Management of intra-abdominal infections. The case for intraoperative cultures and comprehensive broad-spectrum antibiotic coverage. The Canadian Intra-abdominal Infection Study Group
N. V. Christou, P. Turgeon, R. Wassef, O. Rotstein, J. Bohnen and M. Potvin
Department of Surgery, Royal Victoria Hospital, McGill University, Montreal, Quebec.
OBJECTIVE: To test the hypothesis that comprehensive broad-spectrum
empirical antimicrobial therapy is superior to limited-spectrum empirical
antimicrobial therapy in intra-abdominal infections. DESIGN: Prospective,
randomized, double-blinded study. SETTING: University-affiliated hospitals
in Canada. PATIENTS: Two hundred thirteen patients with intra-abdominal
infections and planned operative or percutaneous drainage. INTERVENTION:
Limited-spectrum empirical antimicrobial therapy consisted of cefoxitin
sodium, 2 g, intravenously, every 6 hours (n = 109). Comprehensive
broad-spectrum empirical antimicrobial therapy consisted of a combination
of imipenem and cilastatin sodium, 500 mg, intravenously, every 6 hours (n
= 104). MAIN OUTCOME MEASURES: Failure to cure the intra-abdominal
infection (persistence of infection or death). RESULTS: Of initial
isolates, 98% were sensitive to imipenem plus cilastin sodium compared with
72% for cefoxitin. No difference was found in the failure rate between
treatment groups. Among various reasons for failure (including technical),
12 of 80 patients in the limited-spectrum empirical antimicrobial therapy
group had resistant organisms at a second intervention compared with 1 of
74 in the comprehensive broad-spectrum empirical antimicrobial therapy
group (P < .003, chi 2). One death in the limited-spectrum empirical
antimicrobial therapy group was due to autopsy-proved disseminated
Pseudomonas aeruginosa (blood, peritoneum, lung, and pleural fluid) that
was resistant to cefoxitin, and the other was associated with peritonitis
due to cefoxitin-resistant Enterobacter cloacae. One death in the
comprehensive broad-spectrum empirical antimicrobial therapy group was
associated with peritonitis from Clostridium perfringens that was sensitive
to imipenem plus cilastin sodium, and the other was associated with
peritonitis from Pseudomonas aeruginosa that was resistant to imipenem plus
cilastin sodium. CONCLUSION: Treatment failure of intra-abdominal infection
may be due, in part, to the presence of resistant pathogens at the site of
infection. Therefore, routine culture of these sites seems worthwhile and
empirical therapy should be as comprehensive as possible and should cover
all potential pathogens.
