2026 Eastern States Conference

Authors: Jovina Fager, PharmD; Alex Matika, PharmD, BCIDP; Lauren Allen, PharmD, BCIDP; Julia Bold, PharmD; Esrat Jahan, PharmD; Justin Miller, PharmD

Learning objective: Evaluate the impact of preoperative antibiotic timing on odds of surgical site infection (SSI).

Background: The ideal timing of preoperative antibiotic administration in relation to incision time remains unclear. This study aims to evaluate the optimal timing of preoperative antibiotic administration to mitigate the odds of SSIs.

Methods: This study was a retrospective, case-control trial evaluating 993 adult patients admitted to St. Luke’s University Health Network for a surgical procedure from January 2022 to December 2024. Patients were included at a 1:4 case-to-control, with cases defined as patients who developed a SSI, and controls defined as patients without subsequent SSI. Patients were excluded if they did not receive preoperative antibiotics, received preoperative antibiotics > 120 minutes prior to incision, underwent more than one procedure during index hospitalization, or had a preexisting infection at time and anatomical site of index procedure. The primary outcome was SSI odds by preoperative antibiotic administration time. Secondary outcomes included admission, hospital length of stay, and readmission for SSI management; and mortality at 30 and 90 days post-operation. SSIs were categorized using National Healthcare Safety Network definitions. The primary outcome was assessed using logistic regression.

Results: Cefazolin was the most frequent preoperative antibiotic administered (863 of 993 cases). This study demonstrated that cefazolin administration beyond 45 minutes prior to incision was associated with increased odds of SSI compared with administration at 15-45 minutes (OR 3.30, 95% CI 1.30-8.42; p = 0.012). In the subgroup analysis, clindamycin was associated with increased odds of SSI compared with cefazolin (OR 2.07, 95% CI 1.15-3.73; p = 0.015). 

Conclusion: Cefazolin should be administered within 45 minutes of procedure initiation to best mitigate the odds of SSIs. Cefazolin was associated with a decreased odds of SSIs compared with clindamycin, supporting its use as the preoperative antibiotic of choice.

Self-assessment question: Based on the results of this trial, in what time frame should cefazolin be administered preoperatively to best mitigate the odds of SSIs?
A. 0 to 45 minutes
B. 45 to 60 minutes
C. 60 to 120 minutes
D. None of the above