilms tumor is the most

common abdominal malignancy of childhood, but represents only about

10% of childhood malignant tumors.

210. The answer is c. (Schwartz, 7/e, pp 1686-1688.) Medullary carcinomas

occur in families as part of syndromes called multiple endocrine neoplasia

(MEN) type 2A and type 2B. MEN 2A consists of multicentric

medullary thyroid cancer, pheochromocytomas or adrenal medullary

hyperplasia, and hyperparathyroidism. MEN 2B consists of medullary cancer,

pheochromocytoma and mucosal neuromas, gangliomas, and a Marfanlike

habitus. These patients may develop medullary carcinoma at a very

young age, and any patient with MEN 2B should be assumed to have

medullary cancer until proved otherwise. Patients are followed carefully for

pheochromocytoma with urine VMA, for hyperparathyroidism with serum

calcium, and for medullary carcinoma with serum calcitonin. However, as

some patients have a normal basal calcitonin, a pentagastrin or provocative

calcium infusion test should be performed in these high-risk patients.

Patients thought to have MEN 1 syndrome (pituitary, parathyroid, and

pancreatic tumors) or Zollinger-Ellison syndrome should be assayed for

serum gastrin, insulin, glucagon, and somatostatin. These assays may

prove to be inappropriately high in MEN 1 syndrome due to pancreatic

islet cell tumors.

211. The answer is c. (Schwartz, 7/e, pp 334-335.) Benign soft tissue

tumors far outnumber their malignant counterparts. Because of this, prolonged

delays are common before definitive treatment of soft tissue sarcomas

is instituted. Risk for malignancy is increased for tumors greater than

5 cm in largest diameter, as well as for those lesions that are symptomatic

or have enlarged rapidly over a short period of time. Properly performed

biopsy is critical in the initial treatment of any soft tissue mass. Improperly

performed biopsies can complicate the care of the sarcoma patient, and in

rare circumstances even eliminate certain surgical options. Excisional biopsies

should be reserved for small masses for which complete excision

would not jeopardize subsequent treatment should a sarcoma be found.

For all other masses incisional biopsy should be performed. The incision

144 Surgery

should be placed directly over the mass and should be oriented along the

long axis of the extremity.

212. The answer is e. [Tondini, Ann Oncol 4(10):831-837, 1993. Gobbi,

Cancer 65(11):2528-2536, 1990.] The stomach is the most common site in

the gastrointestinal tract for non-Hodgkin's lymphoma, followed by the

small intestine and the colon. Lymphomas constitute 3% of all malignant

gastric tumors. Ninety percent of these lymphomas are of the non-

Hodgkin's type. Surgery alone can be considered adequate treatment for

patients with non-Hodgkin's lymphoma that does not infiltrate beyond the

submucosa. However, gastric resection is not considered mandatory, and

there are no substantial differences in response to therapy and survival

when resection is compared with combined chemotherapy and radiation

therapy, including in advanced cases. Moreover, chemotherapy and radiation

therapy have been shown to be effective even in unresected bulky

cases, and provide minimal risk of hemorrhage and perforation even in this

setting.

213. The answer is b. (Schwartz, 7/e, pp 349-350.) The interferons are a

group of glycoproteins first found as products of virus-infected cells that

inhibited viral replication. Subsequently, they have been shown to have a

variety of effects both on cells of the immune system and on malignant

cells. Interferons cause Burkitt's lymphoma cell lines to differentiate and

lose the capacity to divide. Hematologic malignancies are very responsive

to interferons; up to 100% of hairy cell leukemias show some degree of

remission. Interferon α has been used in the treatment of chronic active

hepatitis B and C with promising results in recent clinical trials.

214. The answer is d. (Schwartz, 7/e, pp 656-662.) Acinar, adenoid cystic,

and low grades of mucoepidermoid carcinomas exhibit moderately

malignant behavior. Undifferentiated, squamous, and high grades of

mucoepidermoid carcinomas are considered highly malignant tumors.

Regional node dissection is indicated for malignant tumors because of the

high (up to 50%) incidence of occult regional metastases. Facial nerve

preservation should be attempted when the margins are adequate and the

tumor is well localized. The minimal appropriate procedure for parotid

carcinoma is a superficial parotidectomy with nerve preservation. The

Transplants,Immunology,and Oncology Answers 145

nerve must be partially or totally sacrificed if the tumor directly involves

the nerve trunk or its branches.

215. The answer is b. (Schwartz, 7/e, pp 347-348.) A surgeon is frequently

asked to evaluate patients who are receiving systemic chemotherapy. Most

complications of chemotherapy do not require surgical therapy. Perirectal

abscesses are more common in these immunosuppressed patients. Gastrointestinal

bleeding occurs secondary to mucosal irritation and thrombocytopenia.

Pancreatitis is uncommon, but is associated with L-asparaginase use. Up

to 20% of patients treated with floxuridine by continuous hepatic artery infusion

develop some degree of inflammation and obstruction of the bile duct.

Systemic chemotherapy does not increase the likelihood of acute cholecystitis,

appendicitis, incarcerated femoral hernia, or diverticulitis.

216. The answer is e. (Schwartz, 7/e, pp 1794-1795.) After radical

orchiectomy, lymph node dissection is indicated in embryonal carcinoma,

teratocarcinoma, and adult teratoma if there is no supradiaphragmatic

spread. This dissection increases the 5-year survival and helps in staging.

Seminoma is extremely radiosensitive and lymph node dissection is unnecessary.

Choriocarcinoma is associated with pulmonary metastases in 81% of

cases and is treated with chemotherapy. Orchiectomy for a testicular mass is

approached via an inguinal incision in order to perform a high ligation of

the cord and to eliminate spread of the tumor. Cryptorchidism (undescended

testicle) is associated with decreased spermatogenesis and carries a

lifelong risk of malignant degeneration even after being surgically corrected.

217. The answer is a. (Greenfield, 2/e, pp 237-238, 571-572.) Dialysis is

less expensive than renal transplantation if the graft functions for less than

2 years. Recipients with functioning grafts are less anemic because of erythropoietin

production by the graft. As more dialysis patients are treated

with recombinant erythropoietin, this advantage may disappear. Transplanted

females have more normal menses and an increased number of

successful pregnancies. The patient survival in the two groups is comparable

at 1 year.

218-219. The answers are 218-e, 219-e. (Schwartz, 7/e, pp

1646-1649.) This young pregnant woman presents with the symptoms of a

pheochromocytoma. These tumors can initially become symptomatic dur-

146 Surgery

ing pregnancy. A noninvasive workup should be performed. Ultrasonography

of the abdomen is frequently sufficient to localize the tumor to the

right or left adrenal; an abdominal CT scan with its large dose of radiation

should be avoided in pregnancy. The treatment can be early excision of the

pheochromocytoma, and in three cases in pregnant women this was done

with survival of two of the three infants. A therapeutic abortion, especially

at 18 wk, is not indicated, and cesarian section would not produce a viable

fetus. The current approach is α- and β-adrenergic blockade followed by

vaginal delivery or cesarean section with excision of the tumor at the same

time as delivery or electively after delivery. Metyrosine (Demser) inhibits

tyrosine hydroxylase and results in a decrease in endogenous levels of catecholamines.

This form of treatment, coupled with term delivery, is also

acceptable.

220. The answer is b. (Greenfield, 2/e, pp 491-495.) Only about 30% of

the biologic damage from x-rays is due to the direct effects on the target

molecule. The remainder is due to an indirect action mediated by free radicals

and can be modified by free radical scavengers such as sulfhydryl. The

percentage of cells killed by a given dose of x-rays or gamma rays is greatly

increased by molecular oxygen; cells deficient in oxygen are resistant to

radiation. Among the basic principles of radiation biology is the observation

that the sensitivity of mammalian cells to radiation varies with their

position in the cell division cycle. M phase (mitotic phase) cells are the

most radiosensitive. Radiation is frequently employed for local control of

disease. Survival rates for breast lumpectomy and radiation are equal to

those of mastectomy, but local control rates (10-15% recurrence at 10

years for stage I and II cancers treated with lumpectomy and radiation versus

approximately 5% treated with mastectomy) are nevertheless inferior.

Rapidly dividing cells of the gastrointestinal mucosa and bone marrow are

particularly sensitive to the effects of radiation.

221. The answer is d. (Schwartz, 7/e, pp 349-351.)With the availability of

recombinant interleukin-2, multiple trials of cancer therapy with this lymphokine

have been undertaken. The most successful trials have documented

complete or partial responses in patients with metastatic renal cell

carcinoma and melanoma. However, IL-2 therapy has been ineffective in the

treatment of breast cancer, colon cancer, and lymphoma. The therapy is not

innocuous. All patients exhibit a marked lymphocytosis, eosinophilia, fluid

Transplants,Immunology,and Oncology Answers 147

retention, fever, and decrease in peripheral vascular resistance, effects similar

to those of septic shock.

222. The answer is c. (Heys, Br J Surg 79:614-623, 1992.) Malignant

tumors require energy substrates to grow and ordinarily claim these substrates

from the host. In animal studies, withholding dietary proteins diminishes

the rate of tumor growth. There is no evidence in the human to suggest

acceleration of tumor growth when nutritional support is provided. There is

also no evidence that nutritional therapy improves the response of the tumor

to therapy. For nearly a century, the association of stomach cancer and diet

has been recognized. Among the wide variety of substances incriminated are

nitrates and nitrosamides in food and drinking water. There is evidence that

regular ingestion of vitamin C from childhood may reduce the formation of

carcinogens, though reduction in the incidence of cancer has not been

demonstrated. Excess amounts of dietary fat and deficiency of fiber have

been clearly associated with colon cancer. Animal fats have also been associated

with cancer of the exocrine pancreas, the prostate, and the

endometrium. Alcohol consumption, especially when combined with cigarette

smoking, increases the incidence of esophageal cancer. Consumption of

alcohol also increases the incidence of pancreatitis, but not pancreatic cancer.

