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Flashcards in surgical infections Deck (158):
1

what are concentrated in the region of bacterial invasion

complement, fibrinogen, and opsonins

2

what are concentrated in the region of bacterial invasion

complement, fibrinogen, and opsonins

3

mc type of SSI

superficial and incisional- range from simple cellulitis of the wound to overt infection of the wound bed above the fascia

4

tx superficial and incisional SSI

oral abx (most are gram pos) for cellulitis and reopening of the wound for those w infx w incisional purulent drainage and involvement of deeper tissues

5

deep incisional SSI

extend into muscle and fascia; require opening and freq surgical debridement of necrotic tissue

6

wounds at what location are at high risk for fascial necrosis and dehiscence

abdomen

7

tx deep incisional SSI

abx and cont daily local wound care

8

more severe forms of deep incisional SSI

necrotizing fasciitis, systemic infx, sepsis

9

ex of infx of organ/intracavitary space

peritonitis, intra abdominal abscess and empyema

10

surgical skin prep

povidone-iodine solution or chlorhexidine containing solutions

11

what are 2 key preventive measures

adequate tissue perforation and oxygenation

12

minimum inhibitory concentration

refers to the lowest concentration necessary to visibly inhibit growth under typical conditions

13

to insure adequate serum and tissue levels, initial abx are given how long prior to incision

1hr

14

abx for cardiac or vascular

cefazolin (ancef), cefuroxime, or vanco

15

abx for hip/knee arthroplasty

cefazolin (ancef), cefuroxime, or vanco

16

abx colon

Cefotetan, cefoxitin, ampicillin/sulbactam or ertapenem

OR

Cefazolin or cefuroxime + metronidazole

If β-lactam allergy:

Clindamycin + aminoglycoside or quinolone or aztreonam

OR

Metronidazole with aminoglycoside or

Metronidazole + quinolone

17

abx hysterectomy

cefotetan, cefazolin, cefoxitin, cefuroxime or Ampicillin/sulbactam

If β-lactam allergy

Clindamycin + aminoglycoside or quinolone or aztreonam

OR

Metronidazole + aminoglycoside or

Metronidazole + quinolone

OR

Clindamycin monotherapy

18

how long is periop abx therapy cont for

19

6 key quality indicators related to the periop manag of surgical pts that related to surgical infx according to SCIP and CMS

1. Prophylactic antibiotic delivery within 60 minutes prior to incision

2. Prophylactic antibiotics consistent with approved guidelines

3. Cessation of prophylaxis within 24 hours following surgery

4. Appropriate hair removal (clipping)

5. Glucose control for cardiac surgery

6. Normothermia for colorectal surgery

20

all infx that occur after surgical procedures are considered

nosocomial (hospital acquired)

21

fever that occurs in postop setting can be an early indication of

dev infx

22

W's of postop fever

wind (1-2d), water (2-3d), wound (3-5d), walking (5-7d), W abscess (7-10d), wonder drugs (anytime)

23

usually early and first cause of temp elev postop

lung atelectasis

24

4 major components to prevent HAP/VAP

(1) elevation of the head of the bed to 30°, (2) daily sedation vacation and assessment for weaning, (3) stress ulcer prophylaxis, and (4) venous thromboembolism prevention

25

a quantitative bronchial aspirate of what of aspirate is dx of invasive infx for VAP

>10^5 organisms/mL

26

abx use for pts in the hospital 10days

10d or immunocomp are at greater risk and abx should cover MRSA and resistant gram negative rods

27

tx for VAP

frequent airway suction;specific abx tx for 8 days

28

greatest risk factor for dev a UTI

presence of an indwelling bladder catheter

29

dx UTI

bacterial cx >100,000

30

when a postop pt w signs of infx dev a pleural effusion, the composition of fluid should be determined by

thoracentesis

31

transudative effusion

due ot inc hydrostatic forces and has low protein content

32

exudative effusion

inc permeability and has high protein content

33

what helps to differentiate exudates

LDH, glucose, pH, cell count, and gram stain

34

results of exudative effusions due to inflammation

pH 3xserum level

35

tx symptomatic pts or lg volume effusions assoc w characteristics assoc w exudate on thoracentesis

adequate drainage of the pleural space must be accomplished; abx

36

dx of exudate on imaging

ct scan w loculated rim enhancing pleural collection

37

mc cause of intra abd infx in surgical pt

perf or leakage from a hollow viscus that leads to bacterial seeding of the peritoneal cavity

