Originally Posted by David Rowland
Originally Posted by Geoff Vincent
Rick, very interesting! I believe it’s ventilation of CO2 that drives most respiration, not hypoxia. In other words our body doesn’t wait until it’s hypoxemic before you feel the need to breathe which is good. The brain cells do not tolerate lack of oxygen long before they suffer permanent injury. I guess those high flyers are ventilating well, so they breath the rate and depth they would on the ground. With the low oxygen mix up high, it’s not enough.

Quote
Continuous positive airway pressure (CPAP) is a form of positive airway pressure (PAP) ventilation in which a constant level of pressure greater than atmospheric pressure is continuously applied to the upper respiratory tract of a person.

Interesting. The same idea as aircraft pressurization except on an individual basis? How much additional pressure over atmospheric pressure can a CPAP machine provide?

Aren’t most pressurized aircraft pressurized to 8psi which provides an 8000 foot pressure altitude inside the cabin at typical cruising altitude? I think the 787 has a higher pressurization level, at least that is what I seem to remember from some marketing stuff.
David, I think the biggest difference between CPAP and a pressurized cabin is in the pressurized cabin you have artificial pressure both inside and outside the lungs. You’re submersed in the pressure bath, so to speak. With CPAP, your body is exposed to one pressure but your airway is given a higher one. The machine blows it in to inflate your lungs, not requiring the negative pressure usually required to inhale.

Geoff
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N10473
Huh I don't know

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