Effect of Active Physiotherapy With Positive Airway Pressure on Pulmonary Atelectasis After Cardiac Surgery: A Randomized Controlled Study

Abstract

The authors investigated the effect of active work with positive airway pressure (PAP) in addition to chest physiotherapy (CP) on pulmonary atelectasis (PA) in patients undergoing cardiac surgery with cardiopulmonary bypass. A randomized controlled study. At a single-center tertiary hospital. Eighty adult patients undergoing cardiac surgery (coronary artery bypass grafting, valve surgery, or both), and presenting with PA after tracheal extubation on postoperative days 1 or 2, were randomized from November 2014 to September 2016. Three days of CP, twice daily, associated with active work with PAP effect (intervention group) versus CP alone (control group). Pulmonary atelectasis was assessed by using the radiologic atelectasis score (RAS) measured from daily chest x-rays. All radiographs were reviewed blindly. Among included patients, 79 (99%) completed the trial. The primary outcome was mean RAS on day 2 after inclusion. It was significantly lower in the intervention group (mean difference and 95% CI: -1.1 [-1.6 to -0.6], p < 0.001). The secondary outcomes were the sniff nasal inspiratory pressure measured before and after CP and clinical variables. Sniff nasal inspiratory pressure was significantly higher in the intervention group on day 2 (7.7 [3.0-12.5] cmH2O, p=0.002). The respiratory rate was lower in the intervention group (-3.2 [95% CI -4.8 to -1.6] breaths/min, p < 0.001) on day 2. No differences were found between the 2 groups for percutaneous oxygen saturation/oxygen requirement ratio, heart rate, pain, and dyspnea scores. Active work with the PAP effect, combined with CP, significantly decreased the RAS of patients undergoing cardiac surgery after 2 days of CP, with no differences observed in clinically relevant parameters.