223. The answer is d. (Greenfield, 2/e, pp 599-606.) Cardiac allograft has

become an accepted treatment for end-stage heart disease. One-year cardiac

allograft survival approaches 90% and is equivalent to 1-year renal

allograft survival. Cardiac allografts have a cold ischemia preservation time

of 4-5 h and therefore tissue typing is not practical. Cardiac donors are

matched to recipients only by size and ABO blood type. Tissue typing

remains an important component of cadaveric kidney allograft matching.

The mainstay of immunosuppression for both cardiac and renal allografts

continues to include cyclosporine, azathioprine (Imuran), and steroids.

224. The answer is b. (Schwartz, 7/e, pp 340-341, 352-353.) Resection of

metastases of lung, liver, and brain can result in occasional 5-year cures. In

general, surgery should be undertaken only when the primary tumor is

controlled, diffuse metastatic disease has been ruled out, and the affected

patient's condition and the location of the metastasis permit safe resection.

Five-year survival rates as high as 18% have been reported for selected

patients with liver metastases from colorectal primary tumors. However,

148 Surgery

the best results have come from resection of pulmonary metastases, in

which 5-year survival rates exceed those of resection for primary bronchogenic

carcinoma. Autopsy reviews have demonstrated that many

patients with pulmonary metastases have no other evidence of tumor,

which suggests that resectional treatment may be justified even when the

lung foci are not solitary. Selection of patients for pulmonary resections

may be aided by measurement of tumor doubling times; patients with doubling

times greater than 40 days appear to benefit most, while those with

doubling times less than 20 days are not significantly helped.

225. The answer is c. (Rhame, Postgrad Med 91:141-152, 1992. Wilson,

Postgrad Med 88:193-201, 1990.) The risk of contracting HIV is much less

than the risk of contracting hepatitis B from a patient. Although the risk of

transmission of HIV in the health care setting is very low, there are reported

cases of seroconversion after parenteral exposure. Particular precautions

should be taken in operating upon patients who are known to be seropositive

for HIV or who have known risk factors. Recommendations include

elimination of inexperienced personnel or personnel with open lesions on

body surfaces from the operating room. Disposable gowns, drapes, masks,

and eye shields should be used. Contaminated clothing should be soaked

in a dilute solution (1:10) of chlorine bleach prior to washing. Double

gloving does not reduce the major intraoperative risk of needle puncture,

which is the primary source of risk to the operating team. Needles should

never be capped; an uncapped needle is less dangerous than are the

maneuvers to recap needles.

226. The answer is c. (Harris et al, pp 159-167.) Risk factors for breast

cancer include family history, nulliparity, previous breast cancer, early

menarche, and late menopause. A late age at first birth (after age 30) doubles

the risk of breast cancer compared with early parity (age 18 or earlier).

Having one first-degree relative (mother, sister, or daughter) with breast

cancer also doubles the risk. Women of the upper social classes, as measured

by either education or income, have been found to have the highest

incidence of breast cancer. Neither cigarette smoking nor the use of hair

dye has been correlated with breast cancer.

227. The answer is c. (Recommendations for prevention of HIV transmission

in health care settings. NY State J Med 88:25-31, 1988. Rhame, Postgrad

Transplants,Immunology,and Oncology Answers 149

Med 91:141-144, 1992.) HIV has been isolated from blood, semen, vaginal

secretions, saliva, tears, breast milk, CSF, amniotic fluid, and urine. It is an

extremely fastidious virus that ordinarily is transmitted only after repeated

admixture of body fluids. Blood and semen are by far the major transmission

fluids.

228. The answer is a. (Greenfield, 2/e, p 502.) Doxorubicin, an antibiotic

derived from Streptomyces species, has activity against sarcomas and carcinomas

of the breast, liver, bladder, prostate, head and neck, esophagus,

and lung. Its major side effect is production of a dilated cardiomyopathy.

Patients receiving this agent should have echocardiography before and

after treatment in order to monitor potential cardiac toxicity.

229. The answer is e. (Greenfield, 2/e, pp 455-459.) Cancer remains the

second most common cause of mortality in the United States after heart

disease, accounting for 22% of all deaths. Both sexes have demonstrated

dramatic increases in the death rate observed from lung cancer from 1930

to 1990 owing to increases in cigarette smoking. Lung cancer is the leading

cause of cancer death in both men and women.

230. The answer is e. (Greenfield, 2/e, p 501.) Cyclophosphamide is an

alkylating agent used in the treatment of a variety of solid tumors. Its major

side effect is hemorrhagic cystitis. Bleomycin can cause pulmonary fibrosis.

Vincristine is an alkaloid that can cause peripheral and central neuropathies.

Cisplatin is an alkylating agent that can lead to ototoxity, neurotoxicity,

and nephrotoxicity. 5-fluorouracil is an antimetabolite that can

cause mucositis, dermatitis, and cerebellar dysfunction.

231. The answer is c. (Greenfield, 2/e, p 555.) The major barrier to successful

xenotransplantation has been hyperacute rejection, which refers to

the binding of preformed human antibodies to donor endothelial cells.

This results in the activation of complement, cell lysis, and eventually vascular

thrombosis.

232. The answer is c. (Greenfield, 2/e, p 537.) Processing and presentation

of antigen in association with class II molecules is critical for activation

of T cells. Langerhans cells are potent antigen-presenting cells (APCs)

150 Surgery

found in skin. Macrophages are the major APCs in the body. Dendritic cells

are APCs found in lymphoid tissue.

233. The answer is e. (Greenfield, 2/e, pp 1138, 1144.) CEA is a glycoprotein

that is present in early embryonic and fetal cells (an oncofetal antigen)

and in colon cancer. It is not found in normal colon mucosa. It is not

tumor specific and may be elevated in a variety of benign and malignant

conditions, including cirrhosis, ulcerative colitis, renal failure, pancreatitis,

pancreatic cancer, stomach cancer, breast cancer, and lung cancer. The

CEA assay is, however, a sensitive serologic tool for identifying recurrent

disease. In about two-thirds of patients with recurrent disease, an increased

CEA level is the first indicator of tumor reappearance. A rising CEA following

colon cancer surgery, in the absence of other conditions associated

with an elevated CEA, predicts the appearance of liver metastases within 1

year with an accuracy approaching 70%.

234-236. The answers are 234-a, 235-g, 236-e. (Greenfield, 2/e, pp

1137-1144.) The patient has a left colon cancer. In order to resect the

tumor with a margin of 3-5 cm on its proximal and distal ends as well as

to remove the draining lymph node basin, a left hemicolectomy should be

performed. A Dukes C tumor is one that extends through the bowel wall

and involves adjacent lymph nodes. In a study of 1166 patients with stage

B and C colon cancer, the National Surgical Adjuvant Breast and Bowel

Project (NSABP) reported an improved survival in patients randomized to

receive adjuvant chemotherapy compared with no further treatment after

resection. Adjuvant radiation therapy has only been useful in preventing

local recurrence in rectal cancers with positive surgical margins.

The liver is the most common site of bloodborne metastases from primary

colorectal cancers. In a subgroup of patients, the liver may be the

only site of disease. Overall, surgical resection is associated with a 25-30%

5-year survival rate.

237-240. The answers are 237-f, 238-a, 239-d, 240-b. (Greenfield,

2/e, pp 577-581.) Routine postoperative immunosuppression for a renal

transplant recipient includes cyclosporine, azathioprine, and steroids.

Cyclosporine is nephrotoxic and is frequently withheld in the postoperative

period until the creatinine returns to normal following transplantation.

Transplants,Immunology,and Oncology Answers 151

Azathioprine has bone marrow toxicity as its major side effect and both

WBC and platelet counts need to be monitored in the immediate posttransplant

period. The patient's decrease in WBCs is secondary to azathioprine

toxicity, and the most appropriate step is to decrease the dose of

azathioprine.

Viral infections are a serious cause of morbidity following transplantation.

A "buffy coat" is the supernatant of a centrifuged blood sample that

contains the WBCs. Viral cultures from this supernatant as well as localization

of inclusion bodies can identify transplant patients infected with

cytomegalovirus (CMV). This patient has CMV pneumonitis and needs to

be treated with high-dose gancyclovir.

An elevation in creatinine at 3-mo follow-up can be secondary to

rejection, anastomotic problems, urologic complications, infection, or

nephrotoxicity of various medications. With a normal ultrasound, no fever,

and no graft tenderness, the most likely cause is cyclosporine-induced

nephrotoxicity and the most appropriate step is a reduction in the

cyclosporine dose.

Finally, at 6 mo with graft tenderness, fever, and an edematous kidney

on ultrasound, rejection must be suspected. Negative cultures make infection

unlikely, and a steroid boost is appropriate. Addition of monoclonal

antibodies to CD3 (OKT3) or pooled antibodies against lymphocytes

(ALG) is also appropriate in the treatment of a first rejection.

152 Surgery

ENDOCRINE PROBLEMS

AND BREAST

Questions

DIRECTIONS: Each item below contains a question or incomplete

statement followed by suggested responses. Select the one best response to

each question.

153

241. Which of the following statements

regarding adrenal cortical

insufficiency is true?

a. Treatment with exogenous steroids

is usually ineffective

b. It is commonly seen as a consequence

of metastasis of distant cancers,

such as lung or breast, to the

adrenal glands

c. Chronic adrenal insufficiency

(Addison's disease) in the preoperative

patient should be recognizable

by a constellation of findings,

including hyperglycemia, hypernatremia,

and hypokalemia

d. Death from untreated chronic

adrenal insufficiency may occur

within hours of surgery

e. The most common underlying

cause today is infection with resistant

tuberculosis

242. The thyroid scan shown

below exhibits a pattern that is

most consistent with which of the

following disorders?

a. Hypersecreting adenoma

b. Graves' disease

c. Lateral aberrant thyroid

d. Papillary carcinoma of thyroid

e. Medullary carcinoma of thyroid

Terms of Use

243. A 17-year-old girl presents

with an anterior neck mass. Her

thyroid scan, shown below, is most

consistent with which of the following

disorders?

