my dad has Obstructive (not restrictive) empysema. Hes on 6L at night with CPAP and 5L during day with cannula. We are trying everything we can do raise his O2 sats. 2 questions: 1-has anyone tried and had any success with the cannilas with an oxygen receptacle (like a lanyard) and 2- Does any one know of any other kind of cannula design or accessory that “forces the oxygen down” more than a regular cannula (that is passive)? Thank you!