Diffuse peritonitis treated with tobramycin and clindamycin. Bacteria in relation to preoperative duration of illness.

Twenty consecutive patients, mean age 71 years, with a peroperative diagnosis of diffuse peritonitis were treated with clindamycin and tobramycin. The aim of this open prospective study was to correlate bacterial findings at operation to the duration of illness. The effectiveness of the treatment was also evaluated. The number of aerobic strains from peritoneal cultures outnumbered anaerobes when duration of illness was less than three days, while the opposite was evident when duration was longer. All isolates were fully susceptible to the antibiotic combination except for four anaerobic strains with MIC greater than 1 mg/l for clindamycin. The response to treatment was good in 18 patients, fair in one and poor in one.