245. Estrogen receptor activity is

clinically useful in predicting

a. The presence of ovarian cancer

b. The presence of metastatic disease

c. Response to chemotherapy

d. Response to hormonal manipulation

e. The likelihood of development of

246. When galactorrhea occurs in

a high school student, a diagnostic

associated finding would be

a. Gonadal atrophy

b. Bitemporal hemianopia

c. Exophthalmos and lid lag

d. Episodic hypertension

e. "Buffalo hump"

247. The diagnosis of primary hyperparathyroidism

is most strongly

suggested by

a. Serum acid phosphatase above 120

IU/L

b. Serum alkaline phosphatase above

120 IU/L

c. Serum calcium above 11 mg/dL

d. Urinary calcium below 100 mg/day

e. Parathyroid hormone levels below

5 pmol/L

248. Somatostatin contributes to

which of the following processes?

a. Inhibition of adrenocortical cells

b. Inhibition of pancreatic α cells

c. Stimulation of antral gastrin cells

d. Stimulation of secretin-producing

cells in the duodenum

e. Stimulation of GI motility

154 Surgery

a. Hypersecreting adenoma

b. Parathyroid adenoma

c. Thyroglossal duct cyst

d. Graves' disease

e. Carcinoma

244. A 35-year-old woman undergoes

her first screening mammogram.

Which of the following

mammographic findings would

require a breast biopsy?

a. Breast calcifications larger than 2

mm in diameter

b. Five or more clustered breast

microcalcifications per square centimeter

c. A density that effaces with compression

d. Saucer-shaped microcalcifications

e. Multiple round well-circumscribed

breast densities

249. Which of the following

statements concerning Cushing syndrome

secondary to adrenal adenoma

is true?

a. Adrenal adenomas cause 40-60%

of all cases of Cushing syndrome

b. Biochemical and x-ray procedures

are generally unsuccessful in lateralizing

the tumors preoperatively

c. Exploration of both adrenal glands

is indicated

d. For uncomplicated tumors, an open

transperitoneal surgical approach is

usually employed

e. Postoperative corticoid therapy is

required to prevent hypoadrenalism

250. A 40-year-old woman is

found to have a 1- to 2-cm, slightly

tender cystic mass in her breast; she

has no perceptible axillary adenopathy.

What course would you follow?

a. Reassurance and reexamination in

the immediate postmenstrual period

b. Immediate excisional biopsy

c. Aspiration of the mass with cytologic

analysis

d. Fluoroscopically guided needle

localization biopsy

e. Mammography and reevaluation of

options with new information

251. Which statement concerning

radiation-induced thyroid cancer is

true?

a. It usually follows high-dose radiation

to the head and neck

b. A patient with a history of radiation

is safe if no cancer has been found

20 years after exposure

c. Approximately 25% of patients

with a history of head and neck

irradiation develop thyroid cancer

d. Most radiation-induced thyroid

cancers are follicular

e. The treatment of choice is a neartotal

(or total) thyroidectomy

252. The course of papillary carcinoma

of the thyroid is best

described by which of the following

statements?

a. Metastases are rare; local growth is

rapid; erosion into the trachea and

large blood vessels is frequent

b. Local invasion and metastases

almost never occur, which makes

the term carcinoma misleading

c. Bony metastases are frequent and

produce an osteolytic pattern particularly

in vertebrae

d. Metastases frequently occur to cervical

lymph nodes; distant metastases

and local invasion are rare

e. Rapid, widespread metastatic involvement

of the liver, lungs, and

bone marrow results in a 5-year

survival rate of approximately 10%

Endocrine Problems and Breast 155

253. Fibrocystic disease of the

breast has been associated with elevated

blood levels of

a. Testosterone

b. Progesterone

c. Estrogen

d. Luteinizing hormone

e. Aldosterone

254. A 14-year-old black girl had

her right breast removed because of

a large mass. The tumor weighed

1400 g and was found to have a

bulging, very firm, lobulated surface

with a whorl-like pattern, as

illustrated below. This neoplasm is

most likely

255. As an incidental finding during

an upper abdominal CT scan, a

3-cm mass in the adrenal gland is

noted. The appropriate next step in

analysis and management of this

finding would be

a. Observation

b. CT-guided needle biopsy

c. Excision of the mass

d. Measurement of urine catecholamine

excretion

e. Cortisol provocation test

Items 256-257

A 53-year-old woman presents

with complaints of weakness, anorexia,

malaise, constipation, and

back pain. While being evaluated,

she becomes somewhat lethargic.

Laboratory studies include a normal

chest x-ray; serum albumin 3.2

mg/dL; serum calcium 14 mg/dL;

serum phosphorus 2.6 mg/dL;

serum chloride 108 mg/dL; BUN 32

mg/dL; and creatinine 2.0 mg/dL.

256. Appropriate initial management

would include

a. Intravenous normal saline infusion

b. Administration of thiazide diuretics

c. Administration of intravenous phosphorus

d. Use of mithramycin

e. Neck exploration and parathyroidectomy

156 Surgery

a. Cystosarcoma phylloides

b. Intraductal carcinoma

c. Malignant lymphoma

d. Fibroadenoma

e. Juvenile hypertrophy

257. After appropriate immediate

management, the patient's symptoms

resolve. Diagnostic tests to

perform at this point would include

which of the following?

a. Abdominal angiogram

b. Measurement of serum gastrin hormone

levels

c. Kveim test

d. Serum and urine protein electrophoresis

e. Neck exploration

258. A woman sustains an injury

to her chest after striking the steering

wheel of her automobile during

a collision. Which of the following

statements concerning fat necrosis

of the breast is true?

a. Most patients report a history of

trauma

b. The lesion is usually nontender and

diffuse

c. It predisposes patients to the development

of breast cancer

d. It is difficult to distinguish from

breast cancer

e. Excision exacerbates the process

Items 259-260

259. The most likely diagnosis in a

patient with hypertension, hypokalemia,

and a 7-cm suprarenal

mass is

a. Hypernephroma

b. Cushing's disease

c. Adrenocortical carcinoma

d. Pheochromocytoma

e. Carcinoid

260. Appropriate treatment of this

condition would include which of

the following?

a. Embolization of the arterial blood

supply, including the suprarenal

artery

b. Metronidazole

c. Mitotane

d. Phentolamine

e. Phenoxybenzamine

261. For pregnant women who

are found to have breast cancer

a. Termination of a first-trimester

pregnancy is mandatory

b. Carcinoma of the breast behaves

more aggressively in pregnant

women owing to hormonal stimulation

c. Breast conservation is inappropriate

for third-trimester pregnancies

d. Most have hormonally sensitive

tumors

e. Administration of adjuvant

chemotherapy is safe for the fetus

during the second and third

262. True statements regarding

Paget's disease of the breast include

that it

a. Usually precedes development of

Paget's disease of bone

b. Presents with nipple-areolar eczematous

changes

c. Does not involve axillary lymph

nodes because it is a manifestation

of intraductal carcinoma only

d. Accounts for 10-15% of all newly

diagnosed breast cancers

e. Is adequately treated with wide

excision when it presents as a mass

Endocrine Problems and Breast 157

263. A 40-year-old man who has a

long history of peptic ulcer disease

that has not responded to medical

therapy is admitted to the hospital.

His serum gastrin levels are

markedly elevated; at celiotomy, a

small, firm mass is palpated in the tail

of the pancreas. Correct statements

concerning this patient's condition

include which of the following?

a. Histamine or a protein meal will

markedly increase basal acid secretion

b. Secretin administration will suppress

acid secretion

c. The pancreatic mass will probably

d. Distal pancreatectomy is the treatment

of choice

e. H2 receptor antagonists have not

been beneficial in the treatment of

this condition

264. Of the common complications

of thyroidectomy, the one that

may be avoided through prophylaxis

a. Injury to the recurrent laryngeal

nerve

b. Injury to the superior laryngeal

nerve

c. Symptomatic hypocalcemia

d. Thyroid storm

e. Postoperative hemorrhage and

wound hematoma

Items 265-266

265. Following correction of

the patient's hypercalcemia with

hydration and gentle diuresis with

furosemide, the most likely therapeutic

approach would be

a. Administration of maintenance

doses of steroids

b. Radiation treatment for bony

metastases

c. Neck exploration and resection of

three out of four parathyroid glands

d. Neck exploration and resection of a

parathyroid adenoma

e. Avoidance of sunlight, vitamin D,

and calcium-containing dairy products

266. This 30-year-old woman presented

with weakness, bone pain,

an elevated parathormone level,

and a serum calcium level of 15.2

mg/dL. Skeletal survey films were

taken, including the hand films and

chest x-ray shown. The most likely

cause of these findings is

a. Sarcoidosis

b. Vitamin D intoxication

c. Paget's disease

d. Metastatic carcinoma

e. Primary hyperparathyroidism

158 Surgery

159

267. A 25-year-old woman is

found to have an anterior neck

mass. Her thyroid scan, shown

below, exhibits findings that are

consistent with which of the following

disorders?

269. A 36-year-old woman, 20 wk

pregnant, presents with a 1.5-cm

right thyroid mass. Fine-needle

aspiration is consistent with a papillary

neoplasm. The mass is "cold"

by scan and solid by ultrasound.

Which method of treatment would

be contraindicated?

a. Right thyroid lobectomy

b. Subtotal thyroidectomy

c. Total thyroidectomy

d. Total thyroidectomy with lymph

node dissection

e. 131I radioactive ablation of the thyroid

gland

270. Correct statements concerning

Hürthle-cell carcinoma of the

thyroid include which of the following?

a. It is a form of anaplastic thyroid

cancer

b. It metastasizes via the lymphatics to

regional lymph node basins

c. Treatment consists of a near-total

(or total) thyroidectomy

d. Microscopically, it consists of clusters

of cells separated by areas of

collagen and amyloid

e. Once treated appropriately, it has a

low rate of recurrence

160 Surgery

a. Carcinoma

b. Toxic adenoma

c. Toxic multinodular goiter

d. Graves' disease

e. de Quervain's (subacute) thyroiditis

268. Incisional biopsy of a breast

mass in a 35-year-old woman

demonstrates a hypercellular

fibroadenoma (cystosarcoma phylloides)

at the time of frozen section.

