The effects of inspiratory muscle training on exercise capacity, dyspnea and respiratory functions in lung transplantation candidates: a randomized controlled trial

Objective: To investigate whether inspiratory muscle training would contribute to the improvement of exercise capacity, dyspnea perception and respiratory functions in lung transplantation candidates. Design: Prospective randomized controlled trial. Setting: Pulmonary Rehabilitation center. Subjects: A total of 34 patients with severe lung disease requiring lung transplantation were randomly allocated to either pulmonary rehabilitation plus inspiratory muscle training group (PR + IMT group, n = 17) or pulmonary rehabilitation group (PR group, n = 17) before any lung transplantation operation. Methods: All patients underwent supervised pulmonary rehabilitation program on two days per week for three months. The PR + IMT group received inspiratory muscle training in addition to the standard pulmonary rehabilitation program. The 6-minute walk test, maximal inspiratory pressure, modified Medical Research Concile dyspnea scores and spirometric parameters were measured for each patient. Results: The PR + IMT group had statistically significantly increased in walking distance (100 m, P = 0.03), maximum inspiratory pressure (26 cmH 2 O, P = 0.001) and alveolar volume ratio of carbonmonoxide diffusion capacity (9%, P = 0.02) than PR group. Although both groups demonstrated a statistically significant decrease in the dyspnea score, no significant differences were found between the groups ( P = 0.075). There was no change in spirometric variables in both groups. Conclusion: A greater increase in exercise capacity was observed in the PR + IMT group. Our study showed that inspiratory muscle training improved exercise capacity even further and increased the benefits provided by pulmonary rehabilitation.