A poll--or answer in essay form

[mellabella]

I don't know if I used the poll option correctly or not (we'll see if it appears; I don't see it on preview), but I was curious to know when folks record most of their apneas occurring during the night, if you've got a data-capable machine.

[tuna]

For me it varies from night to night..

[kteague]

Mine are scattered and so very few. AHI is usually between 0.0 to 1.3 and AI is 0.0 to .6 for the last year or more. No pattern as I've seen. Try to parallel them with leak rates, but often not the case.

[Slinky]

Mostly the first half to one third of the night. Even when I have 0.0 AIs you can see on the graphs the lines smooth out during the night w/the least amount of activity and more mild activity that last one half to one third of the night.

I have attributed that to the Spiriva inhaler I take shortly before bedtime taking 4-5 hours to show any effect on my breathing. Mebbe, mebbe not. Just my theory as to the reason for it.

[Velbor]

Here is a copy of my spreadsheet data, covering 20 nights:



Over 80% of my apneas occur during the first half of the night, before 4am. The highest concentration is between 1 and 2am.

Note that these data are on AutoPAP at 6 to 12; some may feel that these settings are too far apart, and may explain my relatively high, and widely varying, AI figures. Perhaps. Or not. I am currently collecting data at a narrower range of pressure settings, which to date look largely the same, but it is too early to draw conclusions. Note also that these data are with an Activa mask and taped mouth. I am also currently collecting data with an UMFF mask, and the data look markedly different, but again it is too early to draw conclusions.

Finally, there are reasons for some to conclude that I am a rather abnormal case. Well!!!

Velbor

[mellabella]

I ask because I'm noticing some clustering with mine. I don't know how much of the clustering that occurs towards the end of the night has to do with the longer REM periods in the final hours of sleep, and how much of it has to do with hitting the snooze button and lying there half awake (I checked the archives, and folks have mentioned you get higher AHIs if you're hosed up while awake). I'm going to try to take the card out on first awakening tomorrow night and see if that makes a difference.

Even taking that into account, I still have seen some clustering that seems to happen every 90 minutes or so, with the heaviest towards the beginning of the recording session, and then in the last few hours of sleep.

[Slinky]

Don't "they" say that we go thru a full cycle of sleep about every 90 minutes to two hours? And wouldn't that put us in REM about every 90 minutes to 2 hours? Assuming we were somewhere near "normal" w/our sleep cycles? I never paid real close attention to the sleep cycle information. I sleep or I don't. I feel rested or I don't. Tsk, tsk. I suppose I should pay more attention to such info.

Oh, yeah! and don't we normall (supposedly) experience deeper sleep in the early morning hours?? I don't know, that's why I'm asking. Seems to me in the dim recesses of my beady little brain I remember reading that somewhere. But what do I know?

[Goofproof]

Here is a copy of my spreadsheet data, covering 20 nights:



Over 80% of my apneas occur during the first half of the night, before 4am. The highest concentration is between 1 and 2am.

Note that these data are on AutoPAP at 6 to 12; some may feel that these settings are too far apart, and may explain my relatively high, and widely varying, AI figures. Perhaps. Or not. I am currently collecting data at a narrower range of pressure settings, which to date look largely the same, but it is too early to draw conclusions. Note also that these data are with an Activa mask and taped mouth. I am also currently collecting data with an UMFF mask, and the data look markedly different, but again it is too early to draw conclusions.

Finally, there are reasons for some to conclude that I am a rather abnormal case. Well!!!

Velbor

I can see why they are so bad at the early times, the way your APAP is set it doesn't have time to treat your apneas. raising you lower number to 8 or 9 would probably give better results. Jim

[mellabella]

Don't "they" say that we go thru a full cycle of sleep about every 90 minutes to two hours? And wouldn't that put us in REM about every 90 minutes to 2 hours? Assuming we were somewhere near "normal" w/our sleep cycles? I never paid real close attention to the sleep cycle information. I sleep or I don't. I feel rested or I don't. Tsk, tsk. I suppose I should pay more attention to such info.

Oh, yeah! and don't we normall (supposedly) experience deeper sleep in the early morning hours?? I don't know, that's why I'm asking. Seems to me in the dim recesses of my beady little brain I remember reading that somewhere. But what do I know?

You should give your "beady little brain" more credit: I've heard that both of those are true as well, which is why I'm curious about whether or not folks are seeing that reflected in their data.

[Slinky]

Well, I'm confident of the stuff I've personally encountered and take an interest in and bone up on, but no where near so confident of the information I encounter that doesn't particularly interest or pertain to me at the time that hangs around as dim memories not necessarily properly "filed" in the dimmer recesses of my old brain's "file cabinet". (The old "information overload syndrome" you know?)

[Velbor]

I can see why they are so bad at the early times, the way your APAP is set it doesn't have time to treat your apneas. raising you lower number to 8 or 9 would probably give better results. Jim

Well, I hoped that I had put enough scarecrows into my post to ward off responses of this nature. But nothing scares Jim!

ASSUMING that the thesis of "inadequate time to treat" with a "low" minimum is correct, it is still not applicable to explaining this data. If it were true, it might explain the "first few" apneas in a cluster (and yes, when I have apneas, they are typically "clustered", however that may be defined). But that is not relevant to explaining an excess of apneas early in the night. The minimum pressure setting is the same ALL night. Median pressure for this dataset runs at about 9.2; 95th centile at about 11.

But while it sounds reasonable on the surface, I have not seen evidence to support the "inadequate time to treat" paradigm. As I mentioned, I am currently collecting data at a higher minimum and narrower range, and preliminary review shows very little difference in efficacy. But more to the point, as I have mentioned elsewhere ( viewtopic.php?p=288379#288379 ), the ResMed Autos are capable of rise rates of at least 1.0cm/min. The response time is so fast that a "low" minimum would appear to have little clinical relevance.

Thanks in any case, Jim!!

[Slinky]

Well, one thing I've always thought of, Velbor, is that when we first lay down to sleep and go to sleep our breathing isn't as relaxed as it becomes later and later in the night as well go into deeper sleep. But maybe that's because that's the way my breathing seems to be. More shallow, more relaxed, more consistent. Its really obvious w/the oximeter graphs.