Randomized, multicenter trial of antibiotic prophylaxis in elective colorectal surgery - Single dose vs 3 doses of a second-generation cephalosporin without metronidazole and oral antibiotics

Hypothesis: Use of prophylactic antibiotics in elective colorectal surgery is essential. Although single-dose prophylactic antibiotics are recommended, the efficacy of single-dose cephalosporin without metronidazole and oral antibiotics is not fully proven. We conducted a multicenter, randomized trial of a single dose vs 3 doses of the second-generation cephalosporin cefmetazole. Design: A prospective, randomized, multicenter trial in patients undergoing elective colorectal surgery. Setting: Seven major hospitals in Japan that offer cancer treatment. Patients: Patients with colorectal cancer treated from May 6, 2004, to April 25, 2005. Interventions: Patients were randomized to 1 of 2 groups: a single-dose group given a single dose of cefmetazole just before skin incision and a 3-dose group given 2 additional doses of cefmetazole every 8 hours after the first dose just before skin incision. Main Outcome Measures: Incidences of incisional surgical site infection (SSI), organ or space SSI, and all other infectious complications within 30 days after surgery. Results: A total of 384 patients were enrolled. Seven patients were excluded because of additional surgery or the inability to tolerate mechanical preparation. The incidence of incisional SSI was higher in the single-dose group (27/190 or 14.2%) than in the 3-dose group (8/187 or 4.3%) (P = .009). Incidences of organ or space SSI and other postoperative infectious diseases did not differ significantly between the 2 groups. In multivariate analysis, antibiotic dose was the only significant factor related to the incidence of incisional SSI. Conclusion: Three-dose cefmetazole administration is significantly more effective for prevention of incisional SSI than single-dose antibiotic administration. Trial Registration: clinicaltrials.gov Identifier: NCT00292708.