Impact of Integrative Cardiopulmonary Exercise Testing (22)
D’Urzo et al reported that resting Deo and resting 02 saturation would suggest which patients with COPD would desaturate during exercise. They found a strong correlation between these variables, but they only accounted for 65 percent of the observed variance in exercise 02 saturation. Finally, we have recently found that about two thirds of a group of patients with moderately severe to severe COPD had evidence of metabolic acidosis during exercise. This finding is significant because it suggests that 02 delivery may become limited during exercise in these patients, a predominantly cardiovascular function. This concept has important implications for treatment and rehabilitation programs. proventil inhaler
Therapy of COPD may be usefully tested during exercise, especially if the goal of treatment is to relieve exertional dyspnea or increase exercise tolerance. For example, Brown et al found that inhaled atropine sulfate lowered the 02 cost of breathing in patients with COPD, although there was no effect on mean maximum exercise capacity. In another study, alprazolam did not prove effective in relieving exercise dyspnea or improving exercise capacity in patients with COPD.