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Confused about AHI results
I've just finished 2 months on CPAP therapy, and things have settled down pretty well. Thanks very much to the many helpful suggestions and encouraging messages I've received here.

I've used my CPAP every night since starting therapy in early June, and i keep my mask on faithfully for 6-7 hours per night. I sleep on my side all night, usually. After a couple of rocky weeks at the beginning, my AHIs are now consistently under 5.0, usually between 3.0-4.5.

One thing puzzles me, however. Very often my 1st session, which is typically 4-5 hours, has dramatically better results than my shorter 2nd session and -- when I have more than 2 sessions -- my even shorter 3rd session.

Most of my AHI events comprise CAs, with very few hypopneas, and even fewer, if any, OSAs and RERAs. What happens is that I frequently experience a disproportionate number of closely-bunched CAs in the early morning after I've gotten up to use the bathroom and then go back to bed. For example, attached is a Sleepyhead screenshot of last night, showing the difference in results between my 1st session (5 hr 20 min) and my 2nd session (27 min). The AHI for my 1st session was 1.90, but with the 27 min 2nd session factored in, the AHI jumps to 3.90, twice what it was previously. The cause was 1 hypopnea and a cluster of 10 CAs in the short 2nd session.

This pattern is very common for me -- good therapy results for most of the night, then a short period in early morning with lots of CAs, resulting in a passable, but decidedly mediocre, overall AHI result.

Any thoughts on what's going on here, and what, if anything, I can do about it?

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Here's a better link for the image: http://screencast.com/t/t7K0QU9tu3iH
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(08-10-2015, 03:26 PM)AndyB Wrote: What happens is that I frequently experience a disproportionate number of closely-bunched CAs in the early morning after I've gotten up to use the bathroom and then go back to bed.
Events scored while you're awake, are meaningless and can be discarded

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I'm asleep during these shorter early morning sessions, but undoubtedly I'm not sleeping deeply.
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Same here. That's when almost all of my centrals take place.
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I get the same type of thing only with a few OAs thrown in for good measure, if I am barely asleep or if I am drifting between being asleep and awake. I think it is just sleep-wake junk and should be disregarded.

Best Regards,


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Thanks for the replies -- I thought there might be more to it than just transition-time CAs, but I'm glad to get other opinions.
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The machine aren't accurate in reporting events while you're awake. I often run test sessions during the day while watching TV or reading and often get several OA's scored and my AHI is often reported as being above 10. All that when I know for an absolute fact that I never pause breathing for any 10 second intervals. It makes me wonder if the reports are all that accurate when sleeping. That may help justify why you are required to get a lab sleep test to get insurance to cover the cpap machine.

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[Image: 98vdy8.jpg]
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(08-11-2015, 10:48 AM)surferdude2 Wrote: https://www.dropbox.com/s/fktalfepdxfja7...s.jpg?dl=0

Did you zoom in on the flow rate for those events to see what type of flow disturbance was being detected? If not please do so.
I find it very interesting that you are not aware of any disturbances yet the machine senses something.

I now know that I skip breathing when I am awake but I did not become aware of it until I took up SCUBA diving (many years ago). Loud breathing is the only thing you hear and it takes a little bit more effort than regular breathing so it was easier to notice.
if you can't decide then you don't have enough data.
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