Fiser Chapter 5 INFECTION Flashcards Preview

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Flashcards in Fiser Chapter 5 INFECTION Deck (65):
1

Stomach microflora

Virtually sterile, some GPCs and yeast

2

Proximal small bowel microflora

10^5 bacteria, mostly GPCs

3

Distal small bowel microflora

10^7 bacteria, GPCs, GPRs, GNRs

4

Colon microflora

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

5

Most common bacteria in GI tract

Bacteroides fragilis (anaerobe)

Most common aerobe: E coli

6

Postop fever and infection

Hours: NSTI
2 days: atelectasis
2-5 days: UTI (most common postop infection)
>5 days: wound infection
If within 2 days, its because of injury to bowel or invasive STI (C perfringens or beta-hemolytic strep)
7-10 days abscess

7

GN sepsis

E coli -> endotoxin (LPS lipid A) -> TNF-alpha release from macrophages -> complement activation -> coagulation cascade

8

Infection and blood glucose

Hyperglycemia often just before clinical sepsis

Early GN sepsis: decreased insulin, increased glucose
Late GN sepsis: increased insulin and glucose

9

Optimal blood glucose in sepsis

100-120 mg/dL

10

C diff colitis treatment

Oral vanc or flagyl
IV flagyl
Lactobacillus can also help
Stop or change other abx

11

Abscess bacteria

90% anaerobes
80% both anaerobes and aerobes

12

Abscess tx

I&D
Antibiotics if DM, cellulitis, clinical sepsis, fever, leukocytosis, or bioprosthetic hardware (valve, hip)

13

Expected wound infection rates

Clean: 2%
Clean contaminated 3-5%
Contaminated 5-10%
Gross contamination 30%

14

Prophylactic abx timing

24hr after OR
48hr after OR for cardiac cases

15

SSI bacteria

-Definition >/= 10^5 bacteria. Less if foreign body present.
-Most common organism S aureus (coagulase positive)

16

COPS

S aureus

17

CONS

S epidermidis

18

Exoslime

Exopolysaccharide matrix released by Staph species

19

B frag in SSI

indicates necrosis or abscess (only grows in low redox state) and/or translocation from gut

20

Risk factors for SSI

Long operation
Hematoma or seroma
Old
Chronic disease (COPD, RF, LF, DM)
Malnutrition (most common immunodeficiency)
Immunosuppression

21

Leading cause of infectious death after surgery

nosocomial PNA

22

Nosocomial PNA bacteria

1. Staph aureus
2. Pseudomonas
But GNRs #1 class of organisms in ICU PNA?

23

Line infection bacteria

1. Staph epidermidis
2. Staph aureus
3. Yeast

24

Central line cx indicative of line infection

>15 colony forming units

25

Central line infection dx and tx

Dx: >15 CFU or site looks bad
Tx: move to new site, or just PIV if possible

26

NSTI organisms

Beta-hemolytic GAS (exotoxin)
C perfringens
Mixed

27

NSTI clinical findings

Pain out of proportion
WBC >20
Thin gray drainage
Skin blistering/necrosis
Induration and edema
Crepitus or ST gas on XR
Sepsis +/-

28

Overlying skin pale red, progressing to purple with blister or bullae

NSTI

29

NSTI tx

Early debridement
High dose PCN
Broad spectrum abx if poly-organismal

30

Necrotic tissue, pain out of proportion, gram stain shows GPRs without WBCs --> myonecrosis and gas gangrene

C perfringens NSTI
Farming injury -> necrotic tissue decreases redox -> good environment for C perfringens -> alpha toxin -> myonecrosis and gas gangrene

31

C perfringens tx

High dose PCN and early debridement

32

Perineal and scrotal severe infection

-Fournier's gangrene
-GPCs, GNRs, anaerobes
-Tx: early debridement, try to preserve testicles, antibiotics

33

Tortuous abscess in cervical, thoracic, or abdominal area

Actinomyces
Tx: drain and PCN G

34

Actinomyces abx

Penicillin G

35

Pulmonary and CNS symptoms, branching bacteria

Nocardia
Drain and bactrim

36

Nocardia abx

Bactrim

37

Candida abx

Fluconazole; sometimes anidulafungin for severe infections

38

Aspergillosis abx

Voriconazole

39

Histoplasmosis abx

Mississippi and Ohio River valley
Pulmonary symptoms
Tx: liposomal amphotericin for severe infection

40

Cryptococcus

CNS symptoms in AIDS
Tx: liposomal amphotericin for severe infection

41

Coccidioidomycosis

Southwest, pulm symptoms
Tx: liposomal amphotericin for severe infection

42

Primary SBP risk factor

43

SBP organisms

E coli
Streptococcus
Klebsiella
Fluid cultures often negative
PMNs>500 cells/cc diagnostic

Secondary bacterial peritonitis: polymicrobial (B frag, E coli, enterococcus)

44

SBP ppx and tx

ppx: Fluoroquinolones (norfloxacin)
tx: Ceftriaxone

45

Secondary bacterial peritonitis

Perforated viscus
Polymicrobial
Need ex-lap

46

Risk of HIV if needle stick from positive patient

0.3%

47

Risk of HIV if mucous membrane exposure

0.1%

48

HIV exposure ppx

Zidovudine and ritonavir (RTI and PI)

49

Most common causes for ex-lap in HIV patients

1. Opportunisitic infection (CMV)
2. Neoplastic disease

50

AIDS patient with pain, bleeding, and perforation

CMV colitis
Most common intestinal manifestation of AIDS

51

Most common neoplasm in AIDS

Kaposi's sarcoma

52

HIV lymphoma sites

1. Stomach
2. Rectum
Mostly NHL (B cell)
Tx: chemo

53

GIB in HIV patient

LGIB more common: CMV, bacterial, HSV
UGIB: Kaposi's sarcoma, lymphoma

54

CD4 counts

Normal: 800-1200
Symptomatic HIV: 300-400
Opportunistic infection:

55

Risk of HepC with blood transfusion

.0001%

56

HepC infection types

Chronic 60%
Cirrhosis 15% (interferon may help prevent)
HCC 1-5%

57

Brown recluse spider bite infection tx

Dapsone
May need resection of area and skin graft for large ulcers later

58

Acute septic arthritis bacteria and empiric tx

Gonococcus, staph, H influenzae, strep
Drainage
Vanc/ceftriaxone

59

DM foot infection bacteria and tx

Mixed staph, strep, GNRs, anaerobes
Tx: Broad spectrum abx, e.g. Unasyn

60

Cat/dog/human bite bacteria and tx

Polymicrobial
Eikenella only in human bites -> permanent joint injury
Pasteurella multocida in cat and dog bites
Tx: broad spectrum abx, e.g. Augmentin

61

Impetigo, erysipelas, cellulitis, folliculitis organism

staph and strep most commonly

62

Furuncle boils organism and tx

S epidermidis or S aureus
Tx: drainage +/- abx

63

Carbuncle

multiloculated furuncle

64

Peritoneal dialysis catheter infection bacteria and tx

-S aureus and S epidermidis most commonly
-Fungal (hard to treat)

Tx: intraperitoneal vanc/gentamicin; increased dwell time and intraperitoneal heparin may help; removal if peritonitis lasts >4-5 days

65

Sinusitis risk factors, bacteria, dx, tx

Nasoenteric tubes
Intubation
Severe facial fractures

Usually polymicrobial

HCT air-fluid levels in sinus

Tx: Broad-spectrum abx, rarely percutaneous tap