Since at least the 1960s pulmonary physicians were preaching not to give high flow 02 to COPD patients because they would "hypoventilate" and maybe even hypoventilate to a respiratory rate of zero. Campbell and other emphasized that important therapeutic principle
We talked about elevated carbon dioxide levels suppressing the brainstem systems to drive breathing so that it was only the hypoxia drive that was left and that would be to varying degrees taken away by being given excessive oxygen. In that era it was not uncommon for ambulance drivers ( there were no EMTs in the old days)to give COPD patients 4-6 liter flow O2 only to arrive at the hospital with the patient barely breathing.Those days thankfully are long gone.
This article from Emergency Medic Blog give a good summary review of this topic
H/T to Dr Robert Donnell and his blog for his continuing impressive effort to "keep up" with medical stuff while still practicing medicine as a hospitalist.