Association Between a Silver-Coated Endotracheal Tube and Reduced Mortality in Patients With Ventilator-Associated Pneumonia

Background: A silver-coated endotracheal tube (ETT) reduced the incidence of ventilator-associated pneumonia (VAP) compared with an uncoated ETT in the North American Silver-Coated Endotracheal Tube (NASCENT) study. Methods: To evaluate the effect of an ETT and risk factors on mortality, we performed a retrospective cohort analysis in patients who developed VAP in the NASCENT study. We determined causes of death and VAP due to potentially multidrug-resistant bacteria (eg, Pseudomonas, Acinetobacter) and performed stepwise multivariate logistic regression with the following predefined variables: treatment group, Acute Physiology and Chronic Health Evaluation (APACHE) 11 score, continuous sedation, coma, COPD, emergency surgery/trauma, immunodeficiency, potentially multidrug-resistant bacteria, and inappropriate initial antibiotics. Results: The silver-coated ETT was associated with reduced mortality in patients with VAP (silver vs control, 5/37 [14%] vs 20/56 [36%], P = .03), but not in those without VAP (228/729 [31%] vs 178/687 [26%], P = .03). The only between-group difference in leading causes of death was respiratory failure (silver vs control, 45/233 [19%] vs 22/198 [11%], P = .02). Of the VAP-related deaths, one in the silver group was caused by Acinetobacter sepsis. In the control group, six deaths were caused by sepsis and three by pneumonia; six of nine pathogens were potentially multidrug resistant. In multivariate analysis, the treatment group was a predictor of mortality (odds ratio, silver vs control, 0.28; 95% CI, 0.09-0.89; P = .03). APACHE II >= 20 and inappropriate antibiotics also remained in the model (P < .1). Conclusions: These findings suggest that a silver-coated ETT was associated with reduced mortality in patients who developed VAP in the NASCENT study. Studies are needed to confirm these exploratory findings. CHEST 2010; 137(5):1015-1021