Bronchodilators and Dynamic Lung Mechanics During Exercise in COPD: Protocol for a Randomised, Placebo-controlled Crossover Trial

What this Trial Is About

Researchers are evaluating the effects of short-acting bronchodilators on lung function and breathlessness in people with chronic obstructive pulmonary disease (COPD). The study aims to determine whether these bronchodilators reduce resistance in the smallest airways of the lungs during exercise, and if this leads to improvements in breathlessness and exercise ability. Small airway disease is a major cause of airway obstruction in COPD, and better medication delivery to these airways could help ease symptoms such as shortness of breath during activity. Participants will receive either a combination of short-acting bronchodilators (salbutamol sulfate and ipratropium bromide) or a placebo (normal saline) via nebulizer in a randomized, crossover design. The study includes three visits over 2 to 3 weeks. The first visit assesses eligibility and lung function, including spirometry and exercise capacity tests. The second and third visits involve exercise tests with either the bronchodilator or placebo, with detailed lung measurements taken before and after treatment. During the exercise visits, participants will pedal on a stationary bike while lung function and breathing mechanics are closely monitored using specialized equipment. Measurements include airway resistance, lung volumes, diaphragm electrical activity, and respiratory pressures. Breathlessness and leg fatigue will be assessed using a scale, and vital signs will be monitored throughout. The main outcome is airway resistance measured at multiple time points during exercise. The total participation time spans about 2 to 3 weeks.

Bronchodilators and Lung Mechanics During Exercise in COPD