Causes of Unknown Apnoea events?

[Ratchick]

Here we go. 

1 hour (roughly) zoom

[attachment=32565]

10 minute zoom

[attachment=32566]

2 minute zoom

[attachment=32564]

FYI, never any snores etc associated with these parts of my sleep data.

This particular session I feel like I was sleeping pretty lightly - there were definitely odd moments where I was doing things (like rubbing my finger and thumb together, and at one point I touched my mask and then pretty much instantly was out again with my hand on my face ) and I have always been prone to parasomnias (sleep talking, sleepwalking, sitting up, looking around etc) so I guess it could have been some of that - but I definitely wasn't AWAKE awake, and for most of it I was very much sleeping. The second period of it that night, though, I was definitely not moving at all, so take that as you will.

[Geer1]

Probably rem sleep (or maybe a type of rem sleep) for a few reasons.

Central apnea is rare during rem sleep and doesn't appear present in that data.

It is common for your breathing to look rough and have an odd respiration rate, strange odd breaths, more flow limitation etc.

I get finger/hand movements (almost like I am playing a guitar sometimes). In my research some amount of finger movement is normal in phasic rem.

Each of the two examples has a few of these periods and they appear to be around 45 min to 1 hr.

If my assumption on this is correct then your rem sleep appears to be reduced and occurring at wider intervals then normal (usually around 90 minutes, yours appears to be hours). This might make sense because I could see your body spending more time in NREM trying to heal body and the damage being done by hypoxia (and potentially other health issues).

I think those periods are great examples that your SPO2 rate can be improved significantly with treatment for your central apnea. Your breathing during those periods does not look great (typical for rem sleep breathing to be worse then other times due to relaxation/paralysis of muscles) but is still some of your best breathing and SPO2.

[Ratchick]

That all makes sense.

Another thing I often see is that (if I'm not having a relatively bad night) I tend to have a period at the start of the night with fewer events (or at least, fewer full-on apneas, I usually still have a ton of flow restrictions and short almost-apneas)... so I'm guessing that as I get into N2 sleep, I start getting a few events but then when I finally drop down into N3 my events go crazy. This has definitely been my suspicion for a while (hence partly why I started recording myself while asleep). It also makes sense why I have far fewer events during an hour or two long nap, generally speaking than during the full night and why a very restless night usually means a relatively low AHI.

Unfortunately, until/unless someone performs a sleep study complete with EEG instead of just the smaller-scale home studies I've had, I won't know for sure.

But also the apneas aren't the whole story, for sure. When I look at how many "non-events" I have, which are clearly affecting my oxygen levels and no doubt also absolutely exhausting me, but they aren't "officially" counted. What is measured as an AHI of 3.14 over the first hour and a half of my sleep last night (i.e. 5 CAs) ends up as an event count of 21.36/hr if you also include the 25 large and 4 small flow restrictions as measured by OSCAR, plus a bunch of other not-quite-ten-second pauses in breathing that aren't tagged either by the ResMed algorithm or by OSCAR. Pretty much all of which were associated with a visible drop in oxygen. Never with anything showing on the FL chart. So even when my measured apneas are low, that doesn't always mean my breathing is effective.

[Geer1]

Probably the other way around. N3 usually has better quality breathing and you are probably only getting small quantities of it because of the CSA and arousals in N2 sleep. Why you don't have this issue during naps (or less severe) is kind of interesting though, any chance those naps are in a different position (chair etc)?

I just did a 2nd study last night and learned some more things, have to wait for full report though. I talked tech into using CPAP shortly into the study and it did help. She went from thinking I didn't need CPAP to realizing it helps avoid arousal (that she thought were bruxism arousal) and that I actually need as high as 12 cm pressure in rem sleep.

Your issue would probably be improved by ASV as it would treat all of those issues. The trick is beating doctors over the head enough to get one or breaking down and buying one.

[Ratchick]

I know that NORMALLY N3 has the better breathing... but N1 doesn't last for 1.5-2 hours normally, right? I mean I guess it could, though I don't generally feel in that drowsy-half awake state for that long. and then again REM is normally the worst and may well be my best, so...  I just wonder if, because my issues are central rather than obstructive, the deeper the sleep, the worse my body compensates, and the more events. I must admit, I'd love to find out for sure, but I do not fancy an overnight in hospital to do it.
 
Nope, naps and full nights are spent in the same bed, same pillow, same position, same amount of uprightness... And I've found absolutely no correlation between position and my centrals (though certain things do trigger me to have a few more obstructional events... however I'm talking maybe 2 or 3 OHAI max instead of 0-1 OAHI normally.

ASV is absolutely the way to go for me, and I am banging heads. I'm in the middle of collating literally every piece of data I have to send to them with summaries of the stats because I don't know how else to get them to actually treat this with any kind of urgency.

Glad to hear you got some better results from your sleep study, though. Hopefully that will lead to better treatment for you.

[Geer1]

If that short period of better breathing is right at the beginning of the night it could be N1. If it occurs a bit into sleep then I would think more likely N3. N2 is by far the most common sleep stage and in your specific case I would assume it is seen in higher than normal percentages. I would have to see more examples of that specific occurrence to help guess what stage of sleep it correlates with (or whatever other phenomona may be occurring).

If you send too much data they will just glance over it and ignore it. You have to figure out some way to be succinct and demand change. Something like as follows.

I have now tried APAP for 3 months as per your recommendations and the results are not satisfactory. My AHI averages x while on APAP and my SPO2 averages x with desaturations as low as x. My issue both before and during APAP use has always been central apnea and according to Resmed's own literature APAP is not recommended for treatment of central apnea. Please see the attached website and Resmed titration guide both specifying that ASV is the equipment indicated to treat central apnea (especially when it remains present during APAP use as mine has).

Although my apnea and oxygen levels have not been sufficiently treated the partial improvement has had affects on my overall health and I have noticed a clear correlation of worse health symptoms after bad nights of apnea and low oxygen levels. I believe treating this apnea will provide substantial improvements to my health and I request immediate assistance in treating this health issue by either trialing ASV or having an overnight titration sleep study including ASV to see if it does indeed stabilize my sleep disturbed breathing as the literature supports it can.

I look forward to your response on how we can proceed with one of these next steps as soon as possible.

[Ratchick]

Yep, that's pretty much what I've said. Many times. I'm hoping by collating everything so I can send them a comprehensive list of how much time in the last two months I've spent with sats under 90/88/85/80/70% then I can scare the ever-loving crap out of them the same way it scared me to see a 92-second apnea right on the tail of two 60 second ones and the corresponding effects on my SpO2.

I went and took screenshots of a fairly "standard" looking chart (with and without the FRs flagged). Have at it. You can tell the first 20 or so mins are me waiting to fall asleep.

+FRs

[attachment=32610]

-FRs

[attachment=32611]

[Geer1]

I am interested to see what tidal volume and minute ventilation charts also look like (replace mask pressure and flow limit temporarily) to see if there are any ties between TV/MV and the two lower SPO2 periods that there appear to be fewer apnea during.

I believe you said you have obstructive apnea at lower pressures. I would be curious to see an example of that as well.

Edit: Without FR, too cluttered with them.

[DaveL]

Ratchick I hope you are able to get an ASV soon.
I'm humbled seeing your charts.
I appreciate the time you spend here so much. I learn a lot from your posts.