Antibiotic therapy of endometritis following cesarean section. Treatment successes and failures.

A prospective clinical and microbiologic study was carried out on 413 indigent patients undergoing cesarean section. Operative site infection developed in 160 (38.5%). Initial treatment with penicillin and kanamycin was successful in 125 of these 160 infections (78%). Thirty-five patients (22%) failed to respond to penicillin and kanamycin and were treated with clindamycin or chloramphenicol. Twenty-eight of the 35 responded promptly to the additional antibiotic therapy. The remaining 7 patients (4%) had either abscesses, hematomas, or presumed septic pelvic thrombophlebitis. Among patients with anaerobic cultures, B fragilis was isolated with 12% with a good response to penicillin-kanamycin, but from 53% with a poor response to penicillin-kanamycin and with a good response to clindamycin or chloramphenicol. Similar critical evaluations of other antibiotic regimens are needed.