Acute appendicitis and the use of intraperitoneal cultures

We reviewed the charts of 200 patients with a preoperative diagnosis of acute appendicitis (AA) to evaluate the influence and use of intraoperative culture results on patient management and antibiotic selection. Cultures were obtained in 66 percent of patients; 16 percent of the cultures in patients with AA yielded positive results versus 88 percent of cultures in patients with perforated or gangrenous appendicitis (complicated appendicitis [CA]) and in nine patients, positive cultures were used to adjust antibiotic therapy. Patients with CA who had antibiotic changes based on culture results had a complication rate of 25 percent versus a 29 percent rate for this group as a whole. We conclude that intraoperative cultures in patients with AA are rarely positive and do not influence antibiotic therapy or patient management. In CA, antibiotic changes based on culture results do not seem to alter patient outcome. Surgeons tend to rely on the proved efficacy of empiric antibiotic therapy and other basic surgical principles to afford the best outcome for their patients. The routine practice of obtaining peritoneal cultures in patients operated upon for AA and CA should be abandoned.