Chapter 5 - Infection Flashcards Preview

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Flashcards in Chapter 5 - Infection Deck (81)
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2
Q

What is the most common immune deficiency?

A

Malnutrition

3
Q

What is the microflora of the stomach?

A

Virtually sterile; some GPCs, some yeast

4
Q

What is the microflora of the proximal small bowel?

A

10^5 bacteria, mostly GPCs

5
Q

What is the microflora of the distal small bowel?

A

10^7 bacteria, GCPs, GPRs, GNRs

6
Q

What is the microflora of the colon?

A

10^11 bacteria, almost all anaerobes, some GNRs, GPCs

7
Q

What is the most common organism in the GI tract?

A

Anaerobes - Bacteroides

8
Q

What is the most common aerobic bacteria in the colon?

A

E. coli

9
Q

What is th emost common cause of gram-negative sepsis?

A

E. coli

10
Q

What type of toxin is released by E. coli, what are its effects?

A

Endotoxin (lipopolysaccharide lipid A); triggers the release of TNF-alpha from macrophages, activates complement and coagulation cascade

11
Q

What is the optimal glucose level in a septic patient?

A

100-120 mg/dL

12
Q

What is the dx and tx of C. diff colitis?

A

Dx: fecal leukocytes in stool, C. diff toxin; Tx: oral vanco or flagyl, IV flagyl, lactobacillus

13
Q

What percentage of abdominal abscesses have anaerobes?

A

90%

14
Q

What percentage of abdominal abscesses have both anaerobic and aerobic bacteria?

A

80%

15
Q

How many days post-op do abdominal abscesses occur?

A

7-10d

16
Q

In which patients to antibiotics need to be started with abdominal abscesses?

A

DM, cellulitis, clinical signs of sepsis, fever, elevated WBC, bioprosthetic hardware

17
Q

Wound infections develop in what percentage of clean (hernia) cases?

A

2%

18
Q

Wound infections develop in what percentage of clean contaminated cases(elective colon resection w/ prepped bowel)?

A

3-5%

19
Q

Wound infections develop in what percentage of contaminated cases (GSW to colon w/ repair)?

A

5-10%

20
Q

Wound infections develop in what percentage of grossly contaminated cases (abscess)?

A

30%

21
Q

What is the most common organism overall in surgical wound infections?

A

Staph aureus (coagulase positive)

22
Q

What is exoslime?

A

Exopolysaccharide matrix released by staph species

23
Q

What is the most common GNR in surgical wound infections?

A

E. coli

24
Q

What is the most common anaerobe in surgical wound infections?

A

B. fragilis; presence indicates necrosis or abscess, implies translocation from gut

25
Q

How many bacteria are needed to create a wound infection?

A

> 10^5, less needed if foreign body present

26
Q

What are the risk factors for wound infections?

A

Long operations, hematoma/seroma formation, advanced age, chronic disease (COPF, renal/liver failure, DM), malnutrition, immunosuppressive drugs

27
Q

What is the most common nonsurgical infection

A

UTI (most commonly E. coli), urinary catheters the biggest risk factor

28
Q

What is the leading cause of infectious death after surgery?

A

Nosocomial pneumonia

29
Q

What are the most common organisms in ICU pneumonia?

A

1 S. aureus, #2 Psuedomonas

30
Q

What is th emost common class of organisms in ICU pneumonia?

A

GNR

31
Q

What are the msot common organisms in line infections?

A

1 S. epidermidis, #2 S. aureus, #3 yeast

32
Q

What is the line salvage rate with antibiotics?

A

50%, less with yeast infections

33
Q

Which organisms are found in necrotizing soft tissue infectons?

A

Beta-hemolytic Strep (group A), C. perfringens, mixed organisms

34
Q

Organisms found in necrotizing faciitis?

A

Beta-hemolytic Strep, can be polyorganismal

35
Q

What are the signs of necrotizing fasciitis?

A

Overlying skin pale red, progress to purple with blisters; thin, gray, foul-smelling drainage, crepitus

36
Q

What is the treatment of necrotizing fasciitis?

A

Early debridement, high-dose penicillins, broad spectrum if thought to be polyorganismal

37
Q

How does necrotic tissue set up an environment for C. perfringens infections?

A

Decreases oxidation-redux potential

38
Q

C. perfringens has what type of toxin?

A

alpha toxin

39
Q

What will a gram stain show with C. perfringens infection?

A

GPRs without WBCs

40
Q

What organisms are found in Fournier’s gangrene?

A

Mixed organisms (GPCs, GNRs, anaerobes)

41
Q

When do you cover for fungal infection?

