Apnea and high altitude

[djpax13]

So I’ve been using the CPAP for a couple of weeks now and I’ve had great results. AHI down to about 2 from 112. Still fine-tuning, but overall it’s been great. 

Something curious happened last night, however. I am traveling and slept at a much higher elevation: 8,000 feet versus my usual 250 feet. During my waking hours I noticed no ill effects due to the altitude, but at night my AHI jumped to 17. My OAs were slightly elevated, but my CAs were the biggest cause of the higher AHI. I also definitely feel more exhausted today. I did some cursory research, and it does seem there might be a connection between increase in elevation and number of CAs. I haven’t had a chance to review OSCAR yet as I am still on the road. 

So my question is this: have any of you experienced this phenomenon? If you have, do your numbers go back down after acclimating to the higher elevation?

Thank you for your thoughts!

[Sleeprider]

This is a very common thing to happen on CPAP, especially if you are using EPR. High altitudes can really play havoc with your sleep until you adjust. It would be interesting to compare charts from your normal at-home and at altitude. It is not a serious problem and will subside when you return to your normal elevation. Many people find Diamox (acetazolamide) can offset the effects of altitude including increased CA. The CPAP makes this noticeable because you see the data, but if not for that, I bet you feel fine.

[Nightynite]

The air is thinner at altitude vs. sea level. So you need to adjust for that difference. How much ? I don’t know, sorry. But I can tell you from living in Colorado for 35 yrs @ 5k feet and going hunting at 8 k feet there’s a correction factor.

[djpax13]

It would be interesting to compare charts from your normal at-home and at altitude.  It is not a serious problem and will subside when you return to your normal elevation.  Many people find Diamox (acetazolamide) can offset the effects of altitude including increased CA.  The CPAP makes this noticeable because you see the data, but if not for that, I bet you feel fine.

Thank you for the guidance. Now that I am home I was able to take a look at the data and yeah, last night definitely wasn't my best. Attached I have included last night's OSCAR and the previous night, which is more representative of how things have been going. No wonder I felt exhausted today, even after getting more sleep than usual!

[Sleeprider]

Next time at altitude, use a fixed pressure of 9.0 and EPR of 1. It should make a difference.