Effects of resistive expiratory muscle training on lung functions in patients with chronic obstructive pulmonary disease: a randomized controlled trial

Abstract

OBJECTIVE: To determine the effects of resistive expiratory muscle training (EMST-150) on lung function, maximum expiratory pressure and quality of life (QoL) in chronic obstructive pulmonary disease (COPD) atients. METHODS: This randomized controlled trial was conducted on 74 COPD patients, selected through purposive sampling, subsequently randomly assigned to experimental group (n=37) or control group (n=37). Tools used were digital spirometer for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), peak expiratory flow (PEF), Dyspnea grade was calculated using Borg scale and QoL was measured using St. George's Respiratory Questionnaire (SQRG) supervised twice in people with COPD. Baseline data were taken at week-1 before the training and at the completion of the study which was at 6th week. RESULTS: Post-treatment, Experimental Group demonstrated a significant increase in FEV1 compared to Control Group (2.15±0.12 vs. 1.91±0.17, p<0.001). There was a significant difference in FVC between Experimental Group and Control Group after six weeks of treatment (2.26±0.12 vs. 1.96±0.21, p<0.001). No significant difference in PEF was observed between two groups, either before (p = 0.372) or after (p = 0.279) treatment. Regarding QoL for Experimental and Control groups, pre-training SQRG score (Median-Interquartile range) was 55.47 (14.58) and 55.72 (10.435) respectively (p=0.520) and post-training SQRG score was 15.76 (6.875) and 23.91 (6.625) respectively (p<0.001). CONCLUSION: EMST-150 is an effective and beneficial intervention for enhancing lung functions and improved QoL in patients with COPD. These results highlight the potential benefits of incorporating EMST-150 into respiratory rehabilitation programs for individuals with respiratory conditions.