Appropriate management of this

lesion could include

a. Wide local excision with a rim of

normal tissue

b. Lumpectomy and axillary lymphadenectomy

c. Modified radical mastectomy

d. Excision and postoperative radiotherapy

e. Excision, postoperative radiotherapy,

and systemic chemotherapy

271. A 28-year-old man presents

with a 2.5-cm mass in the anterior

triangle of the left neck. The mass

moves with swallowing and has

slowly enlarged over the past 1-2

years. The patient's past medical

history is notable for high-dose

irradiation to the chest and

abdomen for Hodgkin's lymphoma

8 years prior to presentation. Thyroid

scan shows a "cold" lesion.

Fine-needle aspiration cytology is

"suspicious." Core-needle biopsy

shows features suggestive of a follicular

neoplasm. True statements

regarding this patient's condition

include

a. Thyroid nodules in men are rarely

malignant

b. Prior radiation to the chest, if anything,

would diminish the risk of

subsequent thyroid cancer

c. In the setting of abnormal cytology,

an initial course of TSH suppression

by thyroid hormone is recommended

d. In the setting of a possible follicular

neoplasm, radioactive iodine (131I)

ablation is recommended

e. Total thyroidectomy is an acceptable

treatment for this patient

272. True statements about discharge

from the nipple include

a. Intermittent thin or milky discharge

can be physiologic

b. Expressible nipple discharge is an

indication for open biopsy

c. Bloody discharge is indicative of an

underlying malignancy

d. Galactorrhea is indicative of an

underlying malignancy

e. Pathologic discharge is usually bilateral

273. True statements regarding

Cushing's disease and Cushing syndrome

include which of the following?

a. Adrenocortical hyperplasia is the

most common cause of Cushing's

disease

b. Overproduction of ACTH is pathognomonic

of Cushing syndrome

c. Clinical manifestations of Cushing's

disease and Cushing syndrome are

identical

d. Cushing syndrome is caused only

by neoplasms of either the pituitary

or adrenal glands

e. Cushing's disease is incurable

Endocrine Problems and Breast 161

274. A 34-year-old woman has

recurrent fainting spells induced by

fasting. Her serum insulin levels

during these episodes are markedly

elevated. Correct statements regarding

this patient's condition

include which of the following?

a. The underlying lesion is probably

an α-cell tumor of the pancreas

b. The underlying lesion is usually

multifocal

c. These lesions are usually malignant

d. Serum calcium levels may be elevated

e. She should be screened for a coexistent

pheochromocytoma

275. The incidence of breast cancer

a. Increases with increasing age

b. Has declined since the 1940s

c. Is related to dietary fat intake

d. Is related to coffee intake

e. Is related to vitamin C intake

162 Surgery

DIRECTIONS: Each group of questions below consists of lettered

options followed by numbered items. For each numbered item, select the

appropriate lettered option(s). Each lettered option may be used once,

more than once, or not at all. Choose exactly the number of options

indicated following each item.

163

Items 276-280

For each clinical description

select the appropriate stage of

breast cancer.

a. Stage I

b. Stage II

c. Stage III

d. Stage IV

e. Inflammatory carcinoma

276. Tumor not palpable, clinically

positive lymph nodes fixed to

one another, no evidence of metastases

(SELECT 1 STAGE)

277. Tumor 5.0 cm; clinically positive,

movable ipsilateral lymph

nodes; no evidence of metastases

(SELECT 1 STAGE)

278. Tumor 2.1 cm, clinically negative

lymph nodes, no evidence of

metastases (SELECT 1 STAGE)

279. Tumor not palpable but

breast diffusely enlarged and erythematous,

clinically positive supraclavicular

nodes, and evidence of

metastases (SELECT 1 STAGE)

280. Tumor 0.5 cm, clinically negative

lymph nodes, pathological rib

fracture (SELECT 1 STAGE)

Items 281-285

A 43-year-old man presents

with signs and symptoms of peritonitis

in the right lower quadrant.

The clinical impression and supportive

data suggest acute appendicitis.

At exploration, however, a

tumor is found; frozen section suggests

carcinoid features. For each

tumor described, choose the most

appropriate surgical procedure.

a. Appendectomy

b. Segmental ileal resection

c. Cecectomy

d. Right hemicolectomy

e. Hepatic wedge resection and

appropriate bowel resection

281. A 2.5-cm tumor at the base

of the appendix (SELECT 1 PROCEDURE)

282. A 1.0-cm tumor at the tip of

the appendix (SELECT 1 PROCEDURE)

Endocrine Problems and Breast 163

283. A 0.5-cm tumor with serosal

umbilication in the ileum (SELECT

1 PROCEDURE)

284. A 1.0-cm tumor of the

midappendix; 1-cm firm, pale

lesion at the periphery of the right

lobe of the liver (SELECT 1 PROCEDURE)

285. A 3.5-cm tumor encroaching

onto the cecum and extensive liver

metastases (SELECT 1 PROCEDURE)

Items 286-290

For each clinical problem outlined,

select acceptable treatment

options.

a. No further surgical intervention

b. Wide local excision

c. Wide local excision with adjuvant

radiation therapy

d. Wide local excision with axillary

lymph node dissection and radiation

therapy

e. Simple mastectomy (without axillary

lymph node dissection)

f. Modified radical mastectomy (simple

mastectomy with in-continuity

axillary lymph node dissection)

g. Radical mastectomy

h. Bilateral prophylactic simple mastectomies

286. A 49-year-old woman undergoes

biopsy of a 1.0-cm breast

mass. Pathology shows extensive

comedo ductal carcinoma in situ.

(SELECT 2 CHOICES)

287. A 42-year-old woman with a

familial breast cancer (mother, four

sisters, and additional relatives)

undergoes her fifth breast biopsy

for a palpable mass. Pathology

shows ductal hyperplasia with

severe atypia. (SELECT 2

CHOICES)

288. A 51-year-old (premenopausal)

woman undergoes

needle localization biopsy for

microcalcifications. Pathology

reveals sclerosing adenosis with

microcalcifications and extensive

lobular carcinoma in situ.

(SELECT 1 CHOICE)

289. A 35-year-old woman presents

with a palpable 1.5-cm tumor

in the upper outer quadrant of her

left breast. Biopsy reveals invasive

ductal carcinoma with 10% intraductal

carcinoma. (SELECT 2

CHOICES)

290. A neglected 82-year-old

woman presents with a locally

advanced breast cancer that is

invading the pectoralis major muscle

over a broad base. She is otherwise

in good health. (SELECT 1

CHOICE)

164 Surgery

ENDOCRINE PROBLEMS

AND BREAST

Answers

241. The answer is d. (Greenfield, 2/e, pp 204-205.) Failure to recognize

adrenal cortical insufficiency, particularly in the postoperative patient, may

be a fatal error. This error is especially regrettable because therapy (exogenous

steroids) is effective and easy to administer. Adrenal insufficiency may

occur in a host of settings including tuberculosis (formerly the most common

cause), autoimmune states, severe infections (classically, meningococcal

septicemia), pituitary insufficiency, after burns, during anticoagulant

therapy, and-most commonly today-after interruption of chronically

administered exogenous steroids. Although the adrenal gland is an occasional

site for distant metastases, such as from lung or breast, it is rare for

there to be enough destruction of the glands to produce clinical adrenal

insufficiency. Chronic adrenal insufficiency (classic Addison's disease)

should be recognizable preoperatively by the constellation of skin pigmentation,

weakness, weight loss, hypotension, nausea, vomiting, abdominal

pain, hypoglycemia, hyponatremia, and hyperkalemia. Death may occur

within hours of surgery if a patient with Addison's disease is operated on

without cognizance of adrenal insufficiency and pretreatment with exogenous

steroids. Patients who have adrenal insufficiency as a result of interruption

of chronically administered exogenous steroids may not develop the

classic electrolyte abnormalities until the preterminal period. Adrenal insufficiency

may also develop insidiously in the postoperative period, progressing

over a course of several days. This insidious course is seen when adrenal

injury occurs in the perioperative period, as would be the case with adrenal

damage from hemorrhage into the gland in a patient receiving postoperative

anticoagulant therapy. Measurement of blood corticosteroid levels, urinary

corticosteroid secretion, urinary sodium levels, and the response to exogenous

steroids is helpful in establishing the diagnosis of adrenal insufficiency.

242. The answer is a. (Schwartz, 7/e, pp 1672, 1680.) The thyroid scan

illustrated in the question shows a single focus of increased isotope uptake,

165

often referred to as a "hot" nodule; the remainder of the thyroid gland has

not taken up radioactive iodine. Hyperfunctioning adenomas become

independent of thyroid stimulating hormone (TSH) control and secrete

thyroid hormone autonomously, which results in clinical hyperthyroidism.

The elevated thyroid hormone levels ultimately diminish TSH levels

severely and thus depress function of the remaining normal thyroid gland.

An isolated focus of increased uptake on a thyroid scan is virtually diagnostic

of a hyperfunctioning adenoma. Carcinomas usually display diminished

uptake and are called "cold" nodules. Graves' disease would probably

manifest as a diffusely hyperactive gland without nodularity. Multinodular

goiter would display many nodules with varying activity.

243. The answer is c. (Schwartz, 7/e, pp 601-602, 1717.) The thyroid

gland originates embryologically from the foramen cecum at the base of the

tongue. Normally, the thyroglossal duct becomes obliterated and resorbed,

but portions may remain patent and become filled with serous fluid, which

produces a midline cervical mass. Observe that in the scan of the patient

described in the question, the mass is central and appears not to be part of

the gland itself.

244. The answer is b. (Schwartz, 7/e, pp 543-546.) Breast biopsies have

traditionally been performed to obtain histology for clinically suspicious

palpable masses. In more recent years the advent of screening mammography

has led to the discovery of nonpalpable but radiographically suspicious

breast lesions that have a strong correlation with breast cancer. These

nonpalpable, mammographically detected lesions are (1) breast calcifications

that are (a) smaller than 2 mm, (b) punctate, microlinear, or branching,

and (c) clustered along ducts or concentrated in clusters greater than

five calcifications per square centimeter; (2) stellate-shaped lesions; (3)

masses with ill-defined borders or nodular contours; (4) solitary dominant

masses that are significantly larger than any other mass in either breast; and

(5) areas of increased noneffacing tissue density or distorted breast architecture.

