Lab chases REM instead of AHI? Can we really self-manage?

[pjwalman]

Hmmm. If that's the case, then my sleep tech must have gotten pretty darned frustrated, poor thing! With the exception of 1.5 minutes of REM, I didn't get past Stage 1 and Stage 2, either. Yet I left titrated at 11, I think because I'd woken up and couldn't go back to sleep. Keeping me there any longer would have been likely futile. Guess they do what they can do when we are uncooperative and won't sleep well for them!

Peggy

[MikeSleeper]

You mentioned that before your sleep study, you thought you were sleeping great. What symptoms were you having that lead you to believe that you might have a sleep problem? Did you have alot of fatigue?
Did you have a sleep study based solely on your dentist telling you you had a small airway??
What improvements have you had since starting CPAP, that make you think you needed it?

It was solely due to the orthodontist's observation of a small airway, which made me think some small amount of fatigue I had during day could be related, so I wanted the test. Plus DDS told me untreated it could lead to heart attack... that really got me into the sleep study. Improvements since cpap are huge... I clearly forgot what it feels like to be rested. I realized the 'slight' fatigue was bigger than I thought, once I saw the other side of it. It's marvelous to feel this much rest now, all day. I just adapted to it before.

[mikenet]

I'm very interested in monitoring sleep architecture at home. There are a few projects(OpenEEG) and products(BrainMaster) that will give you a very small(only a few channels) EEG at home. There are a bunch of really cool applications(you can train classifiers that let you control programs with your thoughts, figure out what part of the screen you're looking at, etc). But I can't find any solid information about using them to monitor sleep architecture. People have run them throughout the night and made plots showing EEG data in the time domain or frequency domain, but I haven't seen anyone with an automatic classifier that could make something like a sleep architecture plot. I'm not sure how hard it would be to make one, as I really don't have any experience in the area. It might be a really simple software matter, a really complex matter of tuning heuristics, or a matter of not enough data in the few channels to reliably classify sleep stages automatically.

Has anyone ever been able to plot sleep architecture at home, with any equipment, EEG or otherwise?

(My recent post on the subject: viewtopic/t30400/Recording-Sleep-Archit ... -home.html)

[kteague]

My last two studies were on the machine and both said the results were suboptimal because I had not reached REM while supine. Theoretically if the events are resolved one will be more likely to reach REM. I wouldn't think that tech was saying they disregard the AHI, but that achieving REM is what they desire as events are likely to be at their greatest in REM (and while supine), and short of that the test isn't necessarily indicative of our true pressure needs. How could AHI be unimportant when it's what they base a diagnosis and successful titration on? I personally can't tell squat about if my treatment is working by how I feel because of other health issues contributing to me feeling bad. So the numbers are really the most reliable criteria I have to go on. If they look good, at least I'll know that piece of the puzzle is in place. Oh, my AHI is usually under 1.

[Rachael]

Mike, the more I think about it the more what your sleep lab is saying makes sense to me. Again with the: "Except what about the desaturation?" caveat. In the losing weight thread a study was quoted about sleep disruption reducing your ability to process sugar, all those studies where they take people without apnea and just wake them up, and their health goes to heck within a few days...

Maybe you should rent a pulse oxymeter and see what happens over night at the lower pressure. If you feel good, and your blood ox isn't too low... especially if you are having aerophagia.

[dankalm]

As I understand it, AHI is the combination of hypopnea and apnea. Of all of the posts that I've read-is there a ratio that is appropriate of hypopneas to apneas or are they all just bad? Does it matter?

[DreamStalker]

IMO, it is of primary concern that the O2 saturation be optimized and sleep architecture/REM should be a secondary goal. Hence, AHI is an important factor. What good is having good sleep architecture if you have a stroke or heart attack or some other significant health issues caused by apnea related O2 desaturations?

[MikeSleeper]

IMO, it is of primary concern that the O2 saturation be optimized and sleep architecture/REM should be a secondary goal. Hence, AHI is an important factor. What good is having good sleep architecture if you have a stroke or heart attack or some other significant health issues caused by apnea related O2 desaturations?

Right; I am assuming O2 sat optimization during titration is a given. But their decisions may not be AHI guided. We know in the lab they are monitoring 02 saturation separately, and can make a call on that independently from their AHI data. For example in my original study, even though my AHI/RDI scores put me in the severe OSA range, my max O2 drop was only down to 88% -- which is not that bad. So apparently AHI and O2 sat do not always drop at same ratio and one cannot predict how much O2 will drop based on an AHI score alone. Obviously it is directionally related, but apparently not definitively so. It is possible that my max O2 drop could be near normal with an AHI of 5 to 10 for example. Perhaps Apnea and Hypopnea event counts in that range just do not affect some people as much as others. The point being that when the tech says other measures (non-AHI) do a better job of determining my right therapy, he might be right.

That said, I will continue to monitor my AHI at home, and of course how I feel, because that's all I have in between sleep studies, and if AHI jumps way up (for example), clearly something is amiss. And I plan to research this topic more too, because we have seen people report on this forum (in this post) that their highly qualified docs DO apparently use AHI as the primary therapy guide. Never a simple answer!

[DreamStalker]

IMO, it is of primary concern that the O2 saturation be optimized and sleep architecture/REM should be a secondary goal. Hence, AHI is an important factor. What good is having good sleep architecture if you have a stroke or heart attack or some other significant health issues caused by apnea related O2 desaturations?

Right; I am assuming O2 sat optimization during titration is a given. But their decisions may not be AHI guided. We know in the lab they are monitoring 02 saturation separately, and can make a call on that independently from their AHI data. For example in my original study, even though my AHI/RDI scores put me in the severe OSA range, my max O2 drop was only down to 88% -- which is not that bad. So apparently AHI and O2 sat do not always drop at same ratio and one cannot predict how much O2 will drop based on an AHI score alone. Obviously it is directionally related, but apparently not definitively so. It is possible that my max O2 drop could be near normal with an AHI of 5 to 10 for example. Perhaps Apnea and Hypopnea event counts in that range just do not affect some people as much as others. The point being that when the tech says other measures (non-AHI) do a better job of determining my right therapy, he might be right.

That said, I will continue to monitor my AHI at home, and of course how I feel, because that's all I have in between sleep studies, and if AHI jumps way up (for example), clearly something is amiss. And I plan to research this topic more too, because we have seen people report on this forum (in this post) that their highly qualified docs DO apparently use AHI as the primary therapy guide. Never a simple answer!

True that ... O2 desats are perhaps more directly influenced by event durations (time in apnea/hypopnea) more than AHI. Myself, I was clocked at 99 apneas per hour plus a few extra hypops added to that for good measure but the 60% O2 desats were a real killer for me. The morning after my sleep lab study, the tech told me they got a bit worried about me ... and to think I lived like that for a dozen or more years without ever knowing what was happening to me. I'm sure the odds were stacked high against me to make it through very many more nights without getting treated.

You be right, everyone is different.