Effects of Pulmonary Rehabilitation on Respiratory Function and Thickness of the Diaphragm in Patients with Post-COVID-19 Syndrome: A Randomized Clinical Trial

Abstract

Background: Rehabilitation is an effective method for improving the overall health of patients who have experienced the long-term effects of COVID-19. Methods: The double-blind, randomized prospective study assessed the effectiveness of a 6-week rehabilitation program among post-COVID-19 patients. A total of 59 patients under treatment following COVID-19 were randomly divided into two groups. Both groups completed the same six-week comprehensive exercise training program supported by a respiratory muscle trainer (Threshold IMT) during out-patient sessions. The control group performed placebo IMT. Respiratory muscle strength, chest wall expansion, spirometry, and diaphragm ultrasonography measurements were taken before and after the six weeks. Results: The applied rehabilitation program improved respiratory muscle strength in both the study and control groups (p < 0.001). There was a significant chest circumference increase in the study group (p < 0.001). Spirometric parameters improved in both groups, with the study group showing a greater improvement: 8.02% in FEV1 (p < 0.001), 13.24% in FVC EX (p < 0.001) and 9.67% in PEF (p < 0.001). Rehabilitation also increased diaphragm thickness during maximum inhalation in both groups. Conclusions: Based on the study findings, the specialized outpatient rehabilitation program developed for post-COVID-19 patients has proven to be effective and safe.