抄録
Dyspnea has been implicated in the prognosis of patients with chronic obstructive pulmonary disease (COPD) . We examined the relationship between exertional dyspnea during walking and oxygen utilization, as well as the pulmonary hemodynamics at rest in patients with stable COPD. A sixminute walking test (6 MWT) and cardiac catheterization was performed in twenty-four subjects, whereby each patient was instructed to walk as far as possible for six minutes, during which the distance and degree of dyspnea were recorded each minute on a 150-mm visual analog scale (VAS) . In all patients there was a significant linear relationship between dyspnea and the distance walked over time. From these results, we obtained a ratio of induced dyspnea to distance (VAS I distance) during the 6MWT. There was significant correlation between VAS I distance and FEV1, oxygen extraction ratio (ER), PaO2, and mixed venous oxygen tension (PvO2) . However, the PaCO2 and pulmonary arterial mean pressure (mPAP) showed no correlation with VAS / distance. These results suggest that COPD patients with severe exertional dyspnea have an impairment of oxygen utilization at rest.
