Bacteremia and Endocarditis Flashcards
gram positive bacteria, appears as lancet-shaped diplococci
strep pneumo
T/F: Pneumonia always causes bacteremia
False. It happens but not always.
Bacteremia during pneumonia is what type of bacteremia?
intermittent bacteremia
2 types of intermittent bacteremia
1-after a procedure
2-in the setting of a bacterial infection, eg pneumonia, pyelonephritis, skin infection
How many SETs (one aerobic bottle, one anaerobic) of bottles should be drawn from a patient, typically, to evaluate for bacteremia/sepsis?
three. try to draw from different sites, and from veins instead of indwelling lines/catheters.
T/F - Staph epidermitis is a common cause of continuous bacteremia
False. It is a common contaminant. Very rarely acts as a pathogen.
3 ways to reduce false positive cultures in blood draws.
- use more than one set
- proper aseptic technique
- avoid drawing blood thru catheters
T/F: In cases of clinically significant bacteremia, blood cultures usually turn positive within 48 hours.
True
3 situations in which additional sets of blood cultures should be ordered fr bacteremia.
- pt continues to have fevers despite therapy
- to document clearance of bacteremia with Staph aureus (even if no symptoms presently)
- when endocarditis is suspected
definition of continuous bacteremia
bacteria present in the blood for long periods of time, reflecting an endovascular infection
T/F - Endocarditis always involves the valves of the heart.
False. It can involve other surfaces of the heart. But most commonly the valves.
Which two bacteria have surface proteins which make them more likely to attach to valves?
staphylococci and streptococci
T/F: endocarditis from E.Coli is common
False. Bacteremia from E Coli is common, but it doesn’t attach to the valves well, hence it is very rare.
What are the 3 most common organisms (or groups of org’s) that cause endocarditis
1- S. aureus
2- Viridans Strep
3 - Coagulase negative staph (especially mechanical valves)
5 risk factors for endocarditis
- underlying structural heart disease
- IV drug use
- prosthetic valve
- catheter-related bacteremia
- prior episode of infective endocarditis
Iv drug users often get which type of endocarditis?
-60-70% Staph aureus
3 main complications of endocarditis
- local tissue destruction in heart (valve abscess)
- continuous bacteremia
- embolic lesions
Clinical manifestations of endocarditis
Systemic: fever, myalgia, night sweat, wt loss.
Cutaneous:
rash, splinter hemorrhages
Ocular hemorrhages.
What is the leading cause of death from endocarditis?
heart failure
What is the leading surgical indication for endocarditis?
heart failure
renal manifestations of endocarditis
microscopic hematuria
elevated creatinine
(caused by immune complex definition and infarcts)
Importance of echocardiogram in endocarditis
It can help you find abnormalities in the valve. HOWEVER often negative in endocarditis! Don’t give up on the diagnosis if the echo is negative!
3 key diagnostic findings for endocarditis
- highly elevated ESR and CRP
- EKG abnormalities
- positive blood cultures
Culture negative endocarditis is most often due to ?
giving antibiotics before drawing blood.
previously was due to unculturable strains
What is the Duke Criteria for infective endocarditis?
You must have one major criterion or 3 minor criterion for diagnosis.
Major criteria for Duke Criteria endocarditis diagnosis.
- positive blood culture with organism typical of endocarditis
- positive echocardiographic signs
- serologic evidence of Coxiella (Q fever)
Duke endocarditis criteria - minor criteria (6)
- predisposing heart condition
- IV drug Use
- fever >38C
- Vascular complications: emboli, aneurysm
- immunologic phenomena - Osler’s nodes, roth spots
- culture not meeting major criterie
Treatment for endocarditis- type of antibiotics, administration
4+weeks of IV antibiotics!!!
-BactericCIDAL antibiotics needed!
No pills - concentrations don’t get high enough in the blood!
Level of heart failure required for surgical indication
NYHA 3 or 4
5 indications for surgical treatment for endocarditis.
- Heart failure
- fungal endocarditis
- perivalvular extension
- persistent bacteremia despite adequate antibiotic
In which conditions should you give antibiotic prophylaxis before dental procedures (to prevent endocarditis)?
only 3 conditions (high risk, with conditions allowing for vegetation in the heart)
- prosthetic cardiac valve
- previous endocarditis
- congenital heart disease
4 types of endoVASCULAR infections
-infection of vascular graft
-infection of central venous catheters
-suppurative thrombophlebitis
endarteritis
3 main complications of endocarditis
- systemic dissemination
- immune complexes
- emboli
