Endocarditis

[Circulation 2015; 132:1487-1515]

Diagnosis includes:

• multiple positive blood cultures

• new murmur

• definite emboli

• vegetations on echocardiogram.

- For more specific diagnostic criteria, refer to Modified Duke Criteria www.circulationaha.org (Circulation 2015; 132:1487-1515).

Blood cultures:

• NB: In patients with underlying heart disease and fever, collect two blood cultures before starting antibiotic therapy. In patients who are stable (no heart failure) with subacute presentation, wait for results of blood cultures before starting antibiotic therapy.

• draw maximum 2 sets/day

• consult microbiology laboratory if unusual/fastidious (Bartonella, Chlamydia, Coxiella, Brucella, Legionella, Tropheryma whippleii) organism suspected

• repeat blood cultures every 48h until clearance of bacteremia to guide duration of therapy. Duration of therapy should start from date of first negative blood culture.

- For specific organism recommendations or blood culture negative endocarditis, see Treatment of Culture-proven Endocarditis & Blood Culture Negative Endocarditis (BCNE), respectively in Recommended Therapy of Culture-directed Infections in Adult Patients. Use pediatric doses (Table A).

Vancomycin

• Vancomycin is less rapidly bactericidal than ß-lactams, so should only be used when β-lactams contraindicated (due to severe allergy or resistance). Longer duration of therapy may be required.

• Desired vancomycin trough is 10-20mg/L. Monitor renal function closely.