The patients with COPD ranged from moderately impaired (FEV, = 50 percent predicted, Deo = 17 ml/ min/mm Hg) to severely impaired (FEV\<50 percent predicted, Dco<12 ml/min/mm Hg). There were no significant differences between the treatment and control groups with respect to MEFV parameters, residual volume, heart rate, oxygen saturation, or diffusing capacity (Table 1). [...]