Relevance and Utility of Peritoneal Cultures in Patients with Peritonitis

Abstract

Background: The pathogenic organisms responsible for the manifestations of secondary peritonitis have been well characterized through almost 30 years of experimental and clinical studies. Enteric gram-negative organisms and anaerobes predominate, with Escherichia coli and Bacteroides fragilis, respectively, being the most frequent isolates. This flora is remarkably consistent across patients and institutions. As a result of this consistency and the availability of well-established effective empiric antimicrobial regimens, many surgeons believe that cultures of peritoneal exudates in patients with peritonitis offer no useful information and no clinical benefit. Methods: Review of pertinent antibiotic and management trials in the management of intraabdominal infection. Results: There is increasing evidence that identification of organisms resistant to the chosen empiric antibiotic regimen portends a higher likelihood of failure. What is not clear is whether postoperative changes in the regimen in accordance with sensitivity patterns of the isolates offers any clinical advantage. In most circumstances, the data provided allow for simplification of the antibiotic regimen. Conclusion: The potential for reducing antibiotic exposure and the value of information derived from surveillance of microbial sensitivity patterns support the routine performance of peritoneal cultures.