Endocarditis

WARNING SIGNS OF INFECTIVE ENDOCARDITIS

• Unexplained fever and cardiac murmur

• Febrile illness after instrumentation or minor and major surgical procedures

Only 50% have previously known heart disease. Consider the possibility in IV drug users.

Main test is blood culture: at least 3 sets of samples within first hour.

Echocardiography (TOE more sensitive than TTE).

ANTIMICROBIAL TREATMENT

There are two important principles of management:

• Treatment must be given IV for at least 2 wks.

• Treatment is prolonged—usually 4–6 wks.

Consultation with an infectious disease physician or clinical microbiologist should be sought. Once cultures have been taken prompt empirical antimicrobial treatment should be commenced, esp. in fulminating infection suspected to be endocarditis. Benzylpenicillin + gentamicin + di(flu)cloxacillin are recommended. Vancomycin needs to be considered if hospital acquired, MRSA suspected or prosthetic cardiac valve.

Prevention of endocarditis Value of prophylaxis unclear.

Low-risk patients (no prosthetic valves or previous attack of endocarditis): prophylaxis not recommended

High-risk patients (prosthetic values, all acquired valvular disease, past history, most congenital heart disease, mitral valve prolapse with regurgitation) having invasive dental procedures, oral or upper respiratory tract surgery, GIT or genitourinary surgery (consult an infectious disease physician):

• phenoxymethylpenicillin 2 g (child 40 mg/kg up to 2 g) orally, 1 hr before procedure

• amoxicillin 2 g (50 mg/kg up to adult dose) orally, 1 h beforehand (if not on long-term penicillin) or

• (amoxi) ampicillin 2 g (50 mg/kg up to adult dose) IV just before procedure commences or IM 30 mins before; if having a general anaesthetic (depending on circumstances)

• if hypersensitive to penicillin: clindamycin or cephalexin