To explore risk factors and etiology of ventilator-associated pneumonia (VAP) in patients with severe traumatic brain injury (sTBI).

The clinical information and pathogenetic data of 169 patients with sTBI who required mechanical ventilation for more than 48 h after injury and were admitted in Neurosurgery Department of the 901^st Hospital of the Joint Logistics Support Force of PLA form January 2020 to December 2022 were collected. The patients were divided into non VAP group and VAP group based on the presence or absence of VAP, and further divided into early-onset-VAP (EOVAP) group and late-onset-VAP (LOVAP) group based on the time of VAP occurrence. Risk factors and pathogens of VAP were analyzed by multivariate Logistic regression analysis. the pathogenic distribution was recorded and its resistance rate to antibiotics was calculated.

Among the 169 sTBI patients, 84 were VAP patients, with an incidence rate of 49.70%, including 44 cases in the EOVAP group and 40 cases in the LOVAP group. Multivariate Logistic regression analysis showed that age, coma, head injury, chest injury, lung contusion, and ISS score were independent risk factors for VAP, with age, coma, head injury, and ISS score being common independent risk factors for EOVAP and LOVAP. Pathogen detection results showed that the bacteria in EOVAP patients with sTBI were mostly Acinetobacter baumannii, Klebsiella pneumoniae and Staphylococcus aureus, while the pathogens, such as Acinetobacter baumannii, Pseudomonas aeruginosa and Stenotrophomonas maltophil, in LOVAP patients had resistance to multiple antibiotics, especially to carbapenem antibiotics.

The factors that cause VAP in sTBI patients are variant. Age, coma, head injury and ISS are common independent risk factors of EOVAP and LOVAP. The dynamic bacterial profile and bacterial resistance profile during VAP occurrence have certain significance for empirical antibiotic use.