ID Flashcards
(19 cards)
Asplenic patients at risk for
Strep pneumo, H flu, Neisseria
Babesia, plasmodium
CRBSI definition
same organism from periph blood culture and catheter tip
-Quant (3x greater in central) or differential time to pos (2h earlier in central)
VAP
pneumonia after 48h of ETT not incubating at time of intubation
VAC
IVAC
Possible PNA
Probable PNA
VAC-ventilator associated condition
-2d of stability, followed by 2d of (new resp deterioration) increased PEEP >3 or FiO2 inc 20
IVAC- Infection related VAC
-VAC + Temp <36 or >38, WBC <4k or >12k and new antibiotic for 4d within 2d of VAC (“New resp deterioration due to infection)
Possible Pneumonia
-IVAC + gram stain >25 PMN and <10 epi
Probable pneumonia
-IVAC plus gram stain >25PMN and <10epi and endotracheal aspirate >10^5 or BAL >10^4
3 mechanisms of beta-lactamase
- ESBL
- chromosomal AmpC
- Carbapenemase
Order to test for CDI
- NAAT of organism (more sensitive, detects genes including for toxin but genes and not actual toxin)
- Confirmatory test with toxin assay by EIA (actual pathogenic factor leading to infection) before calling in CDI
Tx choices for KPC
- Ceftaz-avibactam
- meropenem-vaborbactam
- colistin
- tigecycline
- aminoglycoside may retain some activity, but not good choice for pulmonary infections
Duration of Therapies in Infection
- HAP/VAP 7d is equal to longer course
- Gram negative bacteremia, afebrile, HDS for 48h, adequate source control: RCT , 7d noninferior to 14d
- can step down to oral by 5d if clinical response within 5d
- S aureus has endothelial adhesiveness- minimum of 14d even in situations where uncomplicated bacteremia line-associated)
- Enterococcus has endothelial adhesiveness, communicty acquired much more likely to be associated with endocarditis than nosocomial
- candidemia- 2 weeks if metastatic complications excluded (including endopthalmitis) after clearing cultures
Pharmacokinetics for abx
Hydrophilic- time-dependent killing
Hydrophobic/lipophilic- concentration-dependent killing
Abx properties
Hydrophilic- time-dependent killing (beta-lactams, vanc)
-limited penetration of lung, less time over MIC
-prolonged or continuous infusions of beta-lactam for pneumonia. Leads to higher clinical cure rates
-lower mortality in sepsis with prolonged infusion of antipseudomonal beta-lactam
Hydrophobic/lipophilic- concentration-dependent killing (fluroquinolones, macrolides, and linezolid)
-better epithelial: serum ratio
-cidal vs static seems to have no major baring. May be relevant for certain infections: neutropenia, endocarditis, meningitis.
CT before LP if: (1 present)
- Immunocompromised
- History of CNS disease
- alterred level of consciousness or new seizure, new focal deficit
- papilledema
LP findings
Bacterial:
WBC usually >1000, glu <40, protein 100-500 (if very high, think TB)
Listeria coverage if over age:
50yo
CONS in bacteremia:
- which should be treated like SA
- which should prompt colonoscopy
- Strep gallolyticus (previously bovis) need colonoscopy
- Staph lugdunensis is similar to SA in terms of rate of infective endocarditis with bacteremia
- should be managed similar to S aureus
- Staph epidermidis and S haemolyticus- if uncomplicated catheter-related bloodstream infection- 5-7d of abx if catheter removed
Defic in cell-mediated immunity
Intracellular
-TB, Salmonella, Listeria, Nocardia, Rhodococcus
Strep gallolyticus
Meningitis- look for endocarditis and colon cancer
Bacterial organisms linke to colon cancer
Clostridium septicum (along with strep gallolytics)
When to give steroids in PJP
PaO2 <70 or A-a gradient >35
PsA Pneumonia Treatment
Double coverage just provides increased likelihood of covering. No benefit to 2abx. No synergy.
7d is adequate.
