chapter  11
12 Pages

Septicemia and Cardiopathies Endocarditis

Endocarditis contributes the most unfortunate false negatives in the hospital laboratory. In subacute bacterial endocarditis (SBE), routine cultures often fail . This was true before antibiotic therapy, even with the best media and arterial tested blood. Currently there has been a rise in culture-negative endocarditis cases.3S Recent figures state the cases from which no organism is recovered may reach 40%. 1 0 In culture-negative SBE cascs , the diagnosis is delayed and "calculated guess" therapy often fails . When an appropriate antibiotic is found, complications may have already occurred. Culture­ negative patients have longer illnesses, more frequent anemia, and more embolic phenomena than culture-positive patients . I S As is well known, without specific antimicrobial therapy, SBE is invari­ ably fatal .