38

2 response to perf or leakage of abd cavity

abscess formation or generalized peritonitis

39

primary peritonitis

spontan bacterial peritonitis that occurs wout breach of GI tract or peritoneal cavity, usually mono microbial, and seen in chronic alcoholics

40

secondary peritonitis

polymicrobial and occurs as result of spillage of gut organisms from GI tract or contamination of indwelling catheters

41

tertiary peritonitis

critically ill pts and persists or recurs at least 48hrs after apparent adequate manage, polymicrobial, and reflects a failure of host defense rather than source control

42

tx for any postop patient that demonstrates signs of systemic sepsis

broad spectrum abx

43

dx postop sepsis

blood cx, CT w PO and IV contrast*

44

blanching erythema of cellulitis caused by

group a strep and responds to penicillin tx

45

cellulitis

break in skin barrier, strep, warm to touch, diffuse erythema, tenderness, tx systemic abx and local wound care

46

furuncle, carbuncle

bacterial growth within skin glands/crypts, staph, localized induration, erythema, tenderness, swelling w purulent discharge,tx i/d, abx

47

hldradenitis suppurativa

bacterial growth within apocrine sweat glands, staph, multiple localized subcut abscesses, drainage, commonly axilla and groin, tx i/d small lesions, abx, lg needs wide local excision and skin grafting

48

lymphangitis

infx within lymphatics, strep, diffuse swelling, erythema of distal extremity w areas of inflamed streaks along lymphatic channels, tx local wound care, abx, removal fb, elevation extremity

49

gangrene, nsti's

destruction of healthy tissue by virulent microbial enzymes, strep/staph/clostridium,Necrotic skin/fascia, swelling and Induration, foul smelling discharge, crepitus with subcutaneous emphysema, frequently with toxic systemic signs and symptoms of sepsis

Radical débridement/amputation of involved tissues, aggressive local wound care with frequent débridement as necessary, parenteral broad-spectrum antibiotics

50

4 types of necrotizing soft tissue infx (NSTI)

cellulitis, fasciitis, myositis, vasculitis

51

what does non blanching erythema indicate

subdermal thrombosis of the nutrient blood supply of the skin; tx surgical debridement, high dose penicillin and clinda

52

clostridial myonecrosis or clostridial cellulitis

fulminant life threatening infx characterized by tissue necrosis and rapidly adv crepitus (gas gangrene); debridement and high dose penicillin

53

restlessness, headache, masseter muscle stiffness, and muscular contractions in area of the wound

tetanus (lockjaw); clostridium tetoni

54

tx tetanus

debridement and cleansing of all wounds in which devitalized, contaminated tissue is present

55

tetanus prone

>6hr, crush, avulsion, extensive abrasion, burns, frostbite, contaminants (soil, saliva) present

56

nontetanus prone

57

tetanus prophylaxis

unknown or

58

cause of breast abscess

staph

59

who is at higher risk for breast abscess

postpartum women

60

tx breast abscess

i/d, abx, bx

61

infx within crypts of anorectal canal and present as tender mass in perianal area

perirectal abscess

62

if perirectal abscess involves an invasive infx and results in sub cut tissue necrosis what is tx

wide debridement for salvage; colostomy diversion to avoid further soilage to area and sequelae of fecal incontinence if sphincter is involved

63

paronychia

staph infx of proximal fingernail that erupts at sulcus of the nail border

64

tx paronychia

i/d, resection of portion of embedded nail, hot soaks

65

felons

deep infx of terminal phalanx pulp space; occur after distal phalanx penetrating injuries and are tx by drainage; removal of nail may be necessary

66

neglected infections of the fingers may result in

tenosynovitis; infx extends along tendon sheath

67

organisms of bites human and animals

eikenella corrodens for humans and pasteurella for dogs/cats

68

abx for biliary tract infx

cefazolin or cefoxitin

69

mc inflammatory and infectious process in biliary tract

acute cholecystitis

70

acute peritonitis

bacteria present within the normally sterile peritoneal cavity

71

ct finding of peritonitis

upright chest roentgenogram commonly shows pneumoperitoneum beneath a hemidiaphragm with acute GI perforation and small amounts of pneumoperitoneum

