Effectiveness of Active Cycle of Breathing Techniques in Patients With Chronic Obstructive Pulmonary Disease: A Randomized Controlled Trial

Overview

This study aims to examine the effects of Active Cycle of Breathing Technique (ACBT) on pulmonary function, sleep quality, depressive symptoms, and dyspnea in patients with Chronic Obstructive Pulmonary Disease. A block-randomized crossover trial will be conducted at the pulmonology outpatient clinic of a regional teaching hospital in eastern Taiwan. Participants aged 40-90 years with physician-diagnosed COPD (post-bronchodilator FEV₁/FVC \< 70%) will be randomly allocated into two groups. The total observation period is 16 weeks with 5 data collection time points: T0 (baseline), T1 (Week 4), T2 (Week 8), T3 (Week 12), and T4 (Week 16). Each intervention period lasts 8 weeks. Primary outcomes are dyspnea (mMRC) and COPD symptom burden (CAT). Secondary outcomes include pulmonary function (FEV₁, FVC), sleep quality (PSQI), and depressive symptoms (DASS-21).

Chronic Obstructive Pulmonary Disease (COPD) is a progressive and irreversible airway obstruction disease. Patients frequently experience dyspnea, sputum retention, repeated exacerbations, reduced exercise tolerance, poor sleep quality, and depressive symptoms. Traditional pulmonary rehabilitation is largely hospital-based and limited by patient age, comorbidities, transportation barriers, and healthcare resource constraints. Active Cycle of Breathing Technique (ACBT) is a non-invasive, low-cost structured breathing method comprising three phases: breathing control, thoracic expansion exercises, and forced expiration technique. Oscillatory Positive Expiratory Pressure (O-PEP) uses a tube valve device to generate oscillatory airflow and positive pressure during expiration, facilitating airway secretion mobilization and clearance. This study adopts a block-randomized crossover design. Group A receives ACBT combined with O-PEP during Weeks 1-8, then standard care during Weeks 9-16. Group B receives standard care during Weeks 1-8, then ACBT combined with O-PEP during Weeks 9-16. Intervention consists of 3 ACBT cycles followed by 10-15 O-PEP expirations, twice daily (at least 8 hours apart), for 8 weeks. All participants receive one-on-one standardized training prior to intervention, with weekly remote follow-up. The O-PEP device will be collected from Group A after Week 8 to prevent carryover. Standard care includes disease education, smoking cessation, self-management skills, and conventional breathing exercises. Data analysis will use Generalized Estimating Equations (GEE) following Intention-to-Treat (ITT) principles.