Effect of Pursed-Lip Breathing With Different I:E Ratios on Respiratory Outcomes in COPD Patients

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

The goal of this clinical trial is to evaluate whether different inspiratory-expiratory (I:E) ratios in the pursed-lip breathing (PLB) technique can improve respiratory outcomes in patients with stable Chronic Obstructive Pulmonary Disease (COPD) aged 40 years and older. The primary purpose is to determine whether a specific breathing intervention can improve respiratory function.

The main questions it aims to answer are:

Does PLB with different I:E ratios (1:3, 1:4, and 1:5) reduce respiratory rate in COPD patients? Does PLB with different I:E ratios improve oxygen saturation and reduce dyspnea severity?

Researchers will compare PLB with I:E ratios of 1:3, 1:4, and 1:5 and a control group receiving standard care to see if different ratios produce different effects on respiratory rate, oxygen saturation, and dyspnea levels.

Participants will:

Perform pursed-lip breathing using assigned I:E ratios (1:3, 1:4, or 1:5) for 10 minutes Be assigned to either an intervention group or a control group (standard care) Have their respiratory rate measured before and after the intervention Have their oxygen saturation measured using a pulse oximeter Report their dyspnea level using the Modified Borg Scale before and after the intervention

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.

Outcome measurements will be taken at baseline (pre-intervention) and immediately after the intervention. Respiratory rate will be measured by direct observation for one minute, oxygen saturation will be assessed using a calibrated pulse oximeter, and dyspnea will be evaluated using the Modified Borg Scale (0-10). Data will be analyzed using appropriate statistical tests to compare within-group and between-group differences.

This study is expected to contribute to the development of evidence-based guidelines for PLB implementation in COPD management, particularly in determining the optimal I:E ratio. The findings may help standardize clinical practice, improve respiratory outcomes, and enhance the quality of life of COPD patients. Additionally, the results may provide a foundation for future research on breathing techniques and non-pharmacological interventions in respiratory care.

Inclusion Criteria:

• Diagnosed with stable COPD
• Age ≥ 40 years
• Able to follow breathing instructions
• Willing to participate and provide informed consent

Exclusion Criteria:

• Cognitive impairment or decreased consciousness
• Severe cardiovascular disease (heart failure, coronary artery disease, pulmonary hypertension)
• Asthma-COPD overlap (ACO)
• Acute respiratory infection (e.g., pneumonia)
• Neuromuscular disorders affecting respiratory muscles