72

all pts w ulcer assoc perf should be assessed for presence of

helicobacter pylori

73

abx for appendix

aerobic (e coli) and anaerobic (bacteroides fragilis) coverage

74

cause and tx fungal infx

Candida; fluconazole, ketoconazole, miconazole, nystatin

75

3 mc viral illnesses of concern for injury (needle stick)

hep B*, hep C, HIV

76

A 32-year-old man is seen in the emergency department 45 minutes after a motor vehicle collision. His only injury is a long linear laceration beginning on the left temporal forehead at the hairline and extending posteriorly for 10 cm. The edges are still bleeding briskly and the EMTs described a large amount of blood at the scene. He did not lose consciousness. His last tetanus booster was 4 years ago. Which of the following is required for tetanus prophylaxis In this patient?

A. Tetanus immune globulin only

B. Nothing further at this time

C. Tetanus toxoid only

D. Tetanus immune globulin followed by a single tetanus toxoid booster

E. Tetanus immune globulin followed by three tetanus boosters

Answer: B

Wounds prone to the development of tetanus Include those with extensive contamination with soil, deep puncture wounds from metal objects, exposure Injury complicated with frostbite, and wounds >6 hours from time of Injury (Table 8-8.). Linear lacerations In general are not prone to tetanus. The extent of blood loss does not affect the need for tetanus booster administration. The patient last received tetanus toxoid

77

A 48-year-old man Is being evaluated In the emergency department with fevers, chills, and abdominal pain for the past 24 hours. He has a history of hepatitis C infection following a blood transfusion 14 years ago for a large scalp laceration and orthopedic injuries sustained In a motor vehicle collision. He has not been to a physician for 5 years. He does not smoke or drink alcohol. He takes no medications. His temperature is 39°C and vital signs are: blood pressure (BP) 90/50 mm Hg, pulse 110/minute, and respirations 26/minute. A CT scan shows a single stone in the gallbladder that does not appear to be obstructing. The bile ducts are normal caliber and the gallbladder wall Is not thickened. There Is a moderate amount of fluid, mild small bowel distention, and stranding around the sigmoid colon as well as a small amount of free Intraperitoneal gas around the liver. An aspirate of the peritoneal fluid shows leukocytes and mixed Gram positives and negatives on Gram stain. Laboratory values show a WBC of 19,000/mm3, total bilirubin 1.2 mg/dL, and alkaline phosphatase 40 U/L. In addition to fluid resuscitation and broad-spectrum antibiotics, what is the best step in management?

A. Laparoscopic cholecystectomy

B. Long-term antibiotics only

C. Laparotomy

D. Magnetic resonance cholangiopancreatography (MRCP)

E. Endoscopic retrograde cholangiopancreatography (ERCP)

Answer: C

This patient has secondary peritonitis. This usually involves perforation of a hollow vlscus and thus involves contamination of the peritoneal cavity with multiple organisms. Gram stain and culture of the peritoneal fluid usually shows a single organism In patients with primary peritonitis and this can be treated with antibiotics without surgical Intervention. In this scenario, the CT scan shows stranding around the sigmoid and fluid and evidence of free air suggestive of a diverticulitis with fecal peritonitis. Patients with underlying liver disease are prone to gallstones and are a common finding. There Is no evidence of common bile duct obstruction that warrants further investigation since the alkaline phosphatase is normal.

78

A 42-year-old woman Is seen In the infectious disease clinic because of a small laceration. She is a surgeon and was assisting a surgical resident with a colon resection when she was accidentally cut with a scalpel blade during the procedure. She has received all required Immunizations. Antibodies against which virus could be measured in order to assess the effectiveness of the only vaccine to prevent Infection potentially transmitted from the patient to the surgeon during the operative procedure?

A. Human immunodeficiency virus

B. Hepatitis C

C. Hepatitis B

D. Cytomegalovirus

E. Tuberculosis

Answer: C

HIV, hepatitis B, hepatitis C, and cytomegalovirus are transmitted by body fluids and blood; therefore, they pose an occupational risk to the surgeon. There Is currently a highly effective vaccine for the prevention of hepatitis B in the host. No such vaccine is available for the other viral Infections. Tuberculosis is not a virus but also poses a risk to health care workers.

