Can inspiratory muscle training benefit patients with COVID-19? A systematic review and meta-analysis

The possible benefits of inspiratory muscle training (IMT) on mechanical and clinical outcomes in patients with Coronavirus disease-2019 (COVID-19) remain controversial. We conducted a meta-analysis to evaluate the effect of IMT in the rehabilitation strategy of patients with COVID-19. The Pubmed, Embase, Web of Science (WOS), and Cochrane Central Register of Controlled Trials (CENTRAL) were searched to identify trials evaluating the efficacy of IMT in the treatment of patients with COVID-19. The primary outcome included change from baseline of VO2max, maximal inspiratory pressure (PImax), 6-min walk test(6MWT), forced expiratory volume in the first second predicted (FEV1%pred), and quality of life (QOL). Six studies with 349 participants were analyzed. Significant improvements were found in change from baseline of VO(2)max (MD: 4.54, 95% confidence interval [CI]: 1.79-7.30, Z = 3. 32, I-2 = 0, p = 0.001), PImax (MD: 21.43, 95% CI: 1.33-41.52, Z = 2.09, I-2 = 90%, p = 0.04), 6MWD (MD: 40.13, 95% CI: 24.92-55.35, Z = 5.17, I-2 = 0, p < 0.00001) and FEV1%pred (MD: 8.73, 95% CI 3.07-14.39, Z = 3.02, p = 0.002) while no statistical improvements were found in QOL (SMD: 0.70, 95% CI: 0.37-1.03, Z = 4.15, I-2 = 89% p = 0.32) between IMT group and control group. The application of IMT might elicit mechanical and clinical improvement in patients with COVID-19. IMT could be recommended as an effective strategy of pulmonary rehabilitation for COVID-19. However, the proper timing, optimal duration, as well as appropriate frequency and intensity of IMT remain uncertain and further studies are needed.

Automated summary

The possible benefits of inspiratory muscle training (IMT) in patients with COVID-19 remain controversial. A meta-analysis was conducted and it was found that IMT could lead to improvements in mechanical and clinical outcomes, such as VO2max, PImax, 6MWT, and FEV1%pred. However, no statistical improvements were observed in quality of life (QOL). IMT could be recommended as an effective strategy for pulmonary rehabilitation in COVID-19 patients, but further studies are needed to determine the optimal timing, duration, frequency, and intensity of IMT.