Clinical Trial Details
— Status: Active, not recruiting
Administrative data
NCT number |
NCT06332820 |
Other study ID # |
202401226RINB |
Secondary ID |
|
Status |
Active, not recruiting |
Phase |
|
First received |
|
Last updated |
|
Start date |
March 20, 2024 |
Est. completion date |
December 31, 2030 |
Study information
Verified date |
March 2024 |
Source |
National Taiwan University Hospital |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Observational
|
Clinical Trial Summary
The definition of obstructive airway disease is a ratio of the forced expiratory volume in
one second (FEV1) to the forced vital capacity (FVC) of less than 0.7, which includes
conditions such as chronic obstructive pulmonary disease, asthma, lymphangioleiomyomatosis,
and bronchiolitis obliterans syndrome. For example, lung obstruction adversely affects many
aspects of a patient's health, such as lung function and exercise capacity. Pulmonary
rehabilitation is widely used in patients with obstructive airway disease, and the
prescription of pulmonary rehabilitation depends on exercise capacity parameters such as peak
oxygen uptake (peak VO2), peak workload, and anaerobic threshold. However, patients often
have difficulty achieving training goals due to severe dyspnea during exercise. Dynamic
hyperinflation is a common cause of dyspnea during exercise in patients with obstructive
airway disease. Investigators aim to alleviate breathlessness by reducing dynamic
hyperinflation, making it easier to achieve training goals. Methods to reduce dynamic
hyperinflation include pursed lip breathing, reducing breathing rate to prolong expiratory
time, using bronchodilators, and undergoing lung volume reduction surgery. Among these
methods, reducing breathing rate to prolong expiratory time may be the most feasible, and
investigators aim to change the rhythm and pace of breathing by adjusting the pedal rate of
cycling exercise. The pedaling rate is typically set at 60 revolutions per minute. The
European Respiratory Society recommended a pedal rate range of 40-70 revolutions per minute
in 2019. There is still no consensus on the relationship between pedal rate and respiratory
rate. This prospective observational study, using a crossover design, aims to investigate the
effects of pedal rate during exercise testing on dynamic hyperinflation and exercise capacity
in patients with obstructive airway disease.
Description:
Obstructive airway disease is defined as forced expiratory volume in one second (FEV1) /
forced vital capacity (FVC) <0.7. It includes chronic obstructive pulmonary disease (COPD),
asthma, lymphangioleiomyomatosis (LAM) and bronchiolitis obliterans syndrome. Pulmonary
rehabilitation is widely utilized in patients with obstructive airway disease. Comprehensive
intervention based on a thorough patient assessment followed by patient-tailored therapies
that include, but are not limited to, exercise training, education, and behavior change,
designed to improve the physical and psychological condition of people. The exercise
prescription for pulmonary rehabilitation is often determined based on exercise capacity. The
exercise capacity includes peaked VO2 (oxygen consumption), peaked work rate, and anaerobic
threshold. They are all measured in cardiopulmonary exercise test (CPET). However, patients
often struggle to achieve training goals due to severe dyspnea. Dynamic hyperinflation is a
common cause of shortness of breath on exertion in obstructive airway disease.
Generally, end-expiratory lung volume (EELV) is relative constant during exercise.
Inspiratory capacity (IC) is increasing during exercise. The IC maneuver is used to monitor
exercise-induced dynamic hyperinflation. Dynamic hyperinflation caused by air trapping, which
increases residual air volume, is a common cause of shortness of breath on exertion in
obstructive lung disease. There are many diagnostic criteria, including a decrease in dynamic
IC of >140mL, a decrease of ≥5% in IC during maximal exercise, or a decrease of ≥10% in IC
during maximal exercise. In a prospective observational study, dynamic hyperinflation
occurred at a higher prevalence (55%) in patients with LAM. Dynamic hyperinflation was
associated with a reduction in FEV1 and higher dyspnea intensity at exercise cessation (R =
-0.53, P-value < 0.001). COPD patients develop dynamic hyperinflation during symptom-limited
incremental work exercise with cycle ergometer. The increase in EELV seems to be the best
predictor of dyspnea.
The pedaling rate is typically set at 60 revolutions per minute in National Taiwan University
Hospital. The average respiratory rate for a total of 31 patients is 29 breaths per minute.
2019 European respiratory society suggested that maintaining over a wide range of pedaling
rates (40-70 revolutions per minute) in CPET. The evidence of the optimal pedaling rate
during exercise obstructive airway disease is limited. The current consensus remains
inconclusive on whether a lower pedaling rate will result in a reduction of breathing speed,
subsequently improving dynamic hyperinflation, and ultimately leading to an improvement in
exercise capacity. This prospective observational study, employing a crossover design, aims
to investigate the impact of pedaling rate during exercise tests on dynamic hyperinflation
and exercise capacity in individuals with obstructive airway disease.