VENTILATOR-ASSOCIATED PNEUMONIA - A MULTIVARIATE-ANALYSIS

Objectives.-To identify factors associated with the development of ventilator-associated pneumonia (VAP) and to examine the incidence of VAP in different intensive care unit (ICU) populations. Design.-An inception cohort study. Setting.-Barnes Hospital, St Louis, Mo, an academic tertiary care center. Patients or Other Participants.-A total of 277 consecutive patients required mechanical ventilation for longer than 24 hours from a medical ICU (75 patients), surgical ICU (100 patients), or cardiothoracic ICU (102 patients). Interventions.-Prospective patient surveillance and data collection. Main Outcome Measures.-Ventilator-associated pneumonia and ICU mortality. Results.-Ventilator-associated pneumonia occurred in 43 patients (15.5%). Stepwise logistic regression analysis identified four factors to be independently associated with VAP (P<.05): an organ system failure index of 3 or greater (adjusted odds ratio [AOR]=10.2; 95% confidence interval [CI], 4.5 to 23; P<.001); patient age of 60 years or older (AOR=5.1; 95% CI, 1.9 to 14.1; P=.002); prior administration of antibiotics (AOR=3.1; 95% CI, 1.4 to 6.9; P=.004); and supine head positioning during the first 24 hours of mechanical ventilation (AOR=2.9; 95% Cl, 1.3 to 6.8; P=.013). Ventilator-associated pneumonia occurred more often in cardiothoracic patients (21.6%) compared with medical patients (9.3%) (P=.03). Patients with VAP also had a higher mortality (37.2%) than those without; VAP (8.5%) (P<.001). An organ system failure index of 3 or greater (AOR=16.1; 95% CI, 6.1 to 42; P<.001), a premorbid lifestyle score of 2 or greater (AOR=3.1; 95% CI, 1.3 to 7.3; P=.012), and supine head positioning during the first 24 hours of mechanical ventilation (AOR=3.1; 95% CI, 1.2 to 7.8; P=.016) were independently associated with mortality. Conclusions.-These data suggest potential interventions that might affect the incidence of VAP or outcome associated with VAP. Additionally, they indicate that different ICU populations may have different incidences of VAP.