Effects of Expiratory Muscle Training on Peak Cough Flow, Respiratory Muscle Strength and Functional capacity in individuals with Chronic Obstructive Airway Disease: A Single Blinded Randomized Controlled Trial

NEED OF STUDY In obstructive lung disease, factors such as inflammation, bronchoconstriction, excessive mucus, and decreased elastic recoil lead to an earlier small airway closure during expiration and more significant airway resistance.18 This results in greater work of breathing. Studies have shown that not only inspiratory muscle dysfunction but even expiratory muscle dysfunction is seen in patients with COPD. The weak expiratory muscles result in insufficient force to move the mucus or other secretions proximally to clear the airways, thereby increasing the risk of infections and exacerbations17. Weakened expiratory muscles contribute to ineffective exhalation, resulting in air trapping within the lungs (hyperinflation) and reduced ability to fully empty the lungs during breathing cycles.18 Addressing these effects through therapies like Expiratory Muscle Training (EMT) can help to improve airflow and ventilation in the lungs, reducing air trapping, mucus clearance, and exercise tolerance12 and overall respiratory function for individuals with obstructive lung diseases. Also, EMT can alleviate some of this fatigue by training the expiratory muscles, thereby reducing the workload on these muscles during exhalation. There are more than 500 studies available on Inspiratory Muscle Training, whereas only less than 40 studies were found on Expiratory muscle training. More emphasis is given

on Inspiratory Muscle Training in COPD patients, whereas, effects of Expiratory muscle training is poorly understood in Indian context. Hence, there is a need to study the effects of expiratory muscle training on expiratory muscle strength, peak cough flow and functional capacity in patients with Obstructive Airway Disease.

AIM: To assess the effects of 4 weeks of Expiratory muscle training on Peak cough flow, Respiratory muscle strength and Functional capacity in individuals with moderate to severe Chronic Obstructive Airway Disease.

OBJECTIVES: 1. To assess the Peak cough flow, Respiratory muscle strength, and functionalcapacity Pre and Post 4 weeks of conventional physiotherapy (control) group in individuals with Chronic Obstructive Airway Disease. 2. To assess the Peak cough flow, Respiratory muscle strength and functional capacity pre and post 4 weeks of conventional physiotherapy and Expiratory muscle training (Interventional) group in individuals with Chronic Obstructive Airway disease. 3. To compare both the groups.

STUDY PROCEDURE Patients coming to Chest Medicine OPD and Physiotherapy OPD and diagnosed with Obstructive airway disease by a Pulmonary Physician will be screened and those meeting the Inclusion criteria will be recruited for the study after explaining the study protocol and taking their written consent. The participants will be randomly assigned into Group A i.e. Control group and Group B i.e. Interventional group by simple randomization using Chit Method. 62 chits will be made such that there are 31 chits of each group to ensure equal number in both groups. Each participant will be asked to pick up a chit as they are recruited and will be assigned to the group that is mentioned in the chit. The participants of Group A will be treated on Mondays, Wednesdays and Fridays of the week for 4 weeks while the Group B will be treated on Tuesdays, Thursdays and Saturdays of the week for 4 weeks so that there is no interaction between the groups. The participants demographic data such as age, gender, severity and duration of disease and outcome measures as mentioned previously will be recorded. The endpoint of the study is 4 weeks duration. If the participant becomes breathless during the study, he / she will be immediately discontinued from the study and will be referred to Chest Medicine physician for further management. Participants will be continued their regular Medications as prescribed by Chest Physician during the intervention period.

DATA ANALYSIS • Peak Cough Flow rate, PImax, PEmax, 6 Min walk distance will be collected pre and post intervention in both groups and will be analysed using SPSS software. • Descriptive statistics of Mean standard Deviation, median range Confidence Interval etc. determined. • An paired t-test (parametric data) or Wilcoxon signed rank test (non-parametric data) will be used pre and post for analysis in Conventional physiotherapy group. • An paired t-test (parametric data) or Wilcoxon signed rank test (non- parametric data) will be used pre and post for analysis in Interventional group. • Between group analysis will be done using unpaired t test (parametric data) and Mann Whitney U test (non-parametric data). • Test for significance will be set at 0.05. • If the intervention group shows significant effect, then effect size using Cohen’s ‘d’ will be determined.