Gangrenous and perforated appendicitis with peritonitis: treatment and bacteriology

A comparison of single-agent antimicrobial therapy in the treatment of patients with perforated or gangrenous appendicitis and peritonitis was performed in a double-blind, randomized, prospective trial. Pathologic documentation of advanced appendicitis and positive intraoperative specimen cultures were required for inclusion in the study. Ceftizoxime (2 gm every 12 hours) and cefoxitin (2 gm every six hours) were compared. There were no significant differences between the treatment groups. Ninety-seven percent of patients treated with ceftizoxime and 89% of those treated with cefoxitin were cured or improved; there was no mortality in either group. By the use of optimal sampling, transport, and culture techniques, the number and diversity of bacteria recovered from these patients with advanced appendicitis were found to be much larger than previously suspected. Peritoneal fluid, abscess contents (if present), and appendiceal tissue (obtained so as to exclude the lumen) were cultured from all patients. An average number of 3.1 aerobic or facultative bacteria species and 8.5 anaerobic species were isolated from each specimen. Twenty-eight different genera and more than 55 species were encountered, including a previously undescribed fastidious gram-negative anaerobic bacillus. Bacteroides fragilis group and Escherichia coli were isolated from almost all specimens, and within the B fragilis group, eight species were represented. The recovery of such an unexpectedly large and diverse flora may be the reason for the therapeutic failures in these patients. We conclude that single-agent antimicrobial therapy in patients with advanced appendicitis and peritonitis is both safe and effective, and, with ceftizoxime, can be accomplished by a twice-daily dosing regimen.