Single-dose antibiotic prophylaxis is effective enough in colorectal surgery.

Background: The aim of this study was to investigate the hypothesis that prevention of surgical site infection (SSI) is equally effective when patients receive single-dose (SD) or three-dose antibiotic prophylaxis with second-generation cephalosporin and metronidazole in elective colorectal surgery.

Methods: Ninety-three patients were enrolled from May 2009 to November 2010. The SD group received only one preoperative prophylactic intravenous dose and the three-dose or multiple-dose (MD) group received one preoperative prophylactic and two additional post-operative doses of second-generation cephalosporin and metronidazole. The incidence of infectious complications (SSI of the incision site and organ/space) was compared in the two groups.

Results: The overall post-operative infection rate did not differ between the two groups (16.7% in the SD versus 13.3% in the MD, P = 0.653). The incidence of SSI of the incision site and organ/space also did not differ between the groups (6.3% (3/48) versus 4.4% (2/45), P = 0.700; 4.2% versus 6.7%, P = 0.593, respectively). The number of antibiotics administered was not an independent risk factor for SSIs in multivariable analysis.

Conclusions: SD antibiotic prophylaxis with second-generation cephalosporin and metronidazole is equivalent to a three-dose prophylaxis for preventing SSI in elective colorectal surgery. But further study would be needed to clarify this because of the small number of participants.