Does prior training affect acute O₂ supply responses during exercise in Desaturator COPD patients?

Background: This study investigated the effects of a prior individualized training program (TP) on the response to acute oxygen supply during exercise in chronic obstructive pulmonary disease (COPD) patients showing exercise-induced desaturation.

Methods: Twenty-two COPD patients (mean [SD] FEV1 = 52.1 [3]% predicted) who desaturated on exercise participated in a TP. Exercise tolerance while breathing compressed air or oxygen was assessed using a walking test (WT) before and after TP. Oxygen flow was individualized.

Results: Before TP, acute oxygen supply improved mean exercise tolerance. But this response was heterogeneous as only 8 patients increased their walking distance with oxygen. TP improved exercise tolerance in the entire population. However, a greater affect of oxygen administration during exercise was not observed after TP. The response to oxygen again showed great disparity as only 6 patients increased their walking distance with oxygen after TP.

Conclusion: The response to oxygen supply during exercise varied among COPD patients. Moreover, despite the clinical benefits of TP, no cumulative effect of TP and oxygen supply was observed during exercise performance.