[Gen.Blather]

I’m scheduled for late next month. I advise you to take your own pillows.

According to the tech I spoke to, the new equipment is much lighter. Also, it doesn’t really matter how bad your sleep is, they’re monitoring oxygen use. If it drops below 89% for a large percentage of the time, they’ll wake you and train you to use a CPAP. Regardless of how rested you are, they’re looking for physical or neural interrupts to your breathing. They will either be there, regardless, or not.

[neverevergiveup]

Yes, the most important parameter is whether you desaturate (oxygen level drops) during sleep. In obstructive sleep apnea this happens because your airway is being compromised during sleep - variety of reasons, including from an anatomical issues, or sometimes from obstruction from excessive mucus (I.e. with bad allergies).

[ProtectOurFreedom]

Gen.Blather got it right. It took me forever to fall asleep and, when I finally did, it seemed like only a minute later they were waking me to put on a CPAP mask. They don't need much actual sleep time to determine is your blood oxygen is dropping to bad levels. It'll be a crummy night of sleep in a strange environment. There's no way around that and not much you can do to ease that. Maybe bring an airplane black sleep mask with you.

A few things to think about after you get your CPAP:

1. When I got my CPAP machine, I bought a recording oxygen sensor on my own dime so I could monitor my own blood oxygen levels (partial pressure of oxygen is called "SpO2"). It reports on the number of SpO2 drops during your sleep. I've been using CPAP about five years and still don't care for the mask. Sometimes I'll take it off in my sleep around 2 or 3 am. I can see clearly on the SpO2 traces with-CPAP and without-CPAP. My SpO2 gets more erratic without CPAP. I use a product called "O2Ring" from a company called "Wellue." The "Oura" ring is the more popular solution these days.
2. If you are interested in how you are doing, get the "OSCAR" software for your computer. Then you can import the data from your CPAP machine. It's a simple process -- use an SD Card in your CPAP machine, pull the card now and then, pop it into your computer, start OSCAR and import data. You will see all sorts of interesting things.
3. You can easily merge the data from O2Ring or Oura ring with the CPAP data in the OSCAR software. The CPAP machine does not measure your SpO2. The two together give a more complete picture of your sleep.
4. As G.B said, there are "physical or neural interrupts to your breathing." Physical is your airway collapsing. Neural is your brain not telling your lungs to breathe. I've tried lots of things to improve my sleep. The best are:
   • Quiet time an hour or two before bed. No screen time.
   • Magnesium supplement two hours before bed.
   • Lots of exercise, but early in the day. Too close to bed time is disruptive.
   • Lose weight. Keep an ideal body weight.
   • No alcohol. That's a huge sleep killer.
   • No caffeine or none six hours before bedtime.
   • If you suffer from airway collapse it could be because you are sleeping on your back. You can buy a device with backpack-like straps that keeps a tennis ball centered on your back. When you roll over onto your back, the ball forces you to roll onto your side. It's supposed to train you to be a side-sleeper.
5. I've worked with two sleep doctors. Neither was very good, IMO. They don't spend much time with you or provide much guidance. They seem to want to get you in and out quickly without understanding what's going on. I find the Apnea Board forum to be a great resource. Lots of people will help and guide you. I think the expertise and guidance available there is, frankly, better than I got from the two sleep docs.
6. Medications and supplements have have a big impact on sleep. Evaluate them carefully.