Preoperative Inspiratory Muscular Training to Prevent Postoperative Hypoxemia in Morbidly Obese Patients Undergoing Laparoscopic Bariatric Surgery. A Randomized Clinical Trial

Background Morbidly obese patients show an increased risk of postoperative hypoxemia and pulmonary complications when compared with normal weight subjects. The purpose of this study was to determine the effects of preoperative inspiratory muscular training (IMT) on postoperative arterial oxygenation in morbidly obese patients submitted to laparoscopic bariatric surgery. Methods Forty-four morbidly obese patients were randomly assigned to receive either preoperative usual care (control group, n = 21) or preoperative IMT (trained group, n = 23) for a month prior to the date of surgery. Data on oxygenation (PaO 2 /FiO 2 ratio) were obtained at 1 h and at 12 h after surgery (PACU 1 h and PACU 12 h, respectively). Data on maximum static inspiratory pressure (MIP) were obtained before and after the training period, and at postanesthesia care unit (PACU) 12-h time point. Results PaO 2 /FiO 2 was significantly higher in the trained group than in the control group, both at PACU 1 h (305.2 ± 77.6 vs. 248.8 ± 53.8, P = 0.008) and at PACU 12 h (333.5 ± 59.6 vs. 289.7 ± 79.6, P = 0.044). As a consequence, the percentage of patients with relative hypoxemia (PaO 2 /FiO 2 lower than 300 mmHg) at the time of PACU discharge was higher in the control group (57 vs. 17 %, P : 0.006). MIP was significantly higher in the trained group compared with the control group at the preoperative time point (89.87 ± 19.00 vs. 77.00 ± 21.20 cm H 2 O, P = 0.04). Conclusions Preoperative IMT improved postoperative oxygenation and increased inspiratory muscular strength in morbidly obese patients submitted to laparoscopic bariatric surgery.