CPAPtalk.com

lazarus wrote: ↑

Thu Sep 07, 2023 10:10 am

Gfox began this thread with concerns about unresolved clear airway apneas, so a discussion of causative factors is appropriate. Miss Emerita pointed out that CO2 depletion is a cause. While that true enough, it doesn't explain how sensitive the breathing initiation process is to transitory changes in C02. We all have experienced post arousal apneas, wherein a deep breath is almost immediately succeeded by clear airway apnea. It is speculated that this deep breath (and it exhalation) blows off sufficient CO2 to temporarily suppress the normal rhythm, more specifically cause what is recorded as an clear airway apnea.
But is it really just a temporary CO2 depletion, and if so does CO2 blow-off occur with a single deep breath? Moreover, would a single deep breath cause an immediate (in a few seconds) cessation of breathing?
Perhaps, it might not be as simple as CO2 blow-off, perhaps there are other causative factors that Gfox ought to know/learn about to understand why he is still dealing with unresolved clear airway apneas.

You may frame dataq1 question as a quiz, but it deserves an answer, or a "I've no idea" so as to provide Gfox with understanding.

Tec5 wrote: ↑

Thu Sep 07, 2023 10:03 pm

dataq1 wrote: ↑

Thu Sep 07, 2023 5:13 pm

Doesn't matter either way, since they are completely normal occurances, despite the Tec5/dataq1 habit of repeatedly inserting an obsession with meaningless details inappropriately into multiple threads.

My choice is to foe/ignore you in all future threads because of what I consider to be disruptive/trolling behavior.

My choice.

Good day to you.

Physiologically normal apneic events

Central sleep apnea during sleep-wake transition

Up to 40% of healthy individuals may exhibit central apneas during sleep-wake transition. The central apneas occur during the period that chemoreceptors are resetting and instability of ventilation control occurs. They are usually brief and not associated with significant oxygen desaturation. The clinical significance of this entity is unknown. Once stable sleep is reached, normal individuals should not have more than 5 central apneas per hour of sleep.

Postarousal central apnea or postsigh central apnea

During a PSG review, central apneas are commonly seen following an arousal or after a sigh and are usually inconsequential. They are thought to be a result of Herring-Breuer reflex or hypocapnia induced by hyperventilation caused by a sigh or arousal.

--https://emedicine.medscape.com/article/ ... verview#a7

Underlining attribute added by me.

lazarus wrote: ↑

Thu Sep 07, 2023 10:34 pm

Thanks for the shout-out.

Perhaps cpapusers should be told right off that clear airway events (up to 5 per hour) is a "normal" expectation in sleep state.

As well, clear airway events observed in an OSCAR report should not be equated (or treated with equal import) with clear airway events observed during a PSG, particularity if the PSG has been edited by a Polysom Tech or Sleep specialist. So, for example, an OSCAR reported CA index of 10, may in fact be well within normal range.


Your citation to emedicine.medscape is interesting, and one thing caught my eye,

hypocapnia induced by hyperventilation

is that to suggest that hyperventilation (during sleep) is" normal" or "inconsequential"

lazarus wrote: ↑

Thu Sep 07, 2023 10:34 pm

My choice is to foe/ignore you in all future threads because of what I consider to be disruptive/trolling behavior.

Certainly it is your choice, for myself I will continue to ask questions to further MY knowledge and understanding as appropriate.
(BTW, it was Miss Emerita that brought up hypocapnia Gfox's thread - I just wanted to understand more of it's origins)

I notice that your sleep study 'lights out' was 11pm, and 'lights on' was 6:30am. Do you know what 'time range' your sleep clinic offers studies? I just had my first ever in-clinic sleep study and the latest they take in patients is 8pm, and my 'lights out' was 9pm. 'Lights on' was 4:45am, with a 'kick-out' time of 5am. As a night-owl, this was a near-impossible schedule for me. I'm wondering if I should seek alternative sleep clinics. Note - they told me on the phone that I could relax, watch TV, etc until, say, 10pm but my technician pretty much got me all wired up and then said 'goodnight' and turned out the lights at 9pm.

