Effect of Preoperative Antibiotic Prophylaxis on Surgical Site Infections Complicating Cardiac Surgery

Abstract

Objective.To evaluate the effect of an optimized policy for antibiotic prophylaxis on surgical site infection (SSI) rates in cardiac surgery.Design.Prospective cohort study.Setting.Tertiary medical center in Israel.Methods.SSIs were recorded during a 10-year study period and ascertained through routine surveillance using the National Healthcare Safety Network (NHSN) methodology. Multivariable analyses were conducted to determine which significant covariates, including the administration of preoperative prophylaxis, affected these outcomes.Results.A total of 2,637 of 3,170 evaluated patients were included, and the overall SSI rate was 8.4%. A greater than 50% reduction in SSI rates was observed in the last 4 years of the study. Overall and site-specific infection rates were similar for patients receiving cefazolin or vancomycin. SSIs developed in 206 (8.1%) of the 2,536 patients who received preoperative prophylaxis (within 2 hours of the first incision) compared with 14 (13.9%) of 101 patients who received antibiotic prophylaxis at a different time (P= .04; odds ratio [OR], 1.8; 95% confidence interval [CI], 1.0–3.3). After accounting for covariates, preoperative hospital stay (5 days or more), an NHSN risk category (2 or 3), age (60 years or more), surgeon's role, and the period of measurement were significantly associated with SSIs. Emergency surgery, age, surgeon's role, and nonpreoperative prophylaxis were found to be independent predictors of superficial SSI.Conclusions.We observed a progressive and significant decrease in SSI rates after the implementation of an infection control program that included an optimized policy of preoperative prophylaxis in cardiac surgery.