I'm not sure what you're asking. I am on oxygen at night, while ambulatory, and while doing anything strenuous. Been own it 4 years now.
Your pulmonologist will have you do a walk test to see if you need to be on oxygen.

I'm 81 and have stage 3 emphazema. I've been on oxygen therapy for over a year. It helps. Also a liquid drug called Acetylcysteine. This drug is taken orally (mixed with about 1 ounce of juice). It takes a couple of weeks before you feel the benefits, but it definitely helps to thin and expel phlegm. BTW, I have no other health issues. 63 years of smoking caused my COPD. Good luck.