79

A 30-year-old man is in the hospital recovering from splenectomy for a ruptured spleen sustained in a motor vehicle collision. He has otherwise been healthy and was not taking medications prior to the injury. A temperature of 102°F Is noted on the second postoperative day. Vital signs are BP 130/80 mm Hg, pulse 100/minute, and respirations 18/minute. His pain is moderately controlled with morphine using patient-controlled analgesia (PCA). Breath sounds are diminished at both bases, more so on the left. His abdomen is mildly distended, soft and tender near the Incision. The incision appears to be healing without a problem. What Is the most likely cause for his fever?

A. Atelectasis and pulmonary infection

B. Peritonitis

C. Urinary tract Infection

D. Suppurative thrombophlebitis

E. Cardiac contusion

Answer: A

Early postoperative fever Is usually the result of atelectasis and subsequent pulmonary infection (Table 8-6). In this scenario, because of the close proximity of the left hemidiaphragm to the spleen, an Infiltrate In the left lower lobe of the lung Is a high probability. An adequately drained urinary tract In a young person seldom gives a high fever this early in the postoperative period. Although peritonitis from injury to a surrounding structure during the splenectomy (i.e., pancreas, stomach, or bowel) Is a possibility, It is much less likely than a pulmonary source. Cardiac contusion does not elicit a febrile response.

80

A 25-year-old man is seen in the emergency department because of a painful swollen forearm. Two days ago, he sustained a small laceration to his left forearm while clearing brush. It caused only minor discomfort until about 12 hours ago when the area around the laceration became more red and swollen. He has otherwise been healthy. He takes no medications. His temperature Is 38°C. There is a 2-cm superficial laceration on the dorsum of his left forearm with 15-cm diameter surrounding erythema that is quite tender. The edges of the erythema were marked and 20 minutes later the erythema has extended another cm beyond the mark. The most likely causative organism is

A. methicillin-resistant Staphylococcus aureus.

B. β-Hemolytic Streptococcus A.

C. Escherichia coli.

D. Streptococcus faecalis.

E. Candida albicans.

Answer: B

Although cellulitis may be caused by any organism, the most likely early organism would be β-hemolytic Streptococcus A. methicillin-resistant Staphylococcus aureus more commonly causes local Inflammation and pus formation. The other three species are rarely isolated from skin infections but more commonly are seen In infections involving the gastrointestinal tract.

81

mc type of SSI

superficial and incisional- range from simple cellulitis of the wound to overt infection of the wound bed above the fascia

82

tx superficial and incisional SSI

oral abx (most are gram pos) for cellulitis and reopening of the wound for those w infx w incisional purulent drainage and involvement of deeper tissues

83

deep incisional SSI

extend into muscle and fascia; require opening and freq surgical debridement of necrotic tissue

84

wounds at what location are at high risk for fascial necrosis and dehiscence

abdomen

85

tx deep incisional SSI

abx and cont daily local wound care

86

more severe forms of deep incisional SSI

necrotizing fasciitis, systemic infx, sepsis

87

ex of infx of organ/intracavitary space

peritonitis, intra abdominal abscess and empyema

88

surgical skin prep

povidone-iodine solution or chlorhexidine containing solutions

89

what are 2 key preventive measures

adequate tissue perforation and oxygenation

90

minimum inhibitory concentration

refers to the lowest concentration necessary to visibly inhibit growth under typical conditions

91

to insure adequate serum and tissue levels, initial abx are given how long prior to incision

1hr

92

abx for cardiac or vascular

cefazolin (ancef), cefuroxime, or vanco

93

abx for hip/knee arthroplasty

cefazolin (ancef), cefuroxime, or vanco

94

abx colon

Cefotetan, cefoxitin, ampicillin/sulbactam or ertapenem

OR

Cefazolin or cefuroxime + metronidazole

If β-lactam allergy:

Clindamycin + aminoglycoside or quinolone or aztreonam

OR

Metronidazole with aminoglycoside or

Metronidazole + quinolone

95

abx hysterectomy

cefotetan, cefazolin, cefoxitin, cefuroxime or Ampicillin/sulbactam

If β-lactam allergy

Clindamycin + aminoglycoside or quinolone or aztreonam

OR

Metronidazole + aminoglycoside or

Metronidazole + quinolone

OR

Clindamycin monotherapy

96

how long is periop abx therapy cont for

97

6 key quality indicators related to the periop manag of surgical pts that related to surgical infx according to SCIP and CMS

