Cefazolin Dose-Response-based Correlation of Weight With Orthopaedic Implant-related Surgical-site Infections.

Abstract

Background: This study aimed to evaluate the association of the initial body weight-stratified cefazolin antimicrobial prophylaxis (AMP) dose and surgical-site infection (SSI) in major orthopedic implant surgery.

Methods: This nationwide, retrospective cohort study used data from the Diagnosis Procedure Combination database. We included patients (age ≥18 years) who underwent major orthopedic implant surgery between July 2010 and March 2022. Patients underwent surgery with an initial cefazolin dose of either 1 g (1 g cefazolin group) or 2 g (2 g cefazolin group). Primary outcome was in-hospital SSI. Restricted cubic spline functions were used to estimate the nonlinear association of body weight-stratified cefazolin dose with the outcome and between cefazolin dose per weight and the outcome.

Results: Among the 408,487 participants, 394,731 and 13,756 were in the 1 g and 2g cefazolin groups, respectively. The 1 g cefazolin group, but not the 2 g cefazolin group, showed a J-shaped relationship between body weight and SSI, which increased continuously beyond 50 kg, in an increased risk of SSI with body weight. A reverse J-shaped relationship was observed between cefazolin dose per weight and SSI, with an increased risk of SSI at <20 mg/kg.

Conclusion: An increased risk of SSI was observed with 1 g cefazolin, but not with 2 g cefazolin, as an initial AMP with higher body weight among adults weighing >50 kg.