[The effect of exercise on blood gases and oxygen transport in patients with chronic obstructive pulmonary disease].

The effect of exercise on pulmonary gas exchange and oxygen transport was studied in 42 patients with COPD. Arterial PO2 increased and arterial PCO2 did not change significantly in 25 patients (group A). Arterial PO2 decreased and arterial PCO2 increased in the remaining 17 patients (group B). In group A, P(A-a)O2,Qs/Qt decreased remarkably, oxygen transport and oxygen extrication increased significantly during exercise when compared with that of group B. Our data imply that PO2 changes of COPD patients during exercise may be related to the patient's ventilation, pulmonary gas exchange and mixed venous PO2 levels.