Bacteremia and Endocarditis Flashcards
Gram (+), lancet-shaped diplococci that cause CA-pneumonia
Strep Pneumoniae
bacteremia
bacterial infection within the blood
-intermittent or continuous
S. aureus vs. S. epidermis
S. aureus is more likely to be a pathogen, so your approach should be different.
S. epidermis is a common contaminant (esp. if taken from IV port/catheter)
correct blood culture technique (4 things)
- obtain prior to starting Abx
- take three sets of cultures
- do not draw through IV catheters
- one aerobic bottle and one anaerobic bottle
When should additional sets of blood cultures be ordered?
1) if pt continues to have fevers
2) to document clearance of S. aureus bacteremia
3) when you suspect endocarditis
likely bacteria in infective endocarditis =
staphylococci and streptococci because they have surface proteins that make them more likely to attach -S. aureus (32%) -coag (-) staph 16% (mechanical valve) -strep viridan = 23% strep bovis = 5% - E. faecalis (GU procedures)
local tissue damage in IE
leads to valve destruction (regurg and heart failure) and extension into the perivalvular area
systemic emboli of IE can go:
to the coronary vessels, brain, kidneys, spleen, liver, lungs (rt. sided valves)
IE and IVDU
60-70% due to S. aureus
Cardiac manifestations of IE
-valvular regurg, heart failure, conduction abnormalities
neurologic manifestations of IE
- emboli to the brain, abscesses, mycotic aneurysms w/ bleeding
- sxs: MSC, seizure, encephalopathy, meningitis
Diagnostic findings of IE
increased ESR and CRP
EKG conduction abnl
Echo may be negative
multiple (+) blood cultures
If endocarditis with (-) culture, most likely because…
prior Abx administration
-or HACEK group or fastidious organisms
Modified Duke Criteria: Majors
1) microbiologic - continuous bacteremia
2) echocardiographic
3) serologic (Q fever)
Modified Duke Criteria: Minors
1) predisposing heart condition
2) IVDU
3) fever >38
4) vascular phenomena
5) immunologic phenomena
6) other (+) culture
