I am in the process of helping someone with respiratory problems. This person needed inhalers at times but we do have an oxygen concentrator that I run, mostly at night now - at least this got them off inhalers (keeps phlegm at a point where it can be cleared). Hyperbaric oxygen would be good but the nit-wits that run this stuff in our area would not do it for anything but wound healing (did not enquire about this, just already know how they roll).