1. Prophylactic antibiotic delivery within 60 minutes prior to incision

2. Prophylactic antibiotics consistent with approved guidelines

3. Cessation of prophylaxis within 24 hours following surgery

4. Appropriate hair removal (clipping)

5. Glucose control for cardiac surgery

6. Normothermia for colorectal surgery

98

all infx that occur after surgical procedures are considered

nosocomial (hospital acquired)

99

fever that occurs in postop setting can be an early indication of

dev infx

100

W's of postop fever

wind (1-2d), water (2-3d), wound (3-5d), walking (5-7d), W abscess (7-10d), wonder drugs (anytime)

101

usually early and first cause of temp elev postop

lung atelectasis

102

4 major components to prevent HAP/VAP

(1) elevation of the head of the bed to 30°, (2) daily sedation vacation and assessment for weaning, (3) stress ulcer prophylaxis, and (4) venous thromboembolism prevention

103

a quantitative bronchial aspirate of what of aspirate is dx of invasive infx for VAP

>10^5 organisms/mL

104

abx use for pts in the hospital 10days

10d or immunocomp are at greater risk and abx should cover MRSA and resistant gram negative rods

105

tx for VAP

frequent airway suction;specific abx tx for 8 days

106

greatest risk factor for dev a UTI

presence of an indwelling bladder catheter

107

dx UTI

bacterial cx >100,000

108

when a postop pt w signs of infx dev a pleural effusion, the composition of fluid should be determined by

thoracentesis

109

transudative effusion

due ot inc hydrostatic forces and has low protein content

110

exudative effusion

inc permeability and has high protein content

111

what helps to differentiate exudates

LDH, glucose, pH, cell count, and gram stain

112

results of exudative effusions due to inflammation

pH 3xserum level

113

tx symptomatic pts or lg volume effusions assoc w characteristics assoc w exudate on thoracentesis

adequate drainage of the pleural space must be accomplished; abx

114

dx of exudate on imaging

ct scan w loculated rim enhancing pleural collection

115

mc cause of intra abd infx in surgical pt

perf or leakage from a hollow viscus that leads to bacterial seeding of the peritoneal cavity

116

2 response to perf or leakage of abd cavity

abscess formation or generalized peritonitis

117

primary peritonitis

spontan bacterial peritonitis that occurs wout breach of GI tract or peritoneal cavity, usually mono microbial, and seen in chronic alcoholics

118

secondary peritonitis

polymicrobial and occurs as result of spillage of gut organisms from GI tract or contamination of indwelling catheters

119

tertiary peritonitis

critically ill pts and persists or recurs at least 48hrs after apparent adequate manage, polymicrobial, and reflects a failure of host defense rather than source control

120

tx for any postop patient that demonstrates signs of systemic sepsis

broad spectrum abx

121

dx postop sepsis

blood cx, CT w PO and IV contrast*

122

blanching erythema of cellulitis caused by

group a strep and responds to penicillin tx

123

cellulitis

break in skin barrier, strep, warm to touch, diffuse erythema, tenderness, tx systemic abx and local wound care

124

furuncle, carbuncle

bacterial growth within skin glands/crypts, staph, localized induration, erythema, tenderness, swelling w purulent discharge,tx i/d, abx

125

hldradenitis suppurativa

bacterial growth within apocrine sweat glands, staph, multiple localized subcut abscesses, drainage, commonly axilla and groin, tx i/d small lesions, abx, lg needs wide local excision and skin grafting

126

lymphangitis

infx within lymphatics, strep, diffuse swelling, erythema of distal extremity w areas of inflamed streaks along lymphatic channels, tx local wound care, abx, removal fb, elevation extremity

127

gangrene, nsti's

destruction of healthy tissue by virulent microbial enzymes, strep/staph/clostridium,Necrotic skin/fascia, swelling and Induration, foul smelling discharge, crepitus with subcutaneous emphysema, frequently with toxic systemic signs and symptoms of sepsis

Radical débridement/amputation of involved tissues, aggressive local wound care with frequent débridement as necessary, parenteral broad-spectrum antibiotics

128

4 types of necrotizing soft tissue infx (NSTI)

cellulitis, fasciitis, myositis, vasculitis

129

what does non blanching erythema indicate

subdermal thrombosis of the nutrient blood supply of the skin; tx surgical debridement, high dose penicillin and clinda

