Endocarditis

Question 1

Warning signs of infective endocarditis

Answer 1

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)

Question 2

Classic tetrad:

Answer 2

signs of infection + heart disease + embolism & immunological phenomenon, e.g. arthritis.

Question 3

Antimicrobial treatment

Answer 3

There are two important principles of management:

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

Question 4

Prevention of endocarditis

Answer 4

Value of prophylaxis unclear.

1. Low-risk pts (no prosthetic valves or previous attack of endocarditis):

• prophylaxis not recommended

2. High-risk pts:

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

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

(Amoxy) 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 plus (depending on circumstances)