1243. Continuous vs. Intermittent Intraoperative Infusion of Cefazolin on Surgical Site Infections (SSIs) and Acute Kidney Injury in Patients Undergoing Cardiac Procedures

Abstract

Background. Continuous infusion cefazolin (CI) has been investigated as a means to optimize antibiotic exposure for prophylaxis against SSI, notably in patients undergoing cardiac procedures involving cardiac bypass (CPB). However, data are limited on its impact on late SSIs and adverse events. In 6/16, the Duke University Hospital (DUH) Antimicrobial Stewardship Team implemented a program to promote CI. We compared the incidence of culture-confirmed SSIs through postoperative day 90 (POD90) between patients receiving either intermittent infusion cefazolin (INT) or CI intraoperatively. We also compared the rate of acute kidney injury (AKI) between groups. Methods. This retrospective quasi-experimental design included adult and pediatric patients undergoing cardiac surgery at DUH between March 2014 and August 2018 and receiving intraoperative cefazolin (alone or in combination with other antibiotics). Patients were categorized as CI (having received at least 1 intraoperative CI infusion) or INT. Culture-confirmed SSIs utilizing NHSN definitions were recorded and a relative risk (RR) determined. AKI was defined as a ≥0.3 mg/dL rise in serum creatinine within 2 days postoperatively. Results. A total of 2,172 unique surgical procedures (from 2,143 unique patients) were included. Comparisons of groups are summarized in Table 1. Rates of SSIs were 1.1% and 1.6% in the CI and INT groups, respectively (RR [95% confidence interval] for CI 0.73, [0.35, 1.52]). AKI was reported in 12.9% and 17.4% of patients, respectively. Conclusion. We were unable to detect a difference in late SSIs between intraoperative CI and INT cefazolin. Differences observed between AKI between groups requires further investigation, but likely impacted by confounders, including pre-existing renal dysfunction.