Information in #52 is correct. This is alternative to mechanical ventilation.
I can't grasp how you would force that much air into the lungs without mechanical ventalation, but maybe that is just my ignorance.
But how many people ARE actually on that drastic level of treatment? one out of ten? One out of twenty, with eight of the rest on normal levels? Surely not everyone in the hospital has to be on some level of oxygen.
Sorry, but I am of the opinion that there is a lot of exaggeration going on.