38 Cardiology infections Flashcards
IE involves endothelial linings of the heart, usually including heart valves. Majority have pre-existing heart defect e.g rheumatic fever/ congenital/ prosthetic valve/ cardiac device
How do vegetations form?
Route of entry into bloodstream e.g dental work, urinary tract, GI tract
Organisms bind to fibrin-platelet vegetations on damaged valves/ endothelium
Multiply further, as protected by vegetation
Slow process, so from bacteraemia to symptoms can take 5 weeks
Which organisms cause native valve IE?
Most commonly affects aortic/ mitral valves
30% of infections can be classified as HAI - due to lines/ procedures
Staph aureus 30%
Coagulase negative staph 5%
Streptococci -
- viridans species - mutans/ sanguinis/ mitis 40%
- Group D - enterococcus 10%
Gram neg rods 5%
HACEK 5%
Candida
Culture negative 5-25%
Staph aureus is the most common in IVDU 70%
What are less common causes of native valve IE?
blood culture negative
Strep pneumoniae
Coagulase negative staph
If blood cultures negative test for - Haemophilus influenzae Brucella Bartonella Coxiella Chlamydia Legionella HACEK (if grown in wrong medium) Trephonema whipplei
What are causes of prosthetic valve IE?
Often divided into early (within 1 year of insertion) and late infection. There are microbiological differences in aetiology
Staph epidermidis 30%
Staph aureus 40%
Strep viridans <5%
Pseudomonas
Serratia marcescens
Diptherioids
HACEK
Fungi
Most patients with IE with have fever and murmur.
What are the modified duke criteria?
Major -
- typical organism demonstrated in culture or in vegetation in 2 separate blood cultures - Staph/ Strep/ HACEK
- one positive blood culture for coxiella burnetti
- vegetation showing endocardial involvement
Minor -
- fever
- predisposition - IVDU, predisposing heart condition
- vascular phenomena - Janeway lesions, septic emboli Splinter haemorrhages
- immunologic phenomena - Oslers nodes, Roth spots, glomerulonephritis (haematuria)
- microbiological evidence - blood culture is not typical for IE
Definite IE -
2 major
1 major 3 minor
5 minor
Possible IE -
1 major 1 minor
3 minor
What are investigations for IE?
Blood cultures - 3 sets, at different sites, with 6 hours between them
Urinalysis - haematuria
TTE/ TOE
Consider investigation for rarer organisms
May need PET/CT scan - look for uptake around valves. Only use if prosthetic valve been in situ for >3 months
IE has mortality rate between 20-50%, why is this?
Late presentation
Vegetation resistant to host defenses/ antibiotics
Vegetation has high bacterial desnity
What is treatment for IE?
Native valve - indolent presentation
Native valve - sepsis
Native valve - indolent presentation
- Amoxicillin 2g 4 hourly
- gentamicin 1mg/kg BD
Native valve - sepsis
- vancomycin
- gentamicin 1mg/kg BD
What is treatment for IE?
Prosthetic valve
Vancomycin
Gentamicin 1mg/kg BD
Rifampicin 600mg PO/IV BD
Proven Staphyloccal endocarditis (MSSA)
What is treatment?
Native valve
Prosthetic valve
Native valve
- flucloxacillin 2g IV QDS
Prosthetic valve
- flucloxacillin 2g QDS
- gentamicin 1mg/kg BD
- rifampicin 600mg BD
Switch flucloxacillin for vancomycin if MRSA
Proven Streptococcal endocarditis
What is treatment?
Native valve/ prosthetic valve is the same
Benzylpenicillin 1.2g 4 hourly
or
Ceftriaxone 2g OD - suitable for OPAT
Proven enterococcal endocarditis
What is treatment?
Amoxicillin 2g 4 hourly
Vancomycin if resistant - enterococci usually are
+
Gentamicin 1mg/kg BD
Swap amoxicillin for vancomycin if penicillin allergic
Coxiella burnetti is rare cause of IE
What are treatment options?
Treatment required for approx 3 years, depending on antibody response
Doxycyline + hydroxychloroquine
Doxycycline + ciprofloxacin
Proven candida endocarditis.
What are treatment options?
Caspofungin
or
Ambisome (amphotericin B
+
Flucytosine
Proven aspergillus endocarditis
What are treatment options?
Voriconazole (monitor levels)
or
Ambisome (amphotericin B
+
Flucytosine