Day #43 - Endocarditis

Today we discussed a great case of subacute bacterial endocarditis which presented as renal failure, uremia, and life threatening hyperkalemia. We discussed the approaches to altered level of consciousness and hyperkalemia. We also briefly discussed the approach to renal failure.

I wanted to touch upon the diagnosis of endocarditis. Endocarditis is a clinical and microbiological diagnosis which is established using epidemiologic criteria. The criteria are called the Modified Duke Criteria. They include:

Major Criteria

Microbiologic:
Positive blood cultures (>=2) with an organism that classically causes endocarditis (viridans group streptococci, staphylococcus aureus, enterococcus, HACEK organisms)
OR
Persistantly positive (>=3 or >=2 12h apart) for another organism

Echocardiologic:
Vegetation on valve not otherwise explainable or dehiscence of mechanical valve or abscess

OR

Clinical: *NEW* (not worsening) regurgitant murmur

Minor Criteria

• Predisposition -- known pre-existing valvular disease or IVDU
• Fever
• Evidence of vascular phenomenon -- septic emboli, mycotic aneurysm, Janeway lesions,
• Immunologic: glomerulonephritis (like this case), positive RF, roth spots, Osler nodes,
• Microbiologic: Blood culture not meeting major
• Echocardiographic not meeting major

Diagnosis: 2 Major, or 1 major 3 minor, or 5 minor

The ACC has updated guidelines on the management of valvular heart disease including endocarditis and endocarditis prophylaxis. These address the diagnostic algorithm and treatment in more detail.