Effectiveness of Different Inspiratory-Expiratory Ratios (1:3, 1:4, and 1:5) in Pursed-Lip Breathing on Respiratory Rate, Oxygen Saturation, and Dyspnea in Patients With Chronic Obstructive Pulmonary Disease: A Quasi-Experimental Study

Chronic Obstructive Pulmonary Disease (COPD) is a progressive respiratory condition characterized by persistent airflow limitation, dyspnea, and impaired gas exchange. It remains a leading cause of morbidity and mortality worldwide, with a disproportionately high burden in low- and middle-income countries. Dyspnea is one of the most debilitating symptoms experienced by COPD patients and is closely associated with reduced functional capacity and quality of life. Non-pharmacological interventions, particularly breathing exercises, play an important role in symptom management.

Pursed-lip breathing (PLB) is a simple, low-cost, and widely recommended breathing technique in COPD management. It works by prolonging the expiratory phase, increasing positive airway pressure, preventing airway collapse, and improving ventilation efficiency. Despite its widespread use, there is currently no standardized inspiratory-expiratory (I:E) ratio for PLB. Variations in clinical practice may result in inconsistent outcomes, and evidence comparing different I:E ratios remains limited.

This study aims to evaluate the effectiveness of three commonly recommended I:E ratios (1:3, 1:4, and 1:5) in PLB on respiratory outcomes in patients with stable COPD. The outcomes of interest include respiratory rate, peripheral oxygen saturation (SpO₂), and dyspnea severity as measured by the Modified Borg Scale. By comparing these ratios, the study seeks to identify the most effective breathing pattern for optimizing respiratory function.

This study employs a quasi-experimental design with a pretest-posttest control group approach. A total of 122 participants diagnosed with stable COPD will be recruited from Respira Hospital Yogyakarta, Indonesia. Participants will be randomly assigned into four groups: three intervention groups receiving PLB with different I:E ratios (1:3, 1:4, and 1:5), and one control group receiving standard care without structured PLB intervention.

The intervention will be conducted in a controlled clinical setting. Participants in the intervention groups will be instructed to perform PLB in a seated high-Fowler position for 10 minutes under supervision. Each group will follow a specific breathing pattern: inhalation through the nose followed by prolonged exhalation through pursed lips according to the assigned I:E ratio. The control group will receive standard care without guided PLB.