Effects of inspiratory muscle training on muscular and pulmonary function after bariatric surgery in obese patients.

BACKGROUND: This study seeks to assess the effect of inspiratory muscle training (IMT) on pulmonary function, respiratory muscle strength, and endurance in morbidly obese patients submitted to bariatric surgery.

METHODS: Thirty patients were randomly assigned to sham muscular training, or to IMT with a threshold device (40% of maximum inspiratory pressure, MIP), for 30 min/day, from the 2nd until 30th postoperative (PO) day. All of them were submitted to a standard respiratory kinesiotherapy and early deambulation protocol. Data on spirometry, maximum static respiratory pressures, and respiratory muscle endurance were collected on the PO days 2, 7, 14, and 30 in a blinded matter.

RESULTS: IMT enabled increases in PO MIP and endurance, and an earlier recovery of the spirometry parameters FEV(1), PEF, and FEF(25-75%). Comparing to preoperative values, MIP was increased by 13% at the 30th PO day in the trained group, whereas control group had a reduction of 8%, with higher values for the IMT group (30th PO, IMT-130.6 ± 22.9 cmH(2)O; controls-112.9 ± 25.1 cmH(2)O; p < 0.05). Muscular endurance at the 30th PO day was increased in the trained group comparing to preoperative value (61.5 ± 39.6 s vs 114.9 ± 55.2 s; p < 0.05), a finding not observed in the control group (81.7 ± 44.3 vs 95.2 ± 42.0 s).

CONCLUSIONS: IMT improves inspiratory muscle strength and endurance and accounts for an earlier recovery of pulmonary airflows in morbidly obese patients submitted to bariatric surgery.