Infective Endocarditis: Prognosis and Management

Key points

• Mortality by organism: staphylococci 30% · bowel organisms 15% · streptococci 5% — streptococcal (e.g. viridans) infection carries a good prognosis.
• Poor prognostic factors: Staph aureus infection · prosthetic valve (especially 'early', acquired during surgery) · culture-negative endocarditis · low complement levels.
• BNF initial blind therapy: native valve → amoxicillin (consider adding low-dose gentamicin); penicillin allergy/MRSA/severe sepsis → vancomycin + low-dose gentamicin; prosthetic valve → vancomycin + rifampicin + low-dose gentamicin.
• Staphylococci: native valve → flucloxacillin; prosthetic valve → flucloxacillin + rifampicin + low-dose gentamicin (vancomycin regimens if penicillin-allergic/MRSA); fully-sensitive streptococci (e.g. viridans) → benzylpenicillin alone; less sensitive streptococci → benzylpenicillin + low-dose gentamicin.
• Indications for surgery: severe valvular incompetence · aortic abscess (often a lengthening PR interval) · antibiotic-resistant/fungal infection · cardiac failure refractory to medical treatment · recurrent emboli after antibiotics; coagulase-negative staphylococci (Staph epidermidis) dominate the first 2 months post valve surgery.

Decision points in this pathway

• Initial blind therapy required (organism unknown)?
• Endocarditis caused by staphylococci?

The full step-by-step algorithm, including what to do at each branch, opens in the app for approved members.