Independent predictors of prolonged mechanical ventilation after coronary artery bypass surgery

OBJECTIVE: To determine independent predictors of prolonged mechanical ventilation in patients undergoing coronary artery bypass graft surgery. METHODS: Data of patients undergoing coronary artery bypass graft surgery were included prospectively from July 2009 to July 2010. All data were input into an electronic database. The resulting cohort included a total of 2952 patients of which 77 remained more than 48 hours on mechanical ventilation. Patients were divided into two groups: 1) a prolonged ventilation group, needing mechanical ventilation for more than 48 hours and 2) not prolonged ventilation group, undergoing a successful extubation within 48 hours. RESULTS: After adjustment for confounding factors a multivariate analysis identified the following factors as independent predictors of prolonged mechanical ventilation: age (OR 1.06 95% CI 1.03 -1.09; P <0.001), chronic renal failure (OR 3.52 95% CI 1.84 - 6.74; P <0.001), chronic obstructive pulmonary disease (OR 2.65 95% CI 1.38 -5.09; P = 0.004), coronary artery bypass graft associated with other procedures (OR 3.33 95 % CI 1.89 - 5.58; P <0.001) and clamping time (OR 1.01 95% CI 1.00 -1.02; P = 0.018). CONCLUSION: The identification of these predictors allows the development of preventive strategies that could reduce invasive ventilation time, since patients on prolonged mechanical ventilation present greater morbidity and mortality rates.