A

Positive blood cultures, 2 sites other than blood, 1 site with severe symptoms, endophthalmitis, pts on prolonged bacterial abx without improvement

42
Q

Type of abscess caused by Actinomyces (not a true fungus)?

A

Tortuous abscesses in cervical, thoracic, abdominal areas; most commonly with pulmonary symptoms

43
Q

Treatment for Actinomyces?

A

Drainage and penicillin G

44
Q

Sympoms wtih Nocardia (not a true fungus)?

A

Pulmonary and CNS

45
Q

Treatment for Nocardia?

A

Drainage and sulfonamides (bactrim)

46
Q

Symptoms with Histoplasmosis?

A

Pulmonary most common; Mississippi and Ohio River valleys

47
Q

Treatment for Histoplasmosis?

A

Amphotericin for severe infections

48
Q

Symptoms with Cryptococcus?

A

CNS most common

49
Q

Treatment for Cryptococcus?

A

Amphotericin for severe infections

50
Q

Symptoms with Coccidioidomycosis?

A

Pulmonary; Southwest

51
Q

Treatment for Coccidioidomycosis?

A

Amphotericin for severe infections

52
Q

Spontaneous (primary) bacterial peritonitis is secondary to what?

A

Decreased host defenses (intrahepatic shunting, impaired bactericidal activity in ascities); NOT due to transmucosal migration

53
Q

SBP is caused by which organisms?

A

Monobacterial: 50% E. coli, 30% Strep, 10% Klebsiella

54
Q

What test on the tap is diagnostic of SBP?

A

PMNs > 500cells/cc

55
Q

Treatment for SBP?

A

Ceftriaxone or other 3rd generation cephalosporin

56
Q

What is used for short term prophylaxis against SBP?

A

Fluoroquinolones (cipro)

57
Q

What causes secondary bacterial peritonitis?

A

Intra-abdominal source (transmucosal migration, perforated viscus); polymicrobial, B. fragilis, E. coli, Enterococcus

58
Q

Treatment for secondary bacterial peritonitis?

A

Laparotomy

59
Q

Chance of contracting HIV with HIV+ blood transfusion?

A

70%

60
Q

Chance of infant contracting HIV from positive mother?

A

30%

61
Q

Chance of contracting HIV from needle stick?

A

0.3%

62
Q

Chance of contracting HIV from mucous membrane exposure?

A

1%

63
Q

What is the most common cause for laparotomy in HIV patients?

A

Opportunistic infections (CMV most common)

64
Q

What is the most common intestinal manifestation of AIDS?

A

CMV colitis (pain, bleeding or perforation)

65
Q

Most common organ affected by lymphoma in HIV patients?

A

Stomach, followed by rectum (mostly Non-Hodgkin’s, 70% B cell)

66
Q

What causes GI bleeds in HIV patients?

A

Upper: Kaposi’s sarcoma; Lower: CMV, bacterial, HSV (lower more common)

67
Q

What are the CD4 counts in normal, symptomatic disease, and opportunistic infections?

A

Normal: 800-1200; Symptomatic disease: 300-400; Opportunistic infections: 200

68
Q

Chronic infection occurs in what % of Hep C patients?

A

60%

69
Q

Cirrhosis occurs in what % of Hep C patients?

A

15% over 20y

70
Q

HCC occurs in what % of Hep C patients?

A

1-5%

71
Q

Treatment of brown recluse spider bites?

A

Dapsone; may need resection of area/skin graft for large ulcers

72
Q

What organisms cause acute septic arthritis?

A

Gonococcus, staph, H. flu, strep

73
Q

Treatment of acute septic arthritis?

A

Drainage, 3rd-gen cephalosporins and vanco

74
Q

What organisms cause diabetic food infections?

A

Mixed staph, strep, GNRs, anaerobes

75
Q

Treatment of diabetic foot infections?

A

Broad spectrum abx: Unasyn, Zosyn

76
Q

What organism is found in human bites?

A

Eikenella, can cause pernament joint inujury

77
Q

What organism is found in dog/cat bites?

A

Pasturella multocida

78
Q

Treatment for human/dog/cat bites?

A

Broad-spectrum abx: Augmentin

79
Q

Most common organisms for impetigo, erysipelas, cellulitis, folliculitis?

A

Staph and strep

80
Q

Most common organisms in PD cath infections?

A

S. aureus, S. epidermidis

81
Q

Treatment of PD cath infections?

A

Intraperitoneal vanco/gent; removal of catheter for peritonitis that lasts for 4-5d

82
Q

Risk factors for sinusitis?

A

Nasoenteric tubes, intubations, facial fractures