I qualify the following response by saying that I am not a doctor, and that this response is from my own experience as the spouse of someone with sleep apnea who wears a CPAP, and from the "homework" we have both done concerning this condition (but not at altitude).

I'd be snoring, then just stop breathing for half a minute, gasp a little, then start breathing again. Not a real big deal.

30 seconds is a big deal, esp. if it happens regularly. If you're having 10- to 30-second episodes throughout any given night, then you should seriously consider having a sleep study done, Steve.

See the information contained here. It will take some time to read, but is well worth it.

My wife has sleep apnea and has been using a CPAP since last September. She had a sleep study done just before then. During the sleep study, if you have a certain number of apneas during I think it's a one-hour period, they will wake you up and put you on a CPAP machine for the rest of that night. This happened to my wife very early in during her overnight stay for the study.

The primary consideration with sleep apnea is the low oxygen level that occurs in your body each time you have an "apnea" (defined as 0-25% air intake for longer than 10 seconds). Given the primary importance of oxygen to the body, the cumulative consequences of a low oxygen level during the sleeping hours every night can be significant.

While I can't speak from personal experience concerning sleep apnea at higher altitudes (perhaps Ken may have something more authoritative he could add), given the lower overall amount of oxygen available at altitude (and I understand that it's the same oxygen/nitrogen ratio at any altitude), I would not be surprised if sleeping at altitude exacerbates any existing apnea episodes, absent the use of the CPAP at altitude. I don't have sleep apnea myself, but I know that when I sleep at altitude, I have the same experience many others have at altitude of flying up out of bed in the middle of the night every once in a while, gasping for air. I can only imagine what effect sleep apnea might produce in an already oxygen deprived sleeping-at-altitude environment. At the least, it would probably make for a restless and uncomfortable night; at the worst, it could probably exacerbate the already low oxygen levels caused by the sleep apnea condition itself.

As for the mouthpiece Steve mentioned, it may be useful in mild non-apnea snoring; but I doubt it would be of any real help with actual sleep apnea. The CPAP machine forces air into the airway to keep open the part of your airway that is obstructed (in Obstructive Sleep Apnea -- one of three kinds of sleep apnea). If the CPAP air pressure levels are set correctly for your individual needs, then the snoring and low oxygen levels caused by sleep apnea should resolve. A mouthpiece can only mechanically modify your jaw position; it cannot provide the added air pressure needed in true sleep apnea.

Since it helps him get the necessary rest, I'd drag the thing along for car-camping, but forget it on the trail.

Yes, although if I'm not mistaken, CPAP machines can be run on some kind of a battery operation for at least one night at a time (with recharging each day), if you have that kind of an accessory (I'm not sure whether or not that is standard equipment or optional).

If future generations are to remember us with gratitude rather than contempt, we must leave them more than the miracle of technology. We must leave them a glimpse of the world as it was in the beginning, not just after we got through with it.
- Lyndon Johnson, on signing the Wilderness Act into law (1964)