Originally Posted by
bucoops
My CPAP machine can supply at up to 20 cmH2O. Not sure how that translates but when I first started using it, it woke me in the middle of the night with the feeling of drowning in air. A very disconcerting feeling I can assure you. Obviously this was at normal atmospheric level, not FL45 or so.
That comes out to about 19mbar, a fairly high setting from what I have read, but still only amounts to 2% over ambient pressure. Just goes to show how 'sensitive' ones lungs are and how accustomed we are to 'normal' breathing.