Chapter 5 - Infection Flashcards
What is the most common immune deficiency?
Malnutrition
What is the microflora of the stomach?
Virtually sterile; some GPCs, some yeast
What is the microflora of the proximal small bowel?
10^5 bacteria, mostly GPCs
What is the microflora of the distal small bowel?
10^7 bacteria, GCPs, GPRs, GNRs
What is the microflora of the colon?
10^11 bacteria, almost all anaerobes, some GNRs, GPCs
What is the most common organism in the GI tract?
Anaerobes - Bacteroides
What is the most common aerobic bacteria in the colon?
E. coli
What is th emost common cause of gram-negative sepsis?
E. coli
What type of toxin is released by E. coli, what are its effects?
Endotoxin (lipopolysaccharide lipid A); triggers the release of TNF-alpha from macrophages, activates complement and coagulation cascade
What is the optimal glucose level in a septic patient?
100-120 mg/dL
What is the dx and tx of C. diff colitis?
Dx: fecal leukocytes in stool, C. diff toxin; Tx: oral vanco or flagyl, IV flagyl, lactobacillus
What percentage of abdominal abscesses have anaerobes?
90%
What percentage of abdominal abscesses have both anaerobic and aerobic bacteria?
80%
How many days post-op do abdominal abscesses occur?
7-10d
In which patients to antibiotics need to be started with abdominal abscesses?
DM, cellulitis, clinical signs of sepsis, fever, elevated WBC, bioprosthetic hardware
Wound infections develop in what percentage of clean (hernia) cases?
2%
Wound infections develop in what percentage of clean contaminated cases(elective colon resection w/ prepped bowel)?
3-5%
Wound infections develop in what percentage of contaminated cases (GSW to colon w/ repair)?
5-10%
Wound infections develop in what percentage of grossly contaminated cases (abscess)?
30%
What is the most common organism overall in surgical wound infections?
Staph aureus (coagulase positive)
What is exoslime?
Exopolysaccharide matrix released by staph species
What is the most common GNR in surgical wound infections?
E. coli
What is the most common anaerobe in surgical wound infections?
B. fragilis; presence indicates necrosis or abscess, implies translocation from gut
How many bacteria are needed to create a wound infection?
> 10^5, less needed if foreign body present
What are the risk factors for wound infections?
Long operations, hematoma/seroma formation, advanced age, chronic disease (COPF, renal/liver failure, DM), malnutrition, immunosuppressive drugs
What is the most common nonsurgical infection
UTI (most commonly E. coli), urinary catheters the biggest risk factor
What is the leading cause of infectious death after surgery?
Nosocomial pneumonia
What are the most common organisms in ICU pneumonia?
1 S. aureus, #2 Psuedomonas
What is th emost common class of organisms in ICU pneumonia?
GNR
What are the msot common organisms in line infections?
1 S. epidermidis, #2 S. aureus, #3 yeast
What is the line salvage rate with antibiotics?
50%, less with yeast infections
Which organisms are found in necrotizing soft tissue infectons?
Beta-hemolytic Strep (group A), C. perfringens, mixed organisms