Role of Inspiratory Muscle Training on Pulmonary Rehabilitation in Patients with COVID-19: A Pilot Study

BACKGROUND: Inspiratory muscle training has been introduced as one of the effective methods in pulmonary rehabilitation, and attention to this technique in patients with COVID-19 is still being studied. MATERIALS AND METHODS: In the present study 52 patients who have undergone the period of the COVID-19 disease were randomly divided into two groups. In the control group, in addition to the routine treatment prescribed by a specialist physician, rehabilitation was performed by performing diaphragmatic breathing exercises, pursed-lips breathing, chest expansion, and simple stretching exercises. In the intervention group in addition to the rehabilitation program provided to the control group, patients used an inspiratory muscle training device. This pulmonary rehabilitation program was performed twice a day and 30 repetitions each time with a two-minute rest after every 10 exercises. After 4 weeks, patients in both groups were referred to the hospital for reassessment of the distance of the 6-minute walk test, SF-12 questionnaire results, dyspnea, and S-index. To compare quantitative variables between the two groups we utilized a student t-test. Type one error was put at P≤0.05. RESULTS: The comparison of 6MWT values shows that the mean of this index in the intervention group is significantly higher than the control group (p = 0.002). Also, the S-index of the two groups showed a significant difference (p=0.024). Results show a significant increase in the SF-12 quality of life questionnaire in patients using IMT (p=0.001). CONCLUSION: IMT improves pulmonary functions, 6MWT, and SF-12 Questionnaire in recovered COVID-19 patients.