130

clostridial myonecrosis or clostridial cellulitis

fulminant life threatening infx characterized by tissue necrosis and rapidly adv crepitus (gas gangrene); debridement and high dose penicillin

131

restlessness, headache, masseter muscle stiffness, and muscular contractions in area of the wound

tetanus (lockjaw); clostridium tetoni

132

tx tetanus

debridement and cleansing of all wounds in which devitalized, contaminated tissue is present

133

tetanus prone

>6hr, crush, avulsion, extensive abrasion, burns, frostbite, contaminants (soil, saliva) present

134

nontetanus prone

135

tetanus prophylaxis

unknown or

136

cause of breast abscess

staph

137

who is at higher risk for breast abscess

postpartum women

138

tx breast abscess

i/d, abx, bx

139

infx within crypts of anorectal canal and present as tender mass in perianal area

perirectal abscess

140

if perirectal abscess involves an invasive infx and results in sub cut tissue necrosis what is tx

wide debridement for salvage; colostomy diversion to avoid further soilage to area and sequelae of fecal incontinence if sphincter is involved

141

paronychia

staph infx of proximal fingernail that erupts at sulcus of the nail border

142

tx paronychia

i/d, resection of portion of embedded nail, hot soaks

143

felons

deep infx of terminal phalanx pulp space; occur after distal phalanx penetrating injuries and are tx by drainage; removal of nail may be necessary

144

neglected infections of the fingers may result in

tenosynovitis; infx extends along tendon sheath

145

organisms of bites human and animals

eikenella corrodens for humans and pasteurella for dogs/cats

146

abx for biliary tract infx

cefazolin or cefoxitin

147

mc inflammatory and infectious process in biliary tract

acute cholecystitis

148

acute peritonitis

bacteria present within the normally sterile peritoneal cavity

149

ct finding of peritonitis

upright chest roentgenogram commonly shows pneumoperitoneum beneath a hemidiaphragm with acute GI perforation and small amounts of pneumoperitoneum

150

all pts w ulcer assoc perf should be assessed for presence of

helicobacter pylori

151

abx for appendix

aerobic (e coli) and anaerobic (bacteroides fragilis) coverage

152

cause and tx fungal infx

Candida; fluconazole, ketoconazole, miconazole, nystatin

153

3 mc viral illnesses of concern for injury (needle stick)

hep B*, hep C, HIV

154

A 32-year-old man is seen in the emergency department 45 minutes after a motor vehicle collision. His only injury is a long linear laceration beginning on the left temporal forehead at the hairline and extending posteriorly for 10 cm. The edges are still bleeding briskly and the EMTs described a large amount of blood at the scene. He did not lose consciousness. His last tetanus booster was 4 years ago. Which of the following is required for tetanus prophylaxis In this patient?

A. Tetanus immune globulin only

B. Nothing further at this time

C. Tetanus toxoid only

D. Tetanus immune globulin followed by a single tetanus toxoid booster

E. Tetanus immune globulin followed by three tetanus boosters

Answer: B

Wounds prone to the development of tetanus Include those with extensive contamination with soil, deep puncture wounds from metal objects, exposure Injury complicated with frostbite, and wounds >6 hours from time of Injury (Table 8-8.). Linear lacerations In general are not prone to tetanus. The extent of blood loss does not affect the need for tetanus booster administration. The patient last received tetanus toxoid

155

A 48-year-old man Is being evaluated In the emergency department with fevers, chills, and abdominal pain for the past 24 hours. He has a history of hepatitis C infection following a blood transfusion 14 years ago for a large scalp laceration and orthopedic injuries sustained In a motor vehicle collision. He has not been to a physician for 5 years. He does not smoke or drink alcohol. He takes no medications. His temperature is 39°C and vital signs are: blood pressure (BP) 90/50 mm Hg, pulse 110/minute, and respirations 26/minute. A CT scan shows a single stone in the gallbladder that does not appear to be obstructing. The bile ducts are normal caliber and the gallbladder wall Is not thickened. There Is a moderate amount of fluid, mild small bowel distention, and stranding around the sigmoid colon as well as a small amount of free Intraperitoneal gas around the liver. An aspirate of the peritoneal fluid shows leukocytes and mixed Gram positives and negatives on Gram stain. Laboratory values show a WBC of 19,000/mm3, total bilirubin 1.2 mg/dL, and alkaline phosphatase 40 U/L. In addition to fluid resuscitation and broad-spectrum antibiotics, what is the best step in management?

