Pressure compensation - CPAP machines

[pwnorris]

Does anyone know if any of the major CPAP/APAP etc. machines are capable of compensating for altitude related pressure differences? I don't see any existing threads on the topic but I may have missed them.

I'm specifically thinking of long transatlantic flights, where the air density is the equivalent of that at an altitude of 8,000 feet. I understand that can lead to a 3% oxygen saturation drop for regular folk.

I was thinking of buying the Resmed Air Mini. Anyone know if this device can compensate for pressure differences?

Thanks...

[Sleeprider]

Your CPAP does not actually provide sea-level pressure, but provides a differential pressure increase regardless of altitude, up to 8000 feet (2500 meters). The clincian manual, and I think the owner's manual for the Airsense 10 states under the machine operating environment under "Technical Specifications":

"Operating Range: Sea level to 8,500' (2,591 m); air pressure range 1013 hPa to 738 hPa"

[pwnorris]

For anyone else interested in the Air Mini performance, the same specifications are printed in the user manual as for the Airsense 10.

i.e. "Sea level to 8,500' (2,591 m); air pressure range 1013 hPa to 738 hPa"

[GWild]

The differential pressure sensor is essentially "dumb" to absolute altitude, doesn't know or care. All it knows is the difference between the two port pressures. They work just as well in a near vacuum (great altitudes) as at a high pressure (even below sea level). So if at sea level or 20,000 feet, the difference will still be whatever the goal is, say 8 cm of H2O.

The other spec is the fan's ability to move air. As altitude grows, fan efficiency decreases. But keep in mind Breckenridge, CO is 9,600 feet. Pretty sure some people there use CPAP machines. They may not operate as efficiently as their Denver cousins... but they do work.

https://www.ncbi.nlm.nih.gov/pmc/article...quirements.

https://www.ncbi.nlm.nih.gov/pmc/article....5.715.pdf

[pwnorris]

Although the manual doesn't say it explicitly, I'd more or less made that assumption, based on the fact my APAP settings are in cm/H2O, though it's good to have it confirmed. Thanks to Sleeprider and GWild for your helpful answers.

Interestingly, Resmed set a maximum limit on operating altitude of 8500' on the Airmini and similar on the Airsense 10, which suggests they planned for their devices to be used on commercial airplanes.