1113 Monotherapy Versus Polytherapy in Prophylactic Antibiotic Use in Penetrating Traumatic Brain Injuries: A Single Center Civilian Observational Analysis

INTRODUCTION: Prophylactic antibiotic use remains controversial in the setting of penetrating traumatic brain injuries (pTBIs). Despite no substantive supportive evidence, 2001 guidelines recommend broad-spectrum (BS) antibiotic use for all pTBIs. Here we present an a single center civilian population observational analysis of prophylactic BS therapy vs. monotherapy (MT) for infection prevention in pTBIs from gun shot wounds. METHODS: We conducted a observational analysis of patients suffering pTBI from gunshot wounds at a single Level-1 trauma center from January 2016 to August 2023 that were identified from the local trauma registry. Data were collected from the electronic medical record. We included patients older than 16 years with evidence of dural penetration on CT imaging. We only included patients that survived more than 5 days. An analysis was used to compare the nominal values of infection across treatment groups. RESULTS: 128 pTBIs from January 2016 to August 2023 were identified. 114 undergoing BS treatment and 14 undergoing MT after hospital protocol was changed in January 2023. We found that the rate of wound infections was similar in BS vs MT (4.4% vs 7.1%, p=0.013). S. aureus was the most common pathogen of intracranial wound infections. CONCLUSIONS: In this single-center observational analysis, we show that wound infections are similar with monotherapy prophylaxis compared to broad-spectrum antibiotic use for pTBIs. However, total infections including ventriculitis were higher with MT alone. The majority of patients who developed ventriculitis had intracranial pressure monitors, serving as a secondary source of infection. Further analysis of all infections revealed that trajectory of the balistic may be an important source of treatment selection depending on frontal sinus involvement. Further investigations of antibiotic prophylaxis in pTBIs are indicated.