Prevalence, Diagnosis, and Microbiology of Ventilator-Associated Pneumonia in Traumatically Injured Patients

Background: Hospital-acquired infections (HAIs) are important risk factors for mortality in trauma patients and are increasingly under scrutiny as markers of healthcare quality. We sought to define the effect of trauma on the prevalence, diagnosis, microbiology, and outcomes of ventilator-associated pneumonia (VAP). Patients and Methods: We performed retrospective national case-control and single-center cohort studies. Injured and non-injured patients from a representative cohort of inpatient hospital visits in the United States from 2010 to 2014 were case-matched, and the prevalence and outcomes of patients with VAP were compared. Patients with a diagnosis of VAP at our institution from 2002 to 2015 were then identified. We compared the effect of trauma on the prevalence, demographics, microbiologic testing, and recovered microorganisms of patients. Results: Overall, 1.7 million trauma visits were identified in the 2010-2014 National Inpatient Sample. In total, 94% of these visits were case-matched with non-injured controls. Trauma visits had a three-fold increased prevalence of a diagnosis of VAP. Cases of VAP (n = 635) were then extracted from our institutional database. We found an increased prevalence of VAP in injured inpatients. Microbiologic cultures were more frequently assessed in injured patients. Injury was associated with an increased frequency of gram-positive VAP and a decreased frequency of gram-negative pneumonia. Discussion: Injured inpatients are three-fold more likely to receive a diagnosis of VAP as compared with uninjured inpatient controls and are more likely to have a microbiologic diagnosis.