A parenchymal density that effaces with compression represents

normal glandular tissue. Saucer-shaped microcalcifications are seen in

patients with microscopic cystic disease, a benign condition. Multiple

round well-circumscribed densities are usually cysts, whose nature may be

confirmed with breast sonography.

166 Surgery

245. The answer is d. (Schwartz, 7/e, pp 586-588.) The likelihood of

response of a breast cancer to hormonal therapy is dependent on the presence

of hormone receptors in the cytoplasm of the breast cancer cells.

Receptors for corticosteroids, progesterone, prolactin, and estrogen have

been identified. Eighty percent of patients with tumors that exhibit receptors

to both estrogen and progesterone respond favorably to hormonal

manipulation. Estrogen receptor activity has no predictive value in diagnosing

ovarian cancer or metastatic disease, forecasting the development of

osteoporosis, or determining the likelihood of a beneficial response to

chemotherapy.

246. The answer is b. (Schwartz, 7/e, pp 1620-1628.) Prolactin-secreting

tumors in the pituitary gland (previously called chromophobe adenomas)

may grow to large size and cause bitemporal hemianopia because of proximity

to the optic chiasm. They are typically associated with amenorrhea

and galactorrhea (the "A/G syndrome") in women. In both sexes lack of

libido and impotence or infertility may be noted. Sexual vigor is usually

restored after removal of the adenomas. These tumors are not life threatening;

if their physical size is not an issue or the relative sexual dysfunction is

not a problem, benign neglect is sometimes recommended.

247. The answer is c. (Norton, Ann Surg 215:297-299, 1992. Potts, Ann

Intern Med 114:593-597, 1991.) Primary hyperparathyroidism is a common

disease, with over 100,000 new cases diagnosed each year in the United

States, usually in women. Essential to the diagnosis of hyperparathyroidism

is the finding of hypercalcemia. Though there are many causes of

hypercalcemia, hyperparathyroidism is by far the most prevalent. With rare

exceptions, operations for primary hyperparathyroidism should not be

performed unless the patient is hypercalcemic. Parathyroid hormone

(PTH) is not invariably elevated, but it should be elevated relative to the

serum calcium level. Ordinarily, high serum calcium levels suppress

parathyroid secretion. Therefore, in the presence of hypercalcemia, normal

levels of PTH are "abnormal." Patients with primary hyperparathyroidism

have either normal or elevated urinary calcium. As the name suggests,

patients with familial hypocalciuric hypercalcemia (FHH) have hypercalcemia.

They also usually have elevated PTH, but surgery is not indicated in

this relatively rare setting of hypercalcemia.

Endocrine Problems and Breast Answers 167

248. The answer is b. (Greenfield, 2/e, pp 751-752, 869-870.) Somatostatin

is produced by D cells in the pancreatic islets and in a variety of other

tissue sites in the central nervous system, gut, and elsewhere. It is a potent

inhibitory regulator of intestinal hormones and motility. Because it was

originally found in the hypothalamus, somatostatin earned its name

because it was believed to be a major inhibitor of secretion of growth hormone.

It has now been shown to inhibit the secretion of most GI hormones,

particularly insulin and glucagon, as well as gastrin, secretin, VIP,

PP, gastric acid, pepsin, pancreatic enzymes, thyroid-stimulating hormone,

renin, and calcitonin. It also inhibits intestinal, biliary, and gastric motility,

and is occasionally of value in controlling bowel fistulas by sharply reducing

the amount of drainage. It has no known effect on adrenocortical cells.

249. The answer is e. (Greenfield, 2/e, pp 1344-1345.) Primary adrenal

pathology causes 10-20% of all cases of Cushing syndrome. A hyperfunctioning

adrenal adenoma can usually be lateralized by preoperative radiologic

studies, eliminating the need to explore both adrenal glands. In

10-15% of cases, adenomas are bilateral. The favored surgical approach

today is via transabdominal laparoscopy or by a posterior unilateral flank

route. The anterior transperitoneal approach should be reserved for complicated

cases such as large or obviously malignant lesions. After tumor

excision, corticosteroid therapy to correct postoperative hypoadrenalism is

necessary.

250. The answer is c. (Greenfield, 2/e, p 1373.) Most clinicians would

recommend aspiration and cytologic examination of the cyst fluid in this

situation. Cysts are common lesions in the breasts of women in their thirties

and forties; malignancies are relatively rare. All such lesions justify

attention, however, and physicians must not underestimate the fear associated

with the discovery of a mass in the breast, even in low-risk situations.

If the lesion does not completely disappear after aspiration, excision is

advised. In young women the breast parenchyma is dense, which limits the

diagnostic value of mammography. The American Cancer Society (ACS)

does not suggest a baseline mammographic examination until age 35

unless a suspicious lesion exists.

251. The answer is e. (Greenfield, 2/e, pp 1301-1303.) Radiation-induced

thyroid cancer was first recognized in 1950 by Duffy and Fitzgerald. It usu-

168 Surgery

ally follows low-dose external radiation. Most cancers occur after exposure

to 1500 rads or less to the neck, but an increase in thyroid cancer has been

noted after as little as 6 rads. Salivary gland tumors and possibly parathyroid

adenomas are also associated with radiation. The latent period for

these tumors is 30 years or longer. Of all patients who have low-dose radiation,

about 9% have been found to have thyroid cancer, usually of the

papillary type. Treatment consists of a near-total thyroidectomy because

there is a high incidence of bilaterality and because there is a greater incidence

of complications if a second operation is necessary.

252. The answer is d. (Greenfield, 2/e, pp 1301-1303.) Papillary carcinoma

of the thyroid frequently metastasizes to cervical lymph nodes, but

distant metastasis is uncommon. The nonaggressive nature of this tumor

locally and the infrequency of distant metastases combine to produce an

80-95% 5-year survival rate. A contributing factor to the success of thyroid

surgery for papillary carcinoma is the easy accessibility of cervical nodes for

examination and dissection. Slow growth and a predilection for local

extension are characteristics of this tumor that contribute to a high survival

rate in affected persons. This is true even of patients who have limited

surgery, which has led to considerable controversy regarding the extent of

the indicated surgical procedure.

253. The answer is c. (Greenfield, 2/e, pp 1372-1374.) Fibrocystic disease

(chronic cystic mastitis) is a common disorder of the adult female

breast. It is rare after cessation of ovarian function, either natural or

induced. Its association with estrogens is inferential. In postmenopausal

women it only occurs when replacement estrogen therapy is in use. Its

main clinical significance relates to the need to differentiate irregular breast

tissue from cancer. Patients afflicted with this disorder are often frustrated

by the repeated biopsies that may be recommended.

254. The answer is d. (Schwartz, 7/e, pp 552-553.) Fibroadenomas occur

infrequently before puberty but are the most common breast tumors

between puberty and the early thirties. They usually are well demarcated

and firm. Although most fibroadenomas are no larger than 3 cm in diameter,

giant or juvenile fibroadenomas frequently are very large. The bigger

fibroadenomas (greater than 5 cm) occur predominantly in adolescent

black girls. The average age at onset of juvenile mammary hypertrophy is

Endocrine Problems and Breast Answers 169

16 years. This disorder involves a diffuse change in the entire breast and

does not usually manifest clinically as a discrete mass; it may be unilateral

or bilateral and can cause an enormous and incapacitating increase in

breast size. Regression may be spontaneous and sometimes coincides with

puberty or pregnancy. Cystosarcoma phylloides may also cause a large

lesion. Together with intraductal carcinoma, it characteristically occurs in

older women. Lymphomas are less firm than fibroadenomas and do not

have a whorl-like pattern. They display a characteristic fish-flesh texture.

255. The answer is a. (Gajraj, Br J Surg 80:422-426, 1993.) With the

increasing use of CT and MRI scans for other purposes, small "incidentalomas"

of the adrenal gland are becoming a frequent finding. In the absence

of any clinical signs or symptoms of endocrine dysfunction, most experts

now recommend observation and a search for evidence of endocrine dysfunction

for lesions less than 5 cm in diameter. Lesions below that size are

common and are usually asymptomatic, nonfunctional adenomas or

adrenal cysts. Functional neoplasms secrete an excess of hormones, which

produces clinical signs and symptoms. All functional tumors and solid

tumors greater than 5.0 cm in diameter should be removed. Cystic masses

greater than 5 cm may be aspirated with a fine needle. Clear fluid suggests

a benign lesion; if the fluid is bloody or aspiration produces solid tissue,

then the lesion should be resected.

Cystic tumors ranging from 3.5 to 5.0 cm may also be aspirated. If

bloody fluid is obtained or if the lesion is solid, then resection should be

considered in a patient who is otherwise a healthy surgical candidate. Both

solid and cystic masses less than 3.5 cm may be followed and can be considered

benign if they do not increase in size or become functional.

256. The answer is a. (Schwartz, 7/e, pp 1679-1707.) The patient

described is exhibiting classic signs and symptoms of hyperparathyroidism.

In addition, if a history is obtainable, frequently the patient will

relate a history of renal calculi and bone pain-the syndrome characterized

as "groans, stones, and bones." The acute management of the hypercalcemic

state includes vigorous hydration to restore intravascular volume,

which is invariably diminished. This will establish renal perfusion and thus

promote urinary calcium excretion. Thiazide diuretics are contraindicated

because they frequently cause patients to become hypercalcemic. Instead,

diuresis should be promoted with the use of "loop" diuretics such as

170 Surgery

furosemide (Lasix). The use of intravenous phosphorus infusion is no

longer recommended because precipitation in the lungs, heart, or kidney

can lead to serious morbidity. Mithramycin is an antineoplastic agent that

in low doses inhibits bone resorption and thus diminishes serum calcium

levels; it is used only when other maneuvers fail to decrease the calcium

level. Calcitonin is useful at times. Bisphosphonates are newer agents particularly

useful for lowering calcium levels in resistant cases, such as those

associated with humoral malignancy. Finally, "emergency" neck exploration

is seldom warranted. In unprepared patients, the morbidity is unacceptably

high.