Miss Emerita wrote: ↑

Mon Sep 04, 2023 12:02 pm

...
During the baseline segment of the night, you clocked a little less than two hours of sleep, which makes the data less useful than they would be if you'd had longer. During any night, a two-hour segment may be unrepresentative of events during the entire night

My sleep study was a 'split' affair also - diagnostic and therapeutic in one night. My tech said she needed a minimum of 2 hours sleep during the diagnostic phase, then we could move on to the therapeutic phase. I'm guessing, if you fall asleep immediately they may gather more sleep data in phase 1, but if you are struggling to sleep, then they'll cut off the diagnostic phase once they have the 2 hours, and launch into the therapeutic phase. It sounds like the 2 hour minimum is somewhat standard.

Gfox wrote: ↑

Mon Sep 04, 2023 2:20 pm

...Yes, the sleep study was a bit of mess. I have a hard time sleeping in those conditions.

I absolutely hated my study! It was my first, so I had no idea what to expect. I brought my own pillow but not my own bedding; they had old-fashioned 'blankets and sheets', which I cannot sleep with (I have a duvet+duvet cover at home, with no loose sheets). I always get tangled up in loose sheets. There was a probe right behind each ear, which dug into the ear-lobe when I lay on my side; the room was colder than I'm used to, and there was a background 'hum' (presumably the building air con) all through the night. Also, I developed a dry throat, presumably due to constant air movement in the room. On top of all that, I had to get up to pee at least 4 times, despite having made a point of not drinking much. In the end, the tech said she got the minimum 2 hours but there wasn't enough time to do the therapeutic phase, so now I need to see if they'll schedule that for me. I guess next time, I'll be more prepared, and will bring my own bedding. How anyone can sleep with all those probes, tapes, tubes, all over their head and body is a mystery to me!

I don't think they gave me any options on the timing. But I suspect that they are all around 10pm Check-in time. I don't know what other sleep labs are doing --- this was my 3rd study by the way (1 at home, and 2 in lab). Lights out at 9pm would be a non-starter for me too

I have a bit of an update on my end. Since the pressure change suggestion came up in this forum, I have started to experiment with this again. First step here was changing the settings back to auto to see what the machine does come up with for me (with my now better set-up, being essentially leak free). Surprisingly, it *appears* to me that I might need a higher pressure to control my events, after analyzing the charts for the last couple of nights since I made the change. Per my sleep doctor's suggestion, I was running on a fixed pressure of 10 since December. Now, I have changed it to auto 7-15. The machine now provides peak pressure of 12-13cm but a median of only roughly 10. But more importantly, I do feel more rested, which is encouraging. However, here's the caveat:

My AHI still varies from 2.5 to 7+ depending on the night (with no significant changes in the sleep set-up, other than pressure settings). And there are a lot of centrals still popping up in there, but they *appear* to be arousal-related as per the breathing pattern the minutes / seconds beforehand. They do not look like true central events with the typical waxing and waning pattern.

I have posted the Oscar charts from last night below -- it would be great of you to comment on the following:
1. Would you agree that those look like arousals events (for the centrals)?
2. I do not see obvious treatment related reasons why I would wake up so frequently (and stop breathing) since the leaks are under control. Could this still be induced through the CPAP treatment itself? Or other reasons I should investigate?
3. Seeing those auto-settings now, would you change it back to a fixed value? If so, what makes sense? I am thinking trying 11 or even 12 to preemptively address all obstructive events.

Full night overview:
https://imgur.com/9wEG972

Cluster events overview:
https://imgur.com/ZcAvtrX

Event zoom in:
https://imgur.com/xbEFqlF

Event-free breathing:
https://imgur.com/9ggTh0X
 
Any other thoughts more than welcome, of course!
Thanks so much for your support.

Gfox wrote: ↑

Sun Sep 24, 2023 12:56 pm

feel more rested

Excellent! Let's put that in the win column.

Gfox wrote: ↑

Sun Sep 24, 2023 12:56 pm

centrals still popping up in there, but they *appear* to be arousal-related

Likely an indication of restless sleep (as you've mentioned in posts about moving a lot in your sleep), not a matter of treatment, so all the sleep-hygiene principles will likely do much more for your AHI in the long term than fiddling much more with treatment settings.

You have mentioned eating late and going to bed late, for example. What you eat, when you eat it, what meds you take, what time you take them, whether you have caffeine and when, whether you drink and when, what temperature your bedroom is, and on and on, all can have a profound effect on how restless your sleep is. Stress and worry can play a role. Whether you always go to bed at the same time and, especially, start your day at the same time deeply matter. Getting regular sustained exercise during the day is a biggie.

