92 yr old dad keeps putting his feet down after i elevate them a d also takes off oxygen-help!

Keep in mind...: 1)no one lives for ever. 2)feeling uncomfortable is misery (even if shouldn't be a "big deal"). 3)dementia makes people finicky-er than without. May have to forgo the feet elevation until/except while he's asleep-or-try ted compression stockings instead of elevation. May have to get "duoderm" or "bioclusive" (thick tape-like patches) to help secure 02 cannula to cheeks & resist picking / fiddling.