[Distance walked in 10 minutes, pulmonary function, and pulmonary hemodynamics during exercise, in patients with...

We examined relationships among the distance walked in 10 minutes (10 MD), pulmonary function, and pulmonary hemodynamics during exercise on a bicycle ergometer, in patients with chronic pulmonary emphysema who had dyspnea of grade III to IV on the Hugh-Jones scale. The 10 MD did not correlate significantly with desaturation during the 10-minute walk, but it did correlate significantly with the percent of predicted maximum voluntary ventilation, and it correlated negatively with airway resistance. These findings indicate that ventilatory impairment is an important factor limiting 10 MD in these patients. Also 10 MD correlated significantly and positively with %DLco; and it correlated negatively with the index of pulmonary vascular resistance and with the ratio of the change in pulmonary arterial pressure to the change in cardiac index during exercise. (delta Ppa/delta CI). These findings indicate that impairment of pulmonary circulation may also limit the 10 MD and exercise tolerance in patients with chronic pulmonary emphysema.