The Effect of Inhaled Nitric Oxide on Deadspace in COPD
Status:
Recruiting
Trial end date:
2022-09-01
Target enrollment:
Participant gender:
Summary
Chronic obstructive pulmonary disease (COPD) is a progressive disease of the respiratory
system that generally develops as a result of smoking. Most people with COPD are classified
as having "mild" disease severity and may not have significantly impaired lung function (e.g.
flow) as measured by traditional lung function tests. However, multiple studies have shown
that patients with mild disease already have significant damage to the small airways and
blood vessels of the pulmonary system. This results in a considerable portion of the lung
that does not participate in gas exchange, a phenomenon called physiologic dead space. Mild
COPD patients develop symptoms of intolerable breathlessness early in exercise compared with
healthy individuals. Previous studies have shown that pulmonary vasodilators, which locally
increase blood vessel radius, may improve gas exchange and reduce symptoms of breathlessness
in patients with mild COPD. Therefore, the objective of this study is to determine the effect
of reducing dead space with a pulmonary vasodilator on the intensity of breathlessness during
exercise in patients with mild COPD. This five visit, double-blinded, placebo-controlled
crossover study will test the impact of inhaled nitric oxide, a direct vasodilator, during
cardiopulmonary exercise on dead space and breathlessness intensity. Use of an esophageal
catheter during testing will additionally permit measurement of neural drive to breathe and
pulmonary mechanics throughout the protocol. Though patients with mild COPD represent the
majority of the COPD population, their symptoms remain poorly managed by current, inefficient
standard of care. The proposed study will examine dead space reduction as a novel therapeutic
target for improving breathlessness and exercise tolerance in patients with mild COPD.