Empiric treatment with clindamycin and gentamicin of suspected sepsis due to anaerobic and aerobic bacteria.

Clindamycin and gentamicin were used in combination to treat 107 patients empirically for suspected aerobic-anaerobic sepsis. All patients were seriously ill and required initiation of treatment before results of cultures could be obtained. Infections included intraabdominal sepsis, hospital-acquired aspiration pneumonia, and soft tissue infections. Exudate cultured from 65 patients showed that the prediction of a mixed aerobic-anaerobic flora was correct in 46 patients (71%). Isolates from exudate included Escherichia coli, Bacteroides fragilis, clostridia, peptostreptococci, Proteus species, Klebsiella species, and Staphylococcus aureus. In 29 patients with bacteremia, the most frequent blood culture isolate was B. fragilis. Analysis of response to treatment showed that 92 patients were cured, five could not be evaluated adequately, and 10 failed to respond to therapy. Therapeutic failure primarily resulted from overwhelming sepsis, despite susceptibility of the pathogens to prescribed antibiotics.