Ventilator-associated pneumonia. A multivariate analysis

Abstract

<h3>Objectives.</h3> —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. <h3>Design.</h3> —An inception cohort study. <h3>Setting.</h3> —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). <h3>Interventions.</h3> —Prospective patient surveillance and data collection. <h3>Main Outcome Measures.</h3> —Ventilator-associated pneumonia and ICU mortality. <h3>Results.</h3> —Ventilator-associated pneumonia occurred in 43 patients (15.5%). Stepwise logistic regression analysis identified four factors to be independently associated with VAP (<i>P</i>&lt;.05): an organ system failure index of 3 or greater (adjusted odds ratio [AOR]=10.2; 95% confidence interval [CI], 4.5 to 23;<i>P</i>&lt;.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;<i>P</i>=.004); and supine head positioning during the first 24 hours of mechanical ventilation (AOR=2.9;95%CI,1.3to6.8;<i>P</i>=.013). Ventilator-associated pneumonia occurred more often in cardiothoracic patients (21.6%) compared with medical patients (9.3%) (<i>P</i>=.03). Patients with VAP also had a higher mortality (37.2%) than those without VAP (8.5%) (<i>P</i>&lt;.001 ). An organ system failure index of 3 or greater (AOR=16.1; 95% CI, 6.1 to 42;<i>P</i>&lt;.001), a premorbid lifestyle score of 2orgreater(AOR=3.1;95%CI,1.3to7.3;<i>P</i>=.012), and supine head positioning during the first 24 hours of mechanical ventilation (AOR=3.1; 95% CI, 1.2 to 7.8;<i>P</i>=.016) were independently associated with mortality. <h3>Conclusions.</h3> —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. (<i>JAMA</i>. 1993;270:1965-1970)