Infection after penetrating brain injury-An Eastern Association for the Surgery of Trauma multicenter study oral presentation at the 32nd annual meeting of the Eastern Association for the Surgery of Trauma, January 15-19, 2019, in Austin, Texas.

BACKGROUND: Fatality rates following penetrating traumatic brain injury (pTBI) are extremely high and survivors are often left with significant disability. Infection following pTBI is associated with worse morbidity. The modern rates of central nervous system infections (INF) in civilian survivors are unknown. This study sought to determine the rate of and risk factors for INF following pTBI and to determine the impact of antibiotic prophylaxis.

METHODS: Seventeen institutions submitted adult patients with pTBI and survival of more than 72 hours from 2006 to 2016. Patients were stratified by the presence or absence of infection and the use or omission of prophylactic antibiotics. Study was powered at 85% to detect a difference in infection rate of 5%. Primary endpoint was the impact of prophylactic antibiotics on INF. Mantel-Haenszel χ and Wilcoxon's rank-sum tests were used to compare categorical and nonparametric variables. Significance greater than p = 0.2 was included in a logistic regression adjusted for center.

RESULTS: Seven hundred sixty-three patients with pTBI were identified over 11 years. 7% (n = 51) of patients developed an INF. Sixty-six percent of INF patients received prophylactic antibiotics. Sixty-two percent of all patients received one dose or greater of prophylactic antibiotics and 50% of patients received extended antibiotics. Degree of dural penetration did not appear to impact the incidence of INF (p = 0.8) nor did trajectory through the oropharynx (p = 0.18). Controlling for other variables, there was no statistically significant difference in INF with the use of prophylactic antibiotics (p = 0.5). Infection was higher in patients with intracerebral pressure monitors (4% vs. 12%; p = <0.001) and in patients with surgical intervention (10% vs. 3%; p < 0.001).

CONCLUSION: There is no reduction in INF with prophylactic antibiotics in pTBI. Surgical intervention and invasive intracerebral pressure monitoring appear to be risk factors for INF regardless of prophylactic use.

LEVEL OF EVIDENCE: Therapeutic, level IV.