When restless sleep is the root cause of open-airway AHI, you need either to get at the root of the restless sleep or to ignore it. Because every time you roll over and change positions you are likely to shift sleep stages or have an arousal, enough to cause a pause in breathing. You can either ignore what that looks like in your home-machine reported numbers or you can work on your daytime habits and pre-sleep rituals.

Whatever the case, if you are feeling more rested, take the win. And if you rolled over in your sleep a lot the night before, don't worry about the fact that your home machine doesn't know better than to report that to you in your AHI numbers. Don't let that trick you into not focusing primarily on the other areas of life that improve sleep and health and the beauties of life itself.

I ask my wife to report when she notices leg movements from me. I can go weeks without them. But if I have them a few nights in a row, that will show up on my AHI. I don't change my machine settings for that, though. Why would I?

I wish you full success! But that often just means getting things as good as you can get them and then finding the joy in that.

Just a footnote to Lazarus:

"True" central apnea events don't necessarily exhibit a waxing and waning pattern.

The chart you posted shows only around five and a half hours with the machine, and the overview page you posted earlier shows a lot of short sessions, breaks in sessions, and variation in starting and stopping times. In line with Lazarus's emphasis on sleep hygiene, I warmly recommend that you really work on going to bed and getting up at the same time every day (including weekends) and using the machine all night. If the breaks are mostly for urinating, restrict fluid intake for at least three hours before bedtime, especially for coffee, tea, and alcohol. You're used to doing things differently, so this will take some planning and determination on your part. But if you try it for, say, a month, I think the chances are good you'll see improvement in your sleep.

Thank you both, Lazarus and Miss Emerita.

I do indeed have somewhat irregular sleep hours and have this now on my to-do list for improving sleep as well.

My bedtime hours vary roughly from 11pm to 1am with allowing for ~7h of sleep. Making this a bit more regular and allowing for more sleep should help with the hygiene aspect.

Luckily, my actual full awakenings (like bathroom breaks) are normally quite seldom and *typically* I keep the mask on the full night (thanks to the awesome Bleep not a huge deal). Most of the likely arousal events (around the centrals) are ones where I am not consciously aware of or can't remember (but likely due to tossing and turning). My current hypothesis is that those are likely not true centrals and are indeed a function of restless sleep vs. centrals causing the arousals.

Otherwise, I am already controlling a good chunk of the other sleep hygiene aspects like keeping the room very dark, cool and I wearing ear plugs to reduce any noise interference. If I am at a screen late at night, I do wear consistently blue light glasses. Likewise, eating late and alcohol are kept at a minimum. I try to do more workouts as well, which in past seemed to help as well.

The other open area are my T levels which had been low a few years ago and this could be the case now again -- test for that is outstanding but I would not be surprised if that plays a role. Low T seems to elevate cortisol levels that could contribute to my restless sleep.

Anyway, I am hopeful things will get better going forward! Thanks again for all your thoughts.

Gfox wrote: ↑

Mon Sep 25, 2023 12:57 pm

...

Regarding your centrals ... I recently went through a 5-week home trial with a CPAP, where centrals were high, and then had an in-lab sleep study, and the centrals were zero. My sleep doctor concluded the centrals were all 'Treatment emergent centrals' and is now lining me up for an ASV trial. I'm a newbie so take my words with a pinch of salt, but I think you mentioned the ASV path in one of your posts.

Steerpike58 wrote: ↑

Tue Sep 26, 2023 10:33 pm

Regarding your centrals ... I recently went through a 5-week home trial with a CPAP, where centrals were high, and then had an in-lab sleep study, and the centrals were zero. My sleep doctor concluded the centrals were all 'Treatment emergent centrals' and is now lining me up for an ASV trial. I'm a newbie so take my words with a pinch of salt, but I think you mentioned the ASV path in one of your posts.

Was that sleep study one without a CPAP?

ozij wrote: ↑

Wed Sep 27, 2023 3:46 am

Steerpike58 wrote: ↑

Tue Sep 26, 2023 10:33 pm

Regarding your centrals ... I recently went through a 5-week home trial with a CPAP, where centrals were high, and then had an in-lab sleep study, and the centrals were zero. My sleep doctor concluded the centrals were all 'Treatment emergent centrals' and is now lining me up for an ASV trial. I'm a newbie so take my words with a pinch of salt, but I think you mentioned the ASV path in one of your posts.

