Ventilator-Associated Pneumonia, Like Real Estate: Location Really Matters

Abstract

Previous work has demonstrated an increased risk of ventilator-associated pneumonia (VAP) in trauma patients after prehospital (field) intubation as compared with emergency department (ED) intubations. However, this population was not compared with patients intubated as inpatients, making data interpretation difficult. We sought to further examine predictors for the development of VAP after trauma. A 10-year retrospective review of all patients mechanically ventilated greater than 24 hours after injury was performed. In all, 1,628 patients were identified, of which 1,213 (75%) were intubated as inpatients and 415 were emergently intubated (353 ED, 62 field). Overall, those intubated emergently were younger (p = 0.03) and less injured as seen by higher Glasgow Coma Scale scores (p = 0.0002), lower Injury Severity Scores (p = 0.01) and higher Revised Trauma Scores (p < 0.0001). Despite a lower injury severity, those patients emergently intubated were more likely to develop pneumonia as 22% of ED intubations and 15% of field intubations developed pneumonia, as compared with the inpatient rate of 6.5%. Pneumonia after field intubation was more likely to be community-acquired (p < 0.0001) with a significantly lower percentage of infecting enteric gram-negative rods (p < 0.0001) as compared with the inpatient and ED groups. Forward logistic regression analysis (with VAP = 1) identified inpatient intubation as protective against VAP (odds ratio 0.28, 95% CI = 0.2-0.4). Backwards logistic regression analysis further identified both field airway (odds ratio 2.29, 95% CI = 1.1-4.9) and ED airway (odds ratio 3.61, 95% CI = 2.5-5.2) as predictive of VAP. Compared with a population of trauma patients as inpatients, and excluding those patients mechanically ventilated less than 24 hours, patients intubated in the ED or field have a higher incidence of pneumonia, despite equivalent or lower injury severity.