Can inspiratory muscle training benefit patients after stroke? A systematic review and meta-analysis of randomized controlled trials

Objectives: The aim of this study was to investigate the effects of inspiratory muscle training in post-stroke patients and to explore the effective training protocol. Data sources: PubMed/Medline, Web of Science, Scopus, Embase, Cochrane database, China National Knowledge Infrastructure, and China Science Periodical Database were searched through April 2020. Review methods: Trials examining effects of inspiratory muscle training on pulmonary function, cardiopulmonary endurance, pulmonary infection incidence, and quality of life in post-stroke patients were included. Subgroup analysis was performed to compare different training programs. Mean differences and risk ratios with 95% confidence intervals were presented. Risk of bias was assessed with the Cochrane tool. Results: Thirteen randomized controlled trials involving a total of 373 participants were identified. Meta-analysis conducted in 8 out of 13 trials revealed evidence for beneficial effects of inspiratory muscle training on forced vital capacity (MD: 0.47, 95% CI: 0.28-0.66), forced expired volume in 1 second (MD: 0.26, 95% CI: 0.18-0.35), 6-minute walk test (MD: 52.61, 95% CI: 25.22-80.01), maximum inspiratory pressure (MD: 18.18, 95% CI: 5.58-30.78), inspiratory muscle endurance (MD: 19.99, 95% CI: 13.58-26.40), and pulmonary infection incidence (RR: 0.11, 95% CI: 0.03-0.40). Omitting individual trials from the meta-analysis did not significantly change the results. The effective inspiratory muscle training protocol was suggested by subgroup analysis with three repetitions per week and more than 20 minutes per day for three weeks. Conclusion: Inspiratory muscle training can be considered as an effective intervention for improving pulmonary function and cardiopulmonary endurance, and reducing pulmonary infection incidence in patients after stroke.