Bilevel positive airway pressure in two moments after bariatric surgery

Abstract

SUMMARY OBJECTIVE To investigate the use of Bilevel Positive Airway Pressure (BiPAP) in morbidly obese individuals in two moments following bariatric surgery (Roux-en-Y gastric bypass): post-anesthetic recovery (PAR) and first postoperative day (1PO). DESIGN Randomized and blinded clinical trial. METHODS We studied 40 morbidly obese individuals aged between 25 and 55 years who underwent pulmonary function test and chest X-ray preoperatively, and on the day of discharge (2nd day after surgery). They were randomly allocated into two groups: PAR-G (BiPAP in PAR for one hour), and 1PO-G (BIPAP for one hour on the 1PO). RESULTS In the PAR-G and 1PO-G, respectively there were significant reductions in slow vital capacity (SVC) (p=0.0007 vs. p<0.0001), inspiratory reserve volume (IRV) (p=0.0016 vs. p=0.0026), and forced vital capacity (FVC) (p=0.0013 vs. p<0.0001) and expiratory reserve volume (ERV) was maintained only for the PAR-G (p=0.4446 vs. p=0.0191). Comparing the groups, the SVC (p=0.0027) and FVC (p=0.0028) showed a significant difference between the treatments, while the PAR-G showed smaller declines in these capacities. The prevalence of atelectasis was 10% for the PAR-G and 30% for the 1PO-G (p=0.0027). CONCLUSION Thus, the use of BiPAP in PAR can promote restoration of ERV and contribute to the reduction of atelectasis.