Larry, it sounds like you need high flow O2. If you're dropping into the low 80s with 6 pulse, you're really courting right heart failure and brain damage. Please see your doc and get a portable system that will keep you adequately oxygenated.

yes always.

Jean please pipe in but I use mine when my O2 drops where it shouldn’t be. I stop sometimes and do breathing e revises and it comes up. It throw on the O 2 as well if needed

yes

Jacqueline...I went through Cardiac/Pulminary rehab and they required you to wear oxy. I was using it at level 4 constant flow (Pulm rehab). Cardiac rehab only two of us were on oxy. I would still drop into the 70's (76). I keep forgetting to breathe when I was working out on machines. I go to the YMCA and walk, level 6 pulse and I will drop to 84 to 88. Due to bad back I take two breaks on each lap to let pain subside and catch breathe. Check with your doctor to make sure. Thank you.