Fiser Chapter 5: Infection Flashcards
Most common immune deficiency leading to infection.
Malnutrition
Microflora in:
Stomach; proximal small bowel; distal small bowel; colon
Stomach: sterile, some GPC, some yeast
Proximal small bowel: GPC (10^5)
Distal small bowel: GPC, GPR, GNR (10^7)
Colon: 10^11 (anaerobes; some GNR, GPC)
Most common anaerobe in the colon
Bacteroides fragilis
Most common aerobic bacteria in the colon
E. coli
Which are more common organisms in the GI tract: aerobic or anaerobes?
Anaerobes
Anerobes lack these enzymes making them vulnerable to oxygen radicals.
Superoxide dismutase
Catalase
Most common organism that causes GN sepsis
E. coli
Pathophysiology of GN sepsis
Endotoxin (Lipopolysaccharide lipid A) is released; triggers release of TNF-alpha; released from macrophages, triggers inflammation, activates complement, actives coagulation cascade
Describe hyperglycemia in early vs. late GN sepsis
Early: Decreased insulin; impaired utilization
Late: insulin resistance
T/F Hyperglycemia occurs just before the patients becomes clinically septic.
True
Optimal glucose level in a septic patient
80-120
Diagnostic test for C. diff
ELISA for Toxin A
What do you use to treat C. diff in pregnancy?
PO Vanc
Treatment for fulminant C. diff colitis?
Total colectomy with end ileostomy
What percentage of abdominal abscesses have anaerobes?
90%
What percentage of abdominal abscesses have both anaerobes and aerobes?
80%
When do intra-abdominal abscesses usually occur?
7-10 days post-op
When are antibiotics indicated for intra-abdominal abscesses?
Diabetes, cellulitis, sepsis, fever, prosthetic hardware
4 classes of surgical operation
Clean: hernia (2%)
Clean-contaminated: elective colon-resection with prepped bowel (3-5%)
Contaminated: GSW colon with repair (5-10%)
Gross contaminated: abscess (30%)
Most common SSI organism
Staph aureus (coag-positive)
Is staph epi coag positive or negative?
Negative
What is the exoslime released by staph species?
Exo-polysaccharide matrix
Most common GNR in surgical wounds?
E. coli
Most common anerobe in surgical wound infection?
B. fragilis
What does recovery of B. fragilis from surgical wound infection indicate?
Necrosis, abscess, gut translocation
How many bacteria required for SSI?
10^5 (less if foreign body)
Risk factors for wound infection
Long operation; hematoma or seroma formation; advanced age; chronic disease (COPD, ESRD, liver failure, DM), malnutrition, IS drugs
Most common infection in surgery patients
UTI; biggest risk factor is urinary catheter; most commonly E. coli (GNR)
Leading cause of infectious death after surgery; most common organisms
Nosocomial pneumonia
- Related to length of ventilation, aspiration
- S. aureus, Pseudomonas, E. coli
- GNR #1 cause in ICU patients
3 most common line infections
- S. epi
- S. aureus
- Yeast
What % of infected lines can be salvaged?
50%
2 most common causes of necrotizing soft tissue infections
GAS; MRSA (exotoxins); C. perf
Or mixed
Risk factors for necrotizing soft tissue infections
DM, poor Q, immunocompromised
Signs/symptoms of necrotizing soft tissue infection
Pain out of proportion to skin, mental status changes, WBC >20, thin gray drainage, blistering/necrosis, induration/edema, crepitus, soft tissue gas on X-ray
T/F Nec fasc spreads along fascial planes
True
Which necrotizing organism has alpha toxin?
C. perf
Where does Fournier’s gangrene occur anatomically?
Perineal, scrotal
Most common anatomic location of aspiration pneumonia? Most common organism?
RLL (sup seg); S. pneumonia MC organism
Test with highest sensitivity for OM?
MRI
Treatment for brown recluse spider bite?
Oral dapson; avoid early surgery
Treatment for acute septic arthritis? Most common organisms?
Drainage, CTX + Vanc
- Gonococcus, staph, H. flu, strep
Most common cause of cat/dog/human bite?
S. pyogenes
What bacteria is found in human bites?
Eikenella; can cause joint damage
What bacteria can be found in cat/dog bites
Pasturella multocida
Treatment for cat, dog, human bites?
Augmentin
Most common cause of impetigo, erysipelas, cellulitis, folliculitis
Staph (MC), strep
Diffrerence beteween furuncle and carbuncle
Furuncle: boil (S. epi/S. aureus)
Carbuncle: Multi-loculated furunce
Symptoms of PD catheter infection
Cloudy fluid, abdominal pain, fever (monobacterial)
MCC PD catheter infections
S. epi (#1), S. aureus, Pseudomonas; fungal difficult to treat
Treatment PD catheter infection
IP Vanc/Gent; increased dwell time, IP heparin; IV ABX not as helpful
When do you remove PD catheter for infection?
After 4-5 days of infection
What about fecal peritonitis in PD catheter infection?
Ex lap to find perforation
Which infections require removal of PD catheter infections
Pseudomonas, fungal, tuberculous
Treatment of sinusitis
BS ABXB; rare to have to tap sinus for systemic illness
Best prevention strategy for nosocomial infections
Hand washing
Highest risk patients for nosocmial infections
Burn patients
Best practices to prevent surgical site infections
Clippers pre-op (over razor) Glucose 80-120 PaO2 -- 100% FiO2 Patiente warm Chlorhexidine prep with iodine-impregnated drapes
Yellow sulfer granules on Gram stain; symptoms, treatment
Actinomyces; pulm symptoms
- Drainage and PCN G
Treatment of Nocardia
Drainage and Bactrim
MCC fungemia
Candida
Tx: Fluconazome
Treatment for Candiduria
Remove foley catheter
Treatment for aspergillosis
Voriconazole
Treatment of Histoplasmosis (MS and Ohio River Valleys)
Ampho
Treatment for Cryptococcus
Ampho
Treatment of Coccidiomycosis
Ampho
MCC SBP
E coli, Strep, Klebsiella
How many PMN’s needed for diagnosis of SBP?
250
Treatment SBP?
CTX
Polymicrobial SBP?
R/O intra-abdominal source
PPX SBP
q weekly flouroquinolones
T/F HIV is an RNA virus with reverse transcriptase
True
T/F HIV anti-virals should be given within 1 hour of exposure
True
Most common indication for laparotomy in HIV patients
CMV; second most common is lymphoma
Most common intestinal manifestation of AIDS
CMV colitis; pain, bleeding, perforation
Most common neoplasm in AIDS
Kaposi’s sarcoma
Most common location of lymphoma in HIV patients
Stomach, then rectum
- NHL (B; cell)
UGI vs. LGI bleed in AIDS patients
UGI: Kaposi, lymphoma
LGI: CMV, bacterial, HSV
CMV is transmitted by (this cell)
Leukocytes
Most common infection in transplant patients?
CMV
Most common manifestation of CMV infection
Febrile mononucleosis
Most common deadly form of CMV
CMV pneumonititis
CMV biopsy
Cellular inclusion bodies; CMV serology
Treatment of CMV
Ganciclovir; CMV immune globulin (neg patient receive positive organ)