Pulmonary and Functional Rehabilitation Improves Functional Capacity, Pulmonary Function and Respiratory Muscle Strength in Post COVID-19 Patients: Pilot Clinical Trial

Background: Patients affected by COVID-19 may develop an impaired lung function, with reduced lung capacities and volumes, respiratory muscle weakness, changes in radiographic and tomographic findings, limitations in exercising, decreased functional capacity, depression, anxiety and reduced quality of life. Thus, we aimed to analyze the effects of a pulmonary and functional rehabilitation program on the functional capacity, lung function and respiratory muscle strength in patients who were affected by COVID-19 syndrome. Methods: This is a pilot clinical trial, composed of post-COVID-19 patients with mild, moderate or severe involvement, in which, they underwent a pulmonary and functional rehabilitation program. Patients were evaluated for functional capacity by the 6 min walk test, pulmonary function by spirometry, respiratory muscle strength by manovacuometry, handgrip strength by dynamometry, quality of life by the COPD Assessment Test and functional status by the PCFS. After the initial assessments, the patients performed the rehabilitation protocol in 16 sessions (inspiratory muscle training, aerobic exercise and peripheral muscle strength) and, at the end, they were evaluated again. Results: A total of 29 patients completed the program (12.7 +/- 2.7 sessions). The functional capacity increased in meters walked from 326.3 +/- 140.6 to 445.4 +/- 151.1 (p < 0.001), with an increase in the predicted value from 59.7% to 82.6% (p < 0.001). The lung function increased in liters from 2.9 +/- 0.8 to 3.2 +/- 0.8 (p = 0.004) for forced vital capacity and from 2.5 +/- 0.7 to 2.7 +/- 0.7 (p = 0.001) for forced expiratory volume in the first second. The respiratory muscle strength increased in cmH(2)O from 101.4 +/- 46.3 to 115.8 +/- 38.3 (p = 0.117) for inspiratory pressure and from 85.8 +/- 32.8 to 106.7 +/- 36.8 (p < 0.001) for expiratory pressure. Conclusions: The pulmonary and functional rehabilitation program provided an improvement in the functional capacity, pulmonary function and respiratory muscle strength in post-COVID-19 patients, restoring their quality of life.