What your doc explains as trapped CO2 is dynamic hyperinflation, or air-trapping. That's when you're really short of breath and your sats are just fine. He's forgetting that you can be short of breath (sob) because of low O2 sats AND because of air-trapping.

Hello @ Team. This video helps explain how oxygen gets into the bloodstream. You can ignore the math equations here, that is just for how the docs figure out if you need to have portable oxygen or not. For some with emphysema, the damaged lung cells would yield the same low O2 result anyway. While the hypoxia level can easily be measured, IT would still affect every Body differently.
My Doc explains the uncomfortable breathing we call SOB as trapped CO2 gas (but that is not shown in the Diffusion process here). What I feel is actually an increased heart rate to make up for any loss from the COPD damage. While many controlled breathing methods (with coughing) often help, this guy says some exercising may not help much. GOOD News: You get to use what works best for you.
https://youtu.be/vgEA1aK0Eek

I also read about a condition called 'Happy Hypoxia' since Covid19 hit. Even in people with otherwise heathy lungs the O2 saturation had dropped so low they should have experienced what most of US live from day to day. Instead, because their lungs were still diffusing 'normally' they displayed no usual signs of Hypoxia. Of course this didn't last long once the pneumonia fully sets in.
Stay safe and Be well.

I think thats hypoxia. I run into the same problem as you, my o2 can be 96 and I get up and move around and sometimes drops to 88. I have to stop what I'm doing and catch my breathe by standing still or sitting down. Try purse breathing and see if that works, start it before you get up and walk. Let me know if that works. Funny I'm giving you advice and don't do it myself.🤪

It is when you exert yourself and your oxygen stats drop from normal to low. In otherwords when i get up to walk and my 02 stats are 95 and i walk 30 feet and they drop to 85, thats hypoxia. Maybe someone with more expertise can explain it better but that is my understanding 🤔

Hi Gloria. Thank you for giving some feed back on the information I posted. I am glad you now have another tool to get some relief from the many symptoms of this condition. Too many times the suggestions about managing our COPD are made at the expense of other culprits which may be going on within our health. Since we can't live in a vacuum, we shouldn't look for answers to our breathing difficulties that way either. Be well.