Association Between Timing of Antibiotics and Deep Surgical Site Infection in Gustilo-Anderson Type III Open Tibia Fractures.

Abstract

To determine the association between the timing of antibiotic delivery in the emergency department (ED) and deep surgical site infection in Gustilo-Anderson (GA) type III open tibia fractures. Design: Retrospective cohort study. Single Level I Trauma Center. Patients aged ≥18 years with a Gustilo-Anderson (GA) type III open tibia fracture (OTA/AO 41, 42, or 43) from 2016 to 2021 were included. The outcome was deep surgical site infection requiring irrigation and debridement. The effect of time of delivery of antibiotics was compared in 3 analyses: as a continuous variable, before vs after 60 minutes, and before vs after 180 minutes. The study analysis accounted for known confounders for infection, including Injury Severity Score (ISS), GA classification, and wound contamination. The study population included 191 patients with a mean age of 44 years (SD: 17) and 153 males. The median time from arrival to the first antibiotic was 44 minutes (IQR: 21-147). The majority of patients (99.0%) received cephazolin as their initial antibiotic. The overall 90-day risk of deep surgical site infection requiring irrigation and debridement was 10.5%. The timing of antibiotic administration as a continuous variable was not associated with infection (aOR: 1.00, 95% CI: 0.99-1.00, P = 0.39). Similarly, time to antibiotic administration was not associated with infection at thresholds of 1 hour (aOR: 1.02, 95% CI: 0.39-2.68, P = 0.96) or 3 hours (aOR: 1.08, 95% CI: 0.35-3.37, P = 0.89) in separate models. Early antibiotic administration was not associated with a reduced risk of deep surgical site infection in GA type III tibia fractures. These results suggest that the acute timing of antibiotics may not be as impactful to patients' risk of infection as once considered. Therapeutic, Level III.