COMPARATIVE EFFECTS OF PURSED-LIP BREATHING COMBINED WITH THE SIX-MINUTE WALK TEST VERSUS THE SIT-TO-STAND TEST ON DYSPNEA, PEAK EXPIRATORY FLOW RATE, AND OXYGEN SATURATION IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE: A RANDOMIZED COMPARAT

Abstract

Background: Chronic obstructive pulmonary disease (COPD) is among the leading causes of morbidity and mortality worldwide and is characterised by persistent dyspnea and diminished exercise capacity. Field-based functional tests combined with breathing retraining are increasingly used in pulmonary rehabilitation, yet direct comparative evidence on which combination yields superior physiological benefit remains limited. Objective: To compare the effects of pursed-lip breathing (PLB) combined with the six-minute walk test (6MWT) against PLB combined with the sit-to-stand test (STST) on dyspnea, peak expiratory flow rate (PEFR), and arterial oxygen saturation (SpO₂) in patients with COPD. Methods: Sixty patients with mild-to-moderate COPD recruited from the inpatient and critical care units of a tertiary care hospital were allocated by simple random (chit) sampling into two equal groups. Group A (n = 30) performed PLB combined with the 6MWT, and Group B (n = 30) performed PLB combined with the STST, six days a week for one week. Dyspnea (Modified Borg Dyspnea Scale), PEFR (Wright's peak flow meter), and SpO₂ (pulse oximetry) were recorded at baseline and after one week. Within-group change was analysed with the Wilcoxon signed-rank test, between-group differences with the Mann–Whitney U test, and baseline-adjusted comparisons with analysis of covariance (ANCOVA) controlling for baseline score, age, and sex. Results: Both interventions produced significant within-group improvement (p < 0.001). In Group A, the Borg score fell from 3.83 ± 1.21 to 1.35 ± 0.89, PEFR rose from 206.00 ± 58.29 to 368.33 ± 65.92 L/min, and SpO₂ rose from 88.63 ± 3.44% to 97.70 ± 1.09%. In Group B, the Borg score fell from 4.00 ± 1.60 to 2.82 ± 1.58, PEFR rose from 171.67 ± 51.00 to 234.00 ± 51.70 L/min, and SpO₂ rose from 90.83 ± 4.73% to 93.43 ± 3.99%. After ANCOVA adjustment for baseline value, age, and sex, Group A showed significantly greater improvement than Group B on every shared outcome (adjusted Borg difference 1.34 points, adjusted PEFR difference 100.42 L/min, adjusted SpO₂ difference 5.32 percentage points; all p < 0.001). Conclusion: Pursed-lip breathing combined with either the six-minute walk test or the sit-to-stand test improves dyspnea, expiratory flow, and oxygen saturation in patients with COPD, but the combination with the six-minute walk test confers significantly greater short-term physiological benefit and may be preferable where walking space and patient tolerance permit.