Ventilator-associated pneumonia is an important risk factor for mortality after major cardiac surgery

Abstract

Purpose: Ventilator-associated pneumonia (VAP) is the main infectious complication in cardiac surgery patients and is associated with an important increase in morbidity and mortality. The aim of our study was to analyze the impact of VAP on mortality excluding other comorbidities and to study its etiology and the risk factors for its development.

Materials and methods: This prospective cohort study included 1610 postoperative cardiac surgery patients' status post cardiopulmonary bypass (CPB) between July 2004 and January 2008. The primary outcome measures were the development of VAP and in-hospital mortality.

Results: Ventilator-associated pneumonia was observed in 124 patients (7.7%). Patients with VAP had a longer length of hospitalization (40.7 ± 35.1 vs 16.1 ± 30.1 days, P < .0001) and greater in-hospital mortality (49.2% [61/124] vs 2.0% [30/1486], P = .0001) in comparison with patients without VAP. After performing the Cox multivariant analysis adjustment, VAP was identified as the most important independent mortality risk factor (adjusted hazard ratio [HR], 8.53; 95% confidence interval, 4.21-17.30; P = .0001). Other independent risk factors of in-hospital mortality were chronic renal failure (HR, 2.56), diabetes mellitus (HR, 1.90), CPB time (HR, 1.51), respiratory failure (HR, 2.13), acute renal failure (HR, 2.39), and mediastinal bleeding of at least 1000 mL (HR, 1.81).

Conclusions: The development of VAP after CPB is the most important independent risk factor for in-hospital mortality. Identification of effective strategies for the prevention of VAP is needed.