Postoperative respiratory failure after cardiac surgery: use of noninvasive ventilation

Abstract

Objectives: To analyze the use of noninvasive ventilation (NIV) in respiratory failure after extubation in patients after cardiac surgery, the factors associated with respiratory failure, and the need for reintubation.

Design: Retrospective observational study.

Setting: Intensive care unit in a university hospital.

Participants: Patients (n = 63) with respiratory failure after extubation after cardiac surgery over a 3-year period.

Interventions: Mechanical NIV.

Measurements and main results: Demographic and surgical data, respiratory history, causes of postoperative respiratory failure, durations of mechanical ventilation and spontaneous breathing, gas exchange values, and the mortality rate were recorded. Of 1,225 postsurgical patients, 63 (5.1%) underwent NIV for respiratory failure after extubation. The median time from extubation to the NIV application was 40 hours (18-96 hours). The most frequent cause of respiratory failure was lobar atelectasis (25.4%). The NIV failed in 52.4% of patients (33/63) who had a lower pH at 24 hours of treatment (7.35 v 7.42, p = 0.001) and a higher hospital mortality (51.5% v 6.7%, p = 0.001) than those in whom NIV was successful. An interval <24 hours from extubation to NIV was a predictive factor for NIV failure (odds ratio, 4.6; 95% confidence interval, 1.2-17.9), whereas obesity was associated with NIV success (odds ratio, 0.22; 95% confidence interval, 0.05-0.91).

Conclusions: Reintubation was required in half of the NIV-treated patients and was associated with an increased hospital mortality rate. Early respiratory failure after extubation (≤24 hours) is a predictive factor for NIV failure.