A. Laparoscopic cholecystectomy

B. Long-term antibiotics only

C. Laparotomy

D. Magnetic resonance cholangiopancreatography (MRCP)

E. Endoscopic retrograde cholangiopancreatography (ERCP)

Answer: C

This patient has secondary peritonitis. This usually involves perforation of a hollow vlscus and thus involves contamination of the peritoneal cavity with multiple organisms. Gram stain and culture of the peritoneal fluid usually shows a single organism In patients with primary peritonitis and this can be treated with antibiotics without surgical Intervention. In this scenario, the CT scan shows stranding around the sigmoid and fluid and evidence of free air suggestive of a diverticulitis with fecal peritonitis. Patients with underlying liver disease are prone to gallstones and are a common finding. There Is no evidence of common bile duct obstruction that warrants further investigation since the alkaline phosphatase is normal.

156

A 42-year-old woman Is seen In the infectious disease clinic because of a small laceration. She is a surgeon and was assisting a surgical resident with a colon resection when she was accidentally cut with a scalpel blade during the procedure. She has received all required Immunizations. Antibodies against which virus could be measured in order to assess the effectiveness of the only vaccine to prevent Infection potentially transmitted from the patient to the surgeon during the operative procedure?

A. Human immunodeficiency virus

B. Hepatitis C

C. Hepatitis B

D. Cytomegalovirus

E. Tuberculosis

Answer: C

HIV, hepatitis B, hepatitis C, and cytomegalovirus are transmitted by body fluids and blood; therefore, they pose an occupational risk to the surgeon. There Is currently a highly effective vaccine for the prevention of hepatitis B in the host. No such vaccine is available for the other viral Infections. Tuberculosis is not a virus but also poses a risk to health care workers.

157

A 30-year-old man is in the hospital recovering from splenectomy for a ruptured spleen sustained in a motor vehicle collision. He has otherwise been healthy and was not taking medications prior to the injury. A temperature of 102°F Is noted on the second postoperative day. Vital signs are BP 130/80 mm Hg, pulse 100/minute, and respirations 18/minute. His pain is moderately controlled with morphine using patient-controlled analgesia (PCA). Breath sounds are diminished at both bases, more so on the left. His abdomen is mildly distended, soft and tender near the Incision. The incision appears to be healing without a problem. What Is the most likely cause for his fever?

A. Atelectasis and pulmonary infection

B. Peritonitis

C. Urinary tract Infection

D. Suppurative thrombophlebitis

E. Cardiac contusion

Answer: A

Early postoperative fever Is usually the result of atelectasis and subsequent pulmonary infection (Table 8-6). In this scenario, because of the close proximity of the left hemidiaphragm to the spleen, an Infiltrate In the left lower lobe of the lung Is a high probability. An adequately drained urinary tract In a young person seldom gives a high fever this early in the postoperative period. Although peritonitis from injury to a surrounding structure during the splenectomy (i.e., pancreas, stomach, or bowel) Is a possibility, It is much less likely than a pulmonary source. Cardiac contusion does not elicit a febrile response.

158

A 25-year-old man is seen in the emergency department because of a painful swollen forearm. Two days ago, he sustained a small laceration to his left forearm while clearing brush. It caused only minor discomfort until about 12 hours ago when the area around the laceration became more red and swollen. He has otherwise been healthy. He takes no medications. His temperature Is 38°C. There is a 2-cm superficial laceration on the dorsum of his left forearm with 15-cm diameter surrounding erythema that is quite tender. The edges of the erythema were marked and 20 minutes later the erythema has extended another cm beyond the mark. The most likely causative organism is

A. methicillin-resistant Staphylococcus aureus.

B. β-Hemolytic Streptococcus A.

C. Escherichia coli.

D. Streptococcus faecalis.

E. Candida albicans.

Answer: B

Although cellulitis may be caused by any organism, the most likely early organism would be β-hemolytic Streptococcus A. methicillin-resistant Staphylococcus aureus more commonly causes local Inflammation and pus formation. The other three species are rarely isolated from skin infections but more commonly are seen In infections involving the gastrointestinal tract.