Comparison of Cefazolin/Metronidazole versus Ampicillin-Sulbactam as Preoperative Antibiotics in Colorectal Surgery: Retrospective, Single-Center Cohort Study

Aim The use of prophylactic antibiotics prior to colorectal surgery reduces surgical site infections. Cefazolin and metronidazole is a standard regimen. Ampicillin-sulbactam may be an alternative, but the data are limited. We compared the efficacy of ampicillin-sulbactam with cefazolin and metronidazole as prophylactic antibiotics. Methods Patients who underwent colorectal surgery at Inha University Hospital between 2010 and 2020 were treated prophylactically with cefazolin and metronidazole or ampicillin-sulbactam, and observed for 30 days following surgery. The primary outcome was surgical site infections. Secondary outcomes were deep/organ infections and the need for drainage. Results SSIs occurred in 2.6% (17/646) of the ampicillin-sulbactam group and was not inferior to the occurrence in the cefazolin and metronidazole group (3.8%, 21/556). There was no significant difference between the two groups in the secondary outcomes. Conclusion Compared with the cefazolin and metronidazole combination, the ampicillin-sulbactam group is non-inferior as a preoperative prophylactic antibiotic regimen for colorectal surgery.