Prophylactic cefazolin concentrations in lumbar spine surgery: a comparison of tissue and plasma cefazolin concentrations to body composition

Abstract

Surgical site infections (SSI) are a leading complication in orthopaedic surgery. Weight- or BMI-based prophylactic antibiotics have been proven to reduce SSI. In orthopaedic surgery cefazolin is commonly used as the prophylactic antibiotic of choice however the scientific basis for the weight-based regimen often used is weak. The aim of this research was to report the relationship between the plasma and surgical site concentration of prophylactic cefazolin with measures of body composition. Lean mass weight was demonstrated to be the strongest predictor for plasma cefazolin concentration. Weight was the other measurement of body composition to be found significant. Muscle tissue cefazolin concentrations correlated with plasma concentrations taken at the same time point. No significant correlation between measurements of body composition and muscle tissue cefazolin concentrations were found. All plasma and tissue cefazolin concentrations were found to achieve the minimal inhibitory concentration required to act as a successful prophylactic agent in lumbar spine surgery. This is the first study to demonstrate a linkage between lean body mass weight and plasma cefazolin concentration. Further research is warranted exploring cefazolin concentrations with regards to other tissue of the lumbar spine as well as extreme BMIs in lumbar spine surgery.