257. The answer is d. (Schwartz, 7/e, pp 64, 1698.) The mechanism of

hypercalcemia of malignancy is thought to be due to either elaboration of

a "PTH-like" humoral factor or, many times, direct bone destruction by

metastatic disease. Breast, prostatic, pulmonary, and hematologic malignancy

all may give rise to hypercalcemia. Serum and urine electrophoresis

may identify a malignancy that causes bone destruction, such as

multiple myeloma. Sarcoidosis may produce hypercalcemia, but the presence

of the normal chest x-ray essentially rules out this possibility. Thus,

a Kveim test is not indicated. An abdominal angiogram would not be

expected to identify a likely cause of hypercalcemia. Serum gastrin is not

implicated in the differential diagnosis of hypercalcemia. A neck exploration

would not be indicated unless a parathyroid adenoma or carcinoma

was suspected.

258. The answer is d. (Schwartz, 7/e, p 552.) Injury to breast tissue may

cause necrosis of mammary adipose tissue and lead to the formation of a

tender, localized, firm mass. A history of trauma is often elicited from

affected patients, but less apparent factors, such as prolonged pressure,

may also produce fat necrosis. Half the patients in whom the diagnosis is

made do not recall a history of trauma. The pathophysiology of this lesion

seems to involve early development of liquefaction of mammary fat with

the formation of a cystic mass. Through a process of fibrosis, this lesion

evolves into a firm, sometimes calcified lump that may be difficult to distinguish

from carcinoma. There is, however, no relation between fat necrosis

and the subsequent development of breast cancer. Excisional biopsy is

usually required for definitive diagnosis; if the diagnosis of fat necrosis is

confirmed, simple excision removes and terminates the process.

Endocrine Problems and Breast Answers 171

259-260. The answers are 259-c, 260-c. (Schwartz, 7/e, pp

1642-1645.) The constellation of symptoms in this patient is typical of a

functional adrenocortical tumor. Masculinization in females is also a common

finding. Elevated urine 17-ketosteroids will be found in this patient.

Any adrenocortical tumor larger than 6 cm should be considered a carcinoma

rather than an adenoma. Treatment should include resection, not

embolization, of as much tumor as possible. This would include invaded

adjacent organs such as the kidney or the tail of the pancreas. Symptoms

related to hormone production can be minimized by complete resection

despite the inability to cure advanced disease. The most effective adjuvant

therapy is mitotane, which is toxic for functional adrenocortical cells.

When mitotane is used, therefore, glucocorticoids must be administered.

Ketoconazole (not metronidazole) has been found to inhibit the production

of various steroid hormones and may be useful in the treatment of

hormone-related symptoms. The overall 5-year survival of patients with

adrenocortical carcinoma treated with resection and mitotane is 20%.

Phentolamine and phenoxybenzamine are α-adrenergic blockers that are

sometimes useful in the preoperative management of pheochromocytomas.

261. The answer is e. (Barnavon, Surg Gynecol Obstet 171:347-352, 1990.)

Approximately 2% of American women who develop carcinoma of the breast

are pregnant at the time of diagnosis. The therapeutic approach to these

patients has changed considerably in recent years. Though changes in the

breast that occur during pregnancy often lead to a delay in diagnosis of breast

carcinoma, there is no convincing evidence that breast carcinoma in pregnant

women behaves differently or is histologically different from that in

nonpregnant women. Furthermore, when patients are matched for age and

stage of disease, no significant differences in survival rates are found. The

majority of breast cancers in these patients, as with most premenopausal

patients, are estrogen-receptor negative and not hormonally sensitive. Therefore,

elective termination of pregnancy is generally no longer indicated to

decrease estrogen stimulation of the tumor. Since radiation exposure endangers

the fetus and there is no evidence that general anesthesia and nonabdominal

surgery increase premature labor, modified radical mastectomy is

recommended for stage I or II carcinoma (tumor less than 4 cm in diameter).

Patients in later stages of pregnancy, however, can start radiation therapy

shortly after delivery, and some may be candidates for breast-conserving

surgery and adjuvant radiotherapy. Chemotherapy does not appear to

172 Surgery

increase the risk of congenital malformation when given in the second or

third trimester of pregnancy. Patients who require adjuvant chemotherapy

during the first trimester may opt for a therapeutic abortion, however, since

there is a slightly increased risk of fetal malformation in that circumstance.

262. The answer is b. (Harris, pp 870-876.) Paget's disease of the breast

is unrelated to Paget's bone disease. It represents a small percentage (1-3%)

of all breast cancers and is thought to originate in the retroareolar lactiferous

ducts. It progresses toward the nipple-areola complex in most patients,

where it causes the typical clinical finding of nipple eczema and erosion.

Up to 20% of patients with Paget's disease have an associated breast mass,

and these patients are more likely to have involvement of axillary nodes.

Nipple-areolar disease alone usually represents in situ cancer; these

patients have a 10-year survival rate of over 80%. In contrast, if Paget's disease

presents with a mass, the mass is likely to be an infiltrating ductal carcinoma.

The generally recommended surgical procedure for Paget's disease

is currently a modified radical mastectomy. The validity of breast-saving

surgery and adjuvant radiation therapy for patients without an associated

mass is under investigation.

263. The answer is d. (Schwartz, 7/e, pp 1190-1196.) The syndrome of a

gastrin-secreting non-β-cell pancreatic tumor is a rare entity first described

by Zollinger and Ellison. They originally described a triad of (1) fulminant,

complicated peptic ulceration; (2) extreme gastric hypersecretion; and (3) a

non-β-cell tumor of pancreatic islets. Over 50% of the tumors are malignant,

and 40% have metastases at the time of surgery. Until recently, total

gastrectomy was the primary operation for this tumor; however, it is now

believed that operative exploration of the patient with resection of the

tumor should be done if possible. H2 receptor antagonists have also proved

very promising in the management of these patients. Patients with Zollinger-

Ellison tumors have very high basal gastric acid (greater than 35 meq/h) and

serum gastrin levels (usually greater than 200 pg/mL). A protein meal or histamine

usually does not increase acid and gastrin levels as it would in conventional

duodenal ulcer patients. A paradoxical rise in serum gastrin after

intravenous secretin is diagnostic of Zollinger-Ellison syndrome.

264. The answer is d. (Schwartz, 7/e, pp 1692-1693.) The incidence of

complications with thyroidectomy or parathyroidectomy is relatively low in

Endocrine Problems and Breast Answers 173

most series. Thyroid storm, a manifestation of severe thyrotoxicosis, is

avoided by prophylactic treatment with propylthiouracil or methimazole

prior to surgery. The remaining complications listed are complications of

technique. The likelihood of serious complications increases with the extent

of resection ("total thyroidectomy" versus "subtotal thyroidectomy") and

with the number of neck explorations (initial exploration versus reexploration).

Injury to the recurrent laryngeal nerve can compromise the airway,

as can hemorrhage into the wound. Superior laryngeal nerve injury causes

annoying voice "fatigue," but is rarely of significant consequence. Hypocalcemia

is usually transient, but can at times necessitate permanent calcium

supplementation. Perforation of hollow neck structures very seldom occurs,

and, unless it is massive or not appreciated, usually causes no morbidity.

265-266. The answers are 265-d, 266-e. (Schwartz, 7/e, pp

1697-1707.) This patient's presentation and films are consistent with primary

hyperparathyroidism. The elevated parathormone level (PTH) confirms

the diagnosis. Her chest film demonstrates marked osteopenia and

the hand films are classic for this disease with severe demineralization and

periosteal bone resorption most prominent in the middle phalanges. The

films show no evidence of malignant lesions or mediastinal adenopathy

consistent with sarcoidosis, and an elevated PTH level is not found in

Paget's disease or vitamin D intoxication.

Treatment for primary hyperparathyroidism in this setting is resection

of the diseased parathyroid glands after initial correction of the severe

hypercalcemia. A neck exploration would yield a single parathyroid adenoma

in about 85% of cases. Two adenomata are found less often (approximately

5%) and hyperplasia of all four glands occurs in about 10-15% of

patients. If hyperplasia is found, treatment includes resection of three and

one-half glands. The remnant of the fourth gland can be identified with a

metal clip in case reexploration becomes necessary. Alternatively, all four

glands can be removed with autotransplantation of a small piece of parathyroid

tissue into the forearm or sternocleidomastoid muscle. Subsequent

hyperfunction, should it develop, can then be treated by removal of this tissue.

A patient with osteopenia this severe will need calcium supplementation

postoperatively. Vitamin D supplementation may also be necessary if

hypocalcemia develops and persists despite treatment with oral calcium.

267. The answer is a. (Schwartz, 7/e, pp 1678-1689.) The thyroid scan of

the patient discussed in the question shows a discrete area of decreased

174 Surgery

radioactive iodine uptake with the remainder of the gland accepting iodine

normally. This means the tissue that composes the nodule is not endocrinologically

active for thyroid hormone. The two major mass lesions of the

thyroid that can produce this pattern are a nonfunctioning follicular adenoma

and a carcinoma. Carcinomas seldom produce thyroid hormone.

Adenomas may be very active (toxic) and suppress the remaining gland.

Most thyroid adenomas, however, are not hormone producing and appear

as "cold" nodules on a thyroid scan. Graves' disease produces a diffusely

hyperactive gland without nodularity. de Quervain's thyroiditis presents as

a painful, swollen thyroid gland rather than as a discrete nodule. A large

parathyroid adenoma could conceivably displace the thyroid gland and

produce a pattern similar to the one shown, but it would be unusual. A

localized infectious process also could produce such a pattern. The essential

point is that a "cold" thyroid nodule may represent a carcinoma, and

needle biopsy or surgical excision is indicated to rule out this possibility.

268. The answer is a. (Schwartz, 7/e, pp 552-553.) Cystosarcoma phylloides

is a tumor most often seen in younger women. It can grow to enormous

size and at times ulcerate through the skin. Still, it is a lesion with

low propensity toward metastasis. Local recurrence is common, especially

if the initial resection was inadequate. Simple reexcision with adequate

margins is curative. Very large lesions may necessitate simple mastectomy

to achieve clear margins. Axillary lymphadenectomy, however, is seldom

indicated without biopsy-positive demonstration of tumor in the nodes.

