Infective Endocarditis Flashcards
def
infection of intracardiac endocardial structures (heart valves)
what are the organisms which cause infective endocarditis
1 streptococci (40%) -streptococcus viridans -streptococcus bovis 2 staphylococci (35%) -s. aureus -s. epidermidis 3 enterococci (20%) -enterococcus faecalis 4 HACEK
in which people would infective endocarditis caused by s. epidermidis be common
IV drug users
what does HACEK stand for
rarer causes of infective endocarditis haemophilus actinobacillus cardiobacterium eikenella kingella
aetiology
1 vegetations form as a result of organisms lodging on the heart valves in bacteraemia
2 vegetations destroy the valve leaflets
3 activation of the immune system causes formation of immune complexes leading to cutaneous vasculitis, glomerulonephritis or arthritis
associations/risk factors
1 abnormal valves -congenital -post-rheumatic -calcification -degeneration 2 prosthetic heart valves 3 turbulent flow (patent ductus arteriosus) 4 recent dental work
what would s. bovis be associated with
GI malignancy
epi
incidence is 16-22 per million PA (UK)
history
1 fevers with sweats/rigors
2 arthralgia/myalgia
3 confusion
4 ask about recent dental surgery or IV drug use
examination
1 pyrexia 2 tachycardia 3 signs of anaemia (conjunctival pallor) 4 new regurgitant murmur 5 hand signs
which heart valves are most commonly affected in infective endocarditis
mitral> aortic> tricuspid> pulmonary
what hand signs are there in infective endocarditis
1 splinter haemorrhages
2 clubbing
3 janeway lesions (painless, palmar)
4 oslers nodes (painful)
investigations
1 bloods -FBC (high neutrophil, normocytic anaemia) -high ESR + CRP -rheumatoid factor positive 2 urinalysis -microscopic haematuria -proteinuria 3 blood culture 4 echo -TOE is more sensitive than TTE for detection of endocarditis 5 ECG -abscesses can cause conduction changes
what is TOE
transoesophageal echocardiogram
what is the classification used to diagnose endocarditis
Dukes’ classification
what are the diagnosing criteria for Dukes’ classification
2 major
1 major + 3 minor
5 minor
what are the major Dukes criteria
1 positive blood culture in 2 samples 2 positive echo -vegatation -abscess -prosthetic valve dehiscence (wound rupture along the surgical incision) -new valve regurgitation
what are the minor Dukes criteria
1 pyrexia 2 risk factors (abnormal valves, IV drug use, dental surgery) 3 positive blood culture (but not major) 4 positive echo (but not major) 5 vascular signs
management
antibiotics for 4-6wks (>6wks for prosthetic valve endocarditis)
urgent valve replacement if poor response to antibiotics or deterioration
what antibiotics are used with clinical suspicion of infective endocarditis
benzylpenicillin + gentamicin
what antibiotics are used for streptococci infective endocarditis
benzylpenicillin + gentamicin
what antibiotics are used for staphylococci infective endocarditis
oxacillin or vancomycin + clindamycin
what antibiotics are used for staphylococci prosthetic valve infective endocarditis
benzylpenicillin + gentamicin
what antibiotics are used for enterococi infective endocarditis
ampicillin + gentamicin
what antibiotics are used for HACEK infective endocarditis
ceftriaxone or ampicillin
when is antibiotic prophylaxis given in infective endocarditis
1 history of infective endocarditis
2 dental procedure (2g oral amoxacillin)
3 prosthetic heart valve replacement
complications
1 heart failure 2 renal failure 3 glomerulonephritis 4 arterial emboli from vegetations 5 aneurysms
prognosis
fatal if untreated
treated 15-30% mortality
