Effect of inspiratory muscle training on patients undergoing bariatric surgery: a systematic review

ABSTRACT Studies have shown that among the various techniques that involve chest physical therapy, the inspiratory muscle training (IMT) is essential in the recovery of lung function and in preventing respiratory complications. However, the effect of IMT on patients undergoing bariatric surgery is still inconclusive. The aim of this study was to systematically review randomized and controlled trials that assessed the effect of IMT compared with sham IMT, standard physical therapy (breathing exercises and early ambulation) or no intervention in the lung function on patients undergoing bariatric surgery. The search was conducted in PubMed/MEDLINE, Cochrane, TRIP, PEDro and Scopus databases with no publication year or language limits, following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement. Two reviewers independently selected the studies, extracted the data, and assessed the risk of bias. From 2,184 potentially eligible studies, two studies were included. Bias risk criteria were adapted and divided into nine main areas using the Cochrane Handbook. This review included 62 participants, being 30 allocated to receive Threshold® IMT device, but in different periods: preoperative and postoperative. IMT promoted increased maximal inspiratory pressure (MIP) in relation to standard physical therapy, but no significant differences were found in maximal expiratory pressure (MEP). The studies showed low and unclear bias risk. IMT seems to be the most effective treatment in comparison with standard physical therapy alone in pre- or postoperative period. However, there is no solid evidence for clinical decision-making.