The low incidence of metastatic disease suggests that adjunctive therapy is

indicated only for known metastatic disease, even when the tumors are

quite large and ulcerated.

269. The answer is e. (Schwartz, 7/e, pp 1681-1684.) This patient has cytologic

evidence of a papillary lesion, possibly papillary carcinoma. Papillary

carcinoma is a relatively nonaggressive lesion with long-term survival (>20

years) of more than 90%. The lesion is frequently multicentric, which argues

for more complete resection. Metastases, when they occur, are usually responsive

to surgical resection or radioablation therapy. Removal of the involved

lobe, and possibly the entire thyroid gland, is appropriate. Central and lateral

lymph node dissection is performed for clinically suspect lymph nodes. Papillary

carcinoma is frequently multifocal. Bilateral disease mandates total thyroidectomy.

The use of radioactive 131I, however, is contraindicated in

pregnancy and should be used with caution in women of childbearing age.

Endocrine Problems and Breast Answers 175

270. The answer is c. (Schwartz, 7/e, pp 1685-1686.) Hürthle-cell cancer

is a type of follicular cancer, but it tends to recur more often than other

types. Follicular cancer spreads hematogenously to distant sites. This is

unlike papillary cancer, which metastasizes via the lymphatics. Amyloid

deposits in the stroma of a thyroid tumor are diagnostic of medullary carcinoma.

The treatment of choice is a near-total thyroidectomy to facilitate

later body scanning for metastases and treatment with 131I.

271. The answer is e. (Schwartz, 7/e, pp 1681-1689.) Thyroid nodules

are somewhat less common in men and should always suggest malignancy.

The history of irradiation to the chest and the findings on biopsy mandate

resection of the lesion in this patient, since prior exposure to radiation,

even at low dosage, is a strong risk factor for the subsequent development

of thyroid cancer. The optimum management of thyroid carcinoma

remains controversial. Thyroid lobectomy, subtotal thyroidectomy, and

total thyroidectomy are all acceptable techniques for treatment. Removal of

the gland permits more accurate histologic diagnosis, particularly with

regard to the relatively radioresistant Hürthle-cell follicular variant.

Removal of the gland also makes subsequent treatment of metastases with

radioactive iodine more effective. Suppression with thyroid hormone (Synthroid)

in the setting of abnormal cytology is not recommended.

272. The answer is a. (Harris, pp 106-110.) Nipple discharge from the

breast may be classified as pathologic, physiologic, or galactorrhea. Galactorrhea

may be due to hormonal imbalance (hyperprolactinemia,

hypothyroidism), drugs (oral contraceptives, phenothiazines, antihypertensives,

tranquilizers), or trauma to the chest. Physiologic nipple discharge

is intermittent, nonlactational (usually serous), and due to stimulation

of the nipple or to drugs (estrogens, tranquilizers). Both galactorrhea

and physiologic discharge are frequently bilateral and arise from multiple

ducts. Pathologic nipple discharge may be caused by benign lesions

of the breast (duct ectasia, papilloma, fibrocystic disease) or by cancer. It

may be bloody, serous, or gray-green. It is spontaneous and unilateral and

can often be localized to a single nipple duct. When pathologic discharge

is diagnosed, an effort should be made to identify the source. If an associated

mass is present, it should be biopsied. If no mass is found, a terminal

duct excision of the involved duct(s) should be performed. Only 10 percent

of patients with pathologic nipple discharge are found to have breast

cancer.

176 Surgery

273. The answer is c. (Schwartz, 7/e, pp 1622-1623, 1635-1639.) Cushing's

disease is caused by hypersecretion of ACTH by the pituitary gland.

This hypersecretion, in turn, is caused by either a pituitary adenoma (90%

of cases) or diffuse pituitary corticotrope hyperplasia (10% of cases) due to

hypersecretion of CRH (corticotropin-releasing hormone) by the hypothalamus.

A high cure rate is achieved with surgery, occasionally followed by

adjuvant radiotherapy for large pituitary adenomas. Cushing syndrome

refers to the clinical manifestations of glucocorticoid excess due to any

cause (Cushing's disease, administration of exogenous glucocorticoids,

adrenocortical hyperplasia, adrenal adenoma, adrenal carcinoma, ectopic

ACTH-secreting tumors) and includes truncal obesity, hypertension, hirsutism,

moon facies, proximal muscle wasting, ecchymoses, skin striae,

osteoporosis, diabetes mellitus, amenorrhea, growth retardation, and

immunosuppression. The most common cause of Cushing syndrome is

iatrogenic, via administration of synthetic corticosteroids.

274. The answer is d. (Schwartz, 7/e, pp 1493-1494, 1686-1688.) Insulinsecreting

β-cell tumors of the pancreas produce paroxysmal nervous system

manifestations that may be a consequence of hypoglycemia, although the

blood glucose level may bear little relation to the severity of the symptoms,

even in the same patient from episode to episode. Most insulinomas are single

discrete tumors. Patients with insulinoma in the setting of the MEN 1

syndrome (synchronous islet cell tumors of the pancreas, pituitary hyperplasia

or adenomas, and parathyroid chief cell hyperplasia), however, are

more likely to have multiple tumors throughout the pancreas. If a careful

examination of the pancreas reveals one or more specific adenomas, these

can be locally excised. Excision of these tumors may be difficult in MEN 1,

when the tumors are small and multiple (10-15% of cases). The finding of

an elevated serum calcium level would raise the suspicion of MEN 1 and

parathyroid hyperplasia. Insulinomas are not associated with MEN 2, which

comprises coexistent medullary thyroid cancer, parathyroid hyperplasia,

and pheochromocytoma. About one in seven of these tumors is malignant.

Streptozotocin, a potent antibiotic that selectively destroys islet cells, can be

useful in controlling symptoms from unresectable malignant tumors of the

islet cells but probably has little to offer in the definitive management of the

typical benign islet cell insulinoma.

275. The answer is a. (Harris, pp 159-167.) Breast cancer is rarely seen

before the age of 20, but thereafter its incidence increases inexorably. While

Endocrine Problems and Breast Answers 177

the prevalence of breast cancer (the raw number of patients alive with disease)

is greatest among perimenopausal women, the incidence of breast cancer

(the number of new cases per 100,000 population) rises so sharply that it

is twice as common among women between 80 and 85 years of age as among

those 60 to 65. In addition, the age-adjusted incidence has increased steadily

since the mid-1940s. No data is presently available consistently linking the

incidence of breast cancer to dietary factors. A possible linkage between

breast cancer and alcohol consumption at an early age is being studied.

276-280. The answers are 276-c, 277-b, 278-b, 279-e, 280-d.

(Schwartz, 7/e, p 321.) The American Joint Committee on Cancer has

defined a four-tiered staging system for breast cancer based on the clinical

criteria of tumor size, involvement of lymph nodes, and metastatic disease.

In one version of this system, a separate category is reserved for inflammatory

breast cancer. While the grouping of breast cancers into stages provides

a useful shorthand for expressing a patient's survival probability, it is

noteworthy that considerable heterogeneity exists both with respect to

tumor size and nodal characteristics among tumors that are classified

within a given stage.

The TNM stage of breast cancer is assigned by measuring the greatest

diameter of the tumor ("T"), assessing the axillary and clavicular lymph

nodes for enlargement and fixation ("N"), and judging whether metastatic

disease is present ("M"). In general, the worst of the three TNM parameters

will determine the stage assignment.

Tumors that are not palpable are classified T0; tumors 2 cm or less, T1;

tumors greater than 2 but not more than 5 cm, T2; tumors greater than 5

cm, T3; and tumors with extension into the chest wall or skin, T4.

Clinically negative lymph nodes are classified N0; positive, movable

ipsilateral axillary nodes, N1; fixed ipsilateral axillary nodes, N2; and clavicular

nodes, N3.

Absence of evidence of metastatic disease is classified M0; distant

metastatic disease, M1.

The patient in question 276 has a T0, N2, M0 lesion. This is stage III

(fixed or matted nodes are a poor prognostic sign).

The patient in question 277 has a T2, N1, M0 lesion. This is stage II.

The patient in question 278 has a T2, N0, M0 lesion. Though smaller

than the tumor in question 277 and without clinically involved nodes, this

tumor is also stage II.

178 Surgery

The patient in question 279 has findings compatible with inflammatory

breast cancer. A biopsy of the involved skin and a mammogram would

confirm the diagnosis.

The patient in question 280 has a T1, N0, M1 lesion. This is stage IV

(stage IV is any T, any N, M1).

281-285. The answers are 281-d, 282-a, 283-b, 284-e, 285-c.

(Schwartz, 7/e, pp 1244-1246.) Carcinoid tumors are most commonly found

in the appendix and small bowel, where they may be multiple. They have a

tendency to metastasize, which varies with the size of the tumor. Tumors

< 1 cm uncommonly metastasize. Tumors > 2.0 cm are more often found to

be metastatic. Metastasis to the liver and beyond may give rise to the carcinoid

syndrome. The tumors cause an intense desmoplastic reaction. Spread

into the serosal lymphatics does not imply metastatic disease; local resection

is potentially curative. When metastatic lesions are found in the liver, they

should be resected when technically feasible to limit the symptoms of the

carcinoid syndrome. When extensive hepatic metastases are found, the disease

is not curable. Resection of the appendix and cecum may be performed

to prevent an early intestinal obstruction by locally encroaching tumor.

286-290. The answers are 286-c, f; 287-a, h; 288-a; 289-d, e; 290-

g. (Schwartz, 7/e, pp 572-586.) Generally accepted treatment for stage I

breast cancer in premenopausal women includes lumpectomy (wide excision,

partial mastectomy, quadrantectomy) combined with axillary lymph

node dissection and adjuvant radiation therapy, and modified radical mastectomy.

