Impact of antibiotic prophylaxis on the occurrence of early-onset ventilator-associated pneumonia in trauma patients (antiVAP): a propensity score–weighted, retrospective cohort study

Short-course antibiotic prophylaxis has been associated with a reduced risk of early-onset ventilator-associated pneumonia (VAP) in selected populations, particularly patients with acute brain injury. However, its role in severely injured trauma patients remains controversial. This multicentre, retrospective cohort study, conducted in 15 French trauma centres, included severely injured adults who required mechanical ventilation initiated within 24 h of admission and continued for at least 48 h. Propensity score–based analyses assessed the association between early antibiotic prophylaxis (initiated within the first 24 h of management and continued for up to 72 h) and patient outcomes. The primary outcome was early-onset VAP; secondary outcomes included late-onset VAP, extrapulmonary infections, duration of mechanical ventilation, ICU and hospital length of stay, and 30-day mortality. A total of 1,321 trauma patients were included. Antibiotic prophylaxis was administered to 746 patients (56%), with amoxicillin–clavulanic acid used in more than 90% of cases. Early-onset VAP occurred in 240 of 746 patients (32%) who received antibiotic prophylaxis and in 195 of 575 (34%) who did not. After inverse probability of treatment weighting (IPTW), antibiotic prophylaxis was not associated with early-onset VAP (weighted odds ratio [wOR] 0.87, 95% CI 0.66–1.22; p = 0.48). A cause-specific Cox model accounting for the competing risk of death before day 7 yielded similar results (cause-specific hazard ratio [csHR] 0.87, 95% CI 0.71–1.07; p = 0.19). Antibiotic prophylaxis was not associated with improve of secondary outcomes. Routine antibiotic prophylaxis in severely injured trauma patients was not associated with a reduced risk of early-onset VAP. Gov ID NCT07059039 – Registration date: July, 10th 2025