Pulmonary effects of noninvasive ventilation combined with the recruitment maneuver after cardiac surgery

Abstract

Background: The aim of our study was to evaluate the pulmonary effects of noninvasive ventilation (NIV) with or without recruitment maneuver (RM) after open heart surgery.

Methods: One-hundred patients undergoing coronary artery bypass surgery were randomized into four groups after the operation: 1) RM with sustained inflation during mechanical ventilation postoperatively (RM group, n = 25); 2) RM combined with NIV applied for 1/2-h periods every 6 h in the first postoperative day after tracheal extubation (RM-NIV group, n = 25); 3) NIV after tracheal extubation (NIV group, n = 25); and 4) a control group consisting of patients receiving neither RM nor NIV (control group, n = 25). Pulmonary function tests, oxygenation index, and atelectasis on chest radiograph were evaluated and compared among the groups.

Results: RM provided higher arterial oxygen levels during mechanical ventilation and after tracheal extubation compared to other interventions. Oxygenation was better in the RM-NIV and NIV groups than in the control group (P = 0.02 and P = 0.008, respectively) at the end of the study. The postoperative atelectasis score of the control group (median: 1) was higher than those of the RM (1; P = 0.03), RM-NIV (0; P < 0.01) and NIV (0; P < 0.01) groups. Pulmonary function of the NIV groups on postoperative day 2 was better than in the other groups, whereas the tests were similar among the groups on postoperative day 7.

Conclusions: NIV associated with RM provided better oxygenation both during and after the mechanical ventilation period. NIV either alone or in combination with RM provided lower atelectasis scores and better early pulmonary function tests compared to the control group, without a significant difference regarding the duration of mechanical ventilation, intensive care unit stay, and the length of hospitalization. NIV combined with RM is recommended after open heart surgery to prevent postoperative atelectasis and hypoxemia.