Both approaches offer equivalent chances of cure; there is a higher

incidence of local recurrence with lumpectomy, axillary dissection, and

radiation, but this observation has not been found to affect the overall cure

rate in comparison with mastectomy.

Patients with familial breast cancer (multiple first-degree relatives and

penetrance of breast cancer through several familial generations) have

extremely high risks of developing breast cancer in the course of their lifetimes.

A subset of patients with familial breast cancer has been identified

by a specific gene mutation (BRCA1); however, the genetic basis of most

cases of familial breast cancer has yet to be elucidated. A patient with a history

of familial breast cancer and multiple biopsies showing atypia may reasonably

request bilateral prophylactic simple mastectomies. Alternatively,

she may continue with routine surveillance.

Endocrine Problems and Breast Answers 179

Lobular carcinoma in situ is a histologic marker that identifies patients

who are at increased risk for the development of breast cancer. It is not a

precancerous lesion in itself, and there is no benefit to widely excising it

because the risk of subsequent cancer is equal for both breasts. As the risk

for the future development of breast cancer is now estimated to be approximately

1% per year, prophylactic mastectomy is no longer recommended.

Proper management would consist of close surveillance for cancer by twice

yearly examinations and yearly mammography. Sclerosing adenosis is a

benign lesion.

Ductal carcinoma in situ is the precursor of invasive ductal carcinoma.

It is described in four histologic variants (papillary, cribriform, solid, and

comedo type), of which the comedo subtype shows the greatest tendency

to recur after wide excision alone. For years, ductal carcinoma in situ was

treated by simple mastectomy. In recent years, studies have shown equally

good results with wide excision alone (for small noncomedo lesions) or

wide excision plus radiation therapy. For a 1.0-cm comedocarcinoma

(which may extend microscopically wider still), most experts would favor

simple mastectomy or wide excision with radiation therapy.

There are few indications for radical mastectomy as it is both more

traumatic and disfiguring than any other method of local control of breast

cancer and offers no greater survival benefit. One indication for radical

mastectomy, however, is locally advanced breast cancer with wide invasion

of the pectoralis major in a patient who is physiologically able to tolerate

general anesthesia.

180 Surgery

GASTROINTESTINAL

TRACT, LIVER,AND

PANCREAS

Questions

DIRECTIONS: Each item below contains a question or incomplete

statement followed by suggested responses. Select the one best response to

each question.

181

291. Omeprazole has been added

to the H2 antagonists as a therapeutic

approach to the management of

acute gastric and duodenal ulcers.

It acts by

a. Blocking breakdown of mucosaldamaging

metabolites of NSAIDs

b. Providing a direct cytoprotective

effect

c. Buffering gastric acids

d. Inhibiting parietal cell hydrogenpotassium-

ATPase

e. Inhibiting gastrin release and parietal

cell acid production

292. Evidence that a splenectomy

might benefit a patient with

immune (idiopathic) thrombocytopenic

purpura (ITP) includes

a. A significant enlargement of the

spleen

b. A high reticulocyte count

c. Megakaryocytic elements in the

bone marrow

d. An increase in the platelet count on

cortisone therapy

e. Patient age of less than 5 years

Terms of Use

293. An 18-year-old woman presents with abdominal pain, fever, and

leukocytosis. With the presumptive diagnosis of appendicitis, a right lower

quadrant (McBurney) incision is made and the lesion pictured below is

delivered. The process is 50 cm proximal to the ileocecal valve. This lesion

182 Surgery

a. Can best be diagnosed by preoperative angiogram, which should be done

whenever the diagnosis is suspected

b. Should routinely be removed when incidentally discovered during celiotomy

c. Is embryologically derived from a persistent vitelline duct (omphalomesenteric

duct)

d. Often contains ectopic adrenal tissue

e. Is frequently associated with cutaneous flushing and episodic tachycardia

294. A 41-year-old man complains of regurgitation of saliva and of

ingested but undigested food. An esophagram reveals a "bird's beak" deformity.

Which of the following statements is true about this condition?

a. Chest pain is common in the advanced stages of this disease

b. More patients are improved by forceful dilation than by surgical intervention

c. Manometry can be expected to show high resting pressures of the lower

esophageal sphincter

d. Surgical treatment primarily consists of resection of the distal esophagus with

reanastomosis to the stomach above the diaphragm

e. Patients with this disease are at no increased risk for the development of carcinoma

295. Which of the following statements

concerning imperforate anus

is true?

a. Imperforate anus affects males

more frequently than females

b. In 90% of males, but only 50% of

females, the rectum ends below the

level of the levator ani complex

c. The rectum usually ends in a blind

pouch

d. The chance for eventual continence

is greater when the rectum has

descended to below the levator ani

muscles

e. Immediate definitive repair of the

anatomic defect is required to maximize

the chance of eventual continence

Items 296-297

A previously healthy 80-yearold

woman presents with early satiety

and abdominal fullness. The CT

scan shown below is obtained.

Gastrointestinal Tract, Liver, and Pancreas 183

296. The lesion is most likely a

a. Pancreatic pseudocyst

b. Pancreatic adenocarcinoma

c. Pancreatic cystadenocarcinoma

d. Retroperitoneal lymphoma

e. Pancreatic serous cystadenoma

297. Which of the following statements

about this lesion is true?

a. Clinical and laboratory findings

together establish a preoperative

diagnosis

b. Significant weight loss and back

pain are the typical presentation

c. The lesion may be multilocular or

calcified

d. It is unlikely to be cured by resection

if large

e. It is associated with a history of

pancreatitis

298. A patient with a history of

familial polyposis undergoes a

diagnostic polypectomy. Which of

the following types of polyps is

most likely to be found?

a. Villous adenoma

b. Hyperplastic polyp

c. Adenomatous polyp

d. Retention polyp

e. Pseudopolyp

299. What is the most common

serious complication of an end

colostomy?

a. Bleeding

b. Skin breakdown

c. Parastomal hernia

d. Colonic perforation during irrigation

e. Stomal prolapse

300. Which of the following statements

regarding pancreatic carcinoma

is true?

a. The majority of cases present with

jaundice alone

b. CT scan, angiography, and laparoscopy

have been unsuccessful in

predicting resectability

c. If a patient is jaundiced, the

resectability rate is less than 5%

d. 99% of patients with pancreatic

cancer have metastatic disease at

the time of diagnosis

e. The 5-year survival rate after a

Whipple procedure (pancreaticoduodenectomy)

performed for cure

is 30-40%

Items 301-302

A 45-year-old woman is

explored for a perforated duodenal

ulcer 6 h after onset of symptoms.

She has a history of chronic peptic

ulcer disease treated medically with

minimal symptoms.

301. The procedure of choice is

a. Simple closure with omental patch

b. Truncal vagotomy and pyloroplasty

c. Antrectomy and truncal vagotomy

d. Highly selective vagotomy

e. Hemigastrectomy

302. Six weeks after surgery, the

patient returns complaining of

postprandial weakness, sweating,

light-headedness, crampy abdominal

pain, and diarrhea. The best

management would be

a. Antispasmodic medications (e.g.,

Lomotil)

b. Dietary advice and counseling that

symptoms will probably abate

within 3 mo of surgery

c. Dietary advice and counseling that

symptoms will probably not abate

but are not dangerous

d. Workup for neuroendocrine tumor

(e.g., carcinoid)

e. Preparation for revision to Rouxen-

Y gastrojejunostomy

184 Surgery

Items 303-304

A 60-year-old male alcoholic is

admitted to the hospital with

hematemesis. His blood pressure is

100/60 mm Hg, the physical examination

reveals splenomegaly and

ascites, and the initial hematocrit is

25%. Nasogastric suction yields

300 mL of fresh blood.

303. A 55-year-old man complains

of chronic intermittent epigastric

pain, and gastroscopy

demonstrates a 2-cm ulcer of the

distal lesser curvature. Endoscopic

biopsy yields no malignant tissue.

After a 6-wk trial of H2 blockade

and antacid therapy, the ulcer is

unchanged. Proper therapy at this

a. Repeat trial of medical therapy

b. Local excision of the ulcer

c. Billroth I partial gastrectomy

d. Billroth I partial gastrectomy with

vagotomy

e. Vagotomy and pyloroplasty

304. After initial resuscitation, this

man should undergo

a. Esophageal balloon tamponade

b. Barium swallow

c. Selective angiography

d. Esophagogastroscopy

e. Exploratory celiotomy

305. A diagnosis of bleeding

esophageal varices is made in this

patient. Appropriate initial therapy

would be

a. Intravenous vasopressin

b. Endoscopic sclerotherapy

c. Emergency portacaval shunt

d. Emergency esophageal transection

e. Esophageal balloon tamponade

306. During an operation for carcinoma

of the hepatic flexure of the

colon, an unexpected discontinuous

3-cm metastasis is discovered

in the edge of the right lobe of the

liver. The surgeon should

a. Terminate the operation, screen the

patient for evidence of other metastases,

and plan further therapy after

the reevaluation

b. Perform a right hemicolectomy and

a right hepatic lobectomy

c. Perform a right hemicolectomy and

a wedge resection of the metastasis

d. Perform a cecostomy and schedule

reoperation after a course of systemic

chemotherapy

e. Perform local resection of the primary

colon cancer and plan radiation

therapy for the lesion on the

liver

Gastrointestinal Tract, Liver, and Pancreas 185

307. A 42-year-old man with no

history of use of nonsteroidal antiinflammatory

drugs (NSAIDs) presents

with recurrent gastritis.

Infection with Helicobacter pylori is

suspected. Which of the following

statements is true?

a. Morphologically, the bacteria is a

gram-positive, tennis-racket-shaped

organism

b. Diagnosis can be made by serologic

testing or urea breath tests

c. Diagnosis is most routinely

achieved via culturing endoscopic

scrapings

d. The most effective way to treat and

prevent recurrence of this patient's

gastritis is through the use of singledrug

therapy aimed at eradicating

H. pylori

e. The organism is easily eradicated

308. Which of the following hernias

follows the path of the spermatic

cord within the cremaster

muscle?

a. Femoral

b. Direct inguinal

c. Indirect inguinal

d. Spigelian

e. Interparietal

309. A spry octogenarian who has