Late-onset ventilator-associated pneumonia in nontrauma intensive care unit patients.

Background: Most studies designed to determine the factors associated with the acquisition of late-onset ventilator-associated pneumonia (VAP) were performed in critically ill trauma patients. The impact of enteral nutrition (EN) on the risk of acquiring VAP has been discussed. In this study, we assessed factors associated with late-onset VAP in nontrauma patients and determined whether nutrition provided early was associated with development of late-onset VAP in this population.

Methods: We performed a prospective observational cohort study in a 21-bed polyvalent intensive care unit in a university hospital.

Results: Three hundred sixty-one intubated adult patients with a duration of mechanical ventilation (MV) of 6 days or more were admitted over a 28-mo period. Late-onset VAP was confirmed in 76 patients (21%) by the presence of at least one microorganism at a concentration >or=10(4) colony-forming units/mL on the bronchoalveolar lavage. Gram-negative bacilli represented 75% and Staphylococcus aureus 21% of recovered organisms. Factors independently associated with late-onset VAP by multivariate analysis included a high simplified acute physiology score II score (odds ratio: 1.021; 95% confidence interval [CI]: 1.005-1.038; P = 0.01), development of acute respiratory distress syndrome during the first 5 days of MV (odds ratio: 1.98; 95% CI: 1.05-3.67; P = 0.04), and size of the endotracheal tube >or=7.5 (odds ratio: 2.06; 95% CI: 1.88-3.90; P = 0.03). EN started within 48 h of MV onset was not associated with a higher risk for late-onset VAP.

Conclusion: In our nontrauma patient population, early EN was not associated with development of late-onset VAP. In this population, severity of the disease during the first 5 days of MV seemed to be associated with late-onset VAP. In addition, our results suggest that the risk of late-onset VAP is higher in patients with a tube size >or=7.5 than in patients with a tube size <7.5.