Peak Expiratory Flow Rate Versus Acapella on Pulmonary Function in Elderly Post-Covid-19 Patients

Background: Post-COVID-19 recovery in older adults is frequently complicated by persistent dyspnea and impaired oxygenation, prompting use of positive expiratory pressure (PEP) techniques such as oscillatory PEP (Acapella) and bottle-based PEP (blow bottle). Objective: To compare Acapella versus blow bottle PEP for improving oxygen saturation, peak expiratory flow rate (PEFR), dyspnea, and six-minute walk distance (6MWD) in elderly post-COVID-19 patients over one week. Methods: In this randomized clinical trial conducted at Tehsil Hospital Kot Addu over six months, 48 post-COVID-19 patients aged 50–65 years were allocated to Acapella (n=24) or blow bottle PEP (n=24) delivered three times daily for 7 days. Oxygen saturation, PEFR, dyspnea (modified Borg), and 6MWD were measured at baseline and after intervention. Between-group comparisons were performed using rank-based testing. Results: At Day 7, oxygen saturation differed significantly between groups (mean rank 31.69 blow bottle vs 17.31 Acapella; p<0.001), indicating superior oxygenation distribution in the blow bottle group. PEFR showed no between-group difference at Day 7 (mean rank 25.23 vs 23.77; p=0.717), and 6MWD remained comparable (mean rank 24.50 vs 23.50; p=0.882). Conclusion: Over one week, blow bottle PEP demonstrated superior improvement in oxygen saturation relative to Acapella, while PEFR and functional walking capacity did not differ, supporting PEP as an oxygenation-focused adjunct within broader post-COVID rehabilitation.