Surveillance of Ventilator-associated Pneumonia in a Neonatal Intensive Care Unit: Characteristics, Risk Factors, and Outcome

Background: This study determined the incidence, characteristics, risk factors, and outcomes of ventilator-associated pneumonia (VAP) in newborns hospitalized in a Neonatal Intensive Care Unit (NICU) in Tehran, Iran. Methods: A prospective cohort study was carried out in the NICU of Mandieh Hospital over a period of one year, from December 2008 to November 2009, on all neonates mechanically ventilated for more than 48 hours. VAP was diagnosed in accordance with the CDC definition of nosocomial pneumonias for patients younger than 12 months. Risk factors relevant to the development of VAP were studied. Multiple logistic and Cox regression analysis were performed to determine independent predictors for VAP and survival rate, respectively. Results: There were 81 neonates enrolled. VAP occurred in 14(17.3%), at a rate of 11.6/1000 days on the ventilator. Gram negative bacteria were the predominant etiologic agents. The most common bacterial isolates from the endotracheal aspirate were E.coli (21.4%), Klebsiella (21.4%), and Pseudomonas (14.1%). The only VAP predictor was sputum [odds ratio (OR)=5.11, P=0.02]. Mortality rate for VAP was 2/14(14.3%). Duration of mechanical ventilation [hazard ratio (HR)=0.96, P=0.01], birth weight (HR=0.81, P<0.001), and purulent tracheal aspirate (HR=0.25, P<0.006) were independent predictors of overall survival. Conclusion: VAP occurs at a significant rate in mechanically ventilated newborns. Additional studies are needed to accurately determine the incidence and risk factors in order to develop effective preventive and therapeutic protocols.