Bronchodilators and Oxygen Kinetics With Exercise in Chronic Obstructive Pulmonary Disease (COPD) Patients
Status:
Completed
Trial end date:
2009-07-01
Target enrollment:
Participant gender:
Summary
Hypothesis: The reduction of dynamic hyperinflation and its negative effects on the
respiratory system following a bronchodilator could lead to an improvement of cardiac
function in terms of increased cardiac output. This may enhance oxygen delivery to the
exercising muscles in COPD patients. Bronchodilator administration may also have an indirect
effect on V'O2 kinetics via its action on cardiovascular and pulmonary variables.
Objectives:
1. To evaluate the effects of a bronchodilators on V'E , V'CO2 , and V'O2 kinetics in COPD
during constant work-rate cycle exercise, and to evaluate whether bronchodilators will
accelerate, indirectly, phase 2 kinetics (usually slower in COPD patients than normal
subjects) and shorten t for V'E, V'CO2 , and V'O2 and shorten half-times for HR and O2
pulse, thus showing an improvement of oxygen transport to the peripheral active muscles.
2. To determine the impact of a bronchodilator-induced reduction in dynamic hyperinflation,
and its effects on cardiovascular and pulmonary function, on exercise limitation in
COPD.