Was that sleep study one without a CPAP?

Yes; as I documented in detail elsewhere, I was supposed to have a 2-part test (one to measure 'natural sleep', the other to measure my performance with an ASV machine) but I only managed 2 hours of sleep out of the entire 8 hour process, so didn't get to 'phase 2'. I'm now waiting for them to re-schedule phase 2.

The initial 'at home' Watchpat study indicated 31 (unspecified) AHI events/hr. Over the 5 week trial, AHI dropped to circa 18, with OA/H being 4, and Centrals being 14.

Thanks, Steerpike58. That was my thinking too and the reason I started this thread. I do have mostly only central/clear airway events left in my CPAP machine data. They can be as low as ~2 events/h and up to ~7 events/h bringing the total AHI to something between 4-9 events/h for me. Most days I have an AHI of ~5/h, again with the majority being central/clear airway events.

Now, thanks to this forum and the input of various people, it became clearer to me that those centrals are most likely just "falsely flagged' events and in fact I likely only wake up during those periods (when turning and tossing) and in that process might just sigh for a moment causing the pauses. Those events are then flagged as centrals while awake, and the machine does not know the difference. Of course, the argument could be also the other way around that in fact the wakening events are caused by the centrals (which is the more unlikely explanation, I believe). In any case, for me the question then remains to why I would wake up that frequently at all (e.g., assuming that CA events correlate with me awaking at night). This means I would have had about 25 of those brief awakenings last night, according to my central count. I do only recall waking 1-2 times to fix my blanket, but not 25 or more times. I am working to improve my overall sleep hygiene especially around getting to bed at regular time and allowing for full 8 hours of sleep etc. to see if that helps.

Also changed my settings back to auto recently which helped a bit already (apparently, I need a bit of higher pressure for peak obstructive events), but the centrals still remain. I do feel better though in the mornings, but not as good as I experienced in those rare nights where I had 0-2 events in the past and I felt completely truly refreshed. If did not have those great nights on CPAP in the past, I probably would have given up the hunt for proper sleep a long time ago .

By the way, my last in-lab sleep test indicated 4 central events/h (during the untreated part of the night), which makes me still wonder if there is something funny going on with my sleep beyond the obstructive stuff. I discussed this with my sleep Dr last time around and she indicated that we might need to do another sleep study again, but I am not doing great during the in-lab sleep studies sleeping very poorly and fear that results might not be representative for my typical nights.

Since the wheels are moving so slowly, I am considering getting an ASV machine myself to just try it out. While I have a route to get my hands on one even without prescription, I am unsure whether this approach would lead to success even if I end up needing one since I would not have proper titration for such a machine (not even thinking of the counterindications regarding certain kinds of heart failure which one might want to rule out beforehand). I suppose the machine is bascially fire and forget like a regular ACPAP machine, but it seems getting used to one takes a while as well. Is there anybody out here who went this route in a similar situation and had success?

Gfox wrote: ↑

Wed Sep 27, 2023 10:39 am

. . . working to improve my overall sleep hygiene especially around getting to bed at regular time and allowing for full 8 hours of sleep etc. to see if that helps.

Another part of the sleep-hygiene factor can be considering whether or not to go two weeks or so completely off all caffeine and alcohol, to see how much doing that does or doesn't help with fixing restless sleep. Some of us develop sensitivities to those substances over time without realizing it. Not quite an allergy. Not quite a direct cause. But a personal-sensitivity factor that can be ruled out easily enough, although the withdrawal period can make sleep worse for a few nights.

I drink regular coffee every morning and occasionally have a drink or two containing alcohol, so I have nothing personal against those things. However, I also have friends who were absolutely amazed how well they slept after a few weeks of that experiment.

Some ended up staying off both substances once they realized how much better their life was without them; others slowly added them back in over time little by little and played with amounts until they found their balance. Yet others found that the relatively brief reset allowed them to go back to nearly the same amounts of both, and they just do the two-week-off thing once or twice a year.

I think this is only really an issue for people who develop the sensitivity. But I also believe we sometimes forget just how powerful and interactive those substances can be, especially for some.

As for self-titrating ASV, there have been mixed results with that:

https://www.google.com/search?q=self-ti ... aptalk.com