Need help analyzing Oscar: centrals

[FormerSnoreGremlin]

Hi Folks,

Thanks in advance for any help you can give. I've been on CPAP therapy since the beginning of December 2019 - Resmed Airsense 10 for her + humidifier with P10 nasal pillows. As you will see, during my sleep study, everything was either a central or hypopnea. I've linked the results. As of this week, I am still having some centrals that I would like to address. My doc has a policy that she will not make adjustments if AHI scores are below 5. Obviously I'm looking for a new doctor.

I understand that sometimes Resmed marks things as CA when they aren't centrals, but I'm not sophisticated enough to determine if that is what is happening in my case. I'm comfortable adjusting my own settings, and early on turned off the EPR and reset the range to start at 6 instead of 4. 

I'd appreciate any info you all can give. Please let me know if you need more images!

Thanks!

[sheepless]

"I understand that sometimes Resmed marks things as CA when they aren't centrals, but I'm not sophisticated enough to determine if that is what is happening in my case."

idk that these machines are infallible but it's safe to say that the only central events that are clearly discountable are those that occur while awake. that is, while falling asleep, waking up or rolling over in the middle of the night. the machine doesn't know if we're asleep or awake so we have to use our memory & some rules of thumb based on our experience. so for example, I'll ignore a ca in the first few minutes of a sleep session because I fall asleep quickly. similarly, after a while we learn what a roll over looks like in the flow rate and ignore the odd ca that occurs at the same time.

[FormerSnoreGremlin]

Thank you. How do I determine what "roll over" looks like?

[sheepless]

yeah, I was afraid you'd ask that. give me a while to find an example. others feel free if you can get to it faster than me. meanwhile, you'll usually see relatively isolated disordered breathing for a few seconds, often preceded by a larger inhale or three & followed by relatively even breaths probably declining in amplitude as we fall back to sleep. others may have a better answer.

[Sleeprider]

At 6 to 15 pressure, you are only varying between 6 and 8 cm actual pressure. There is not much going on to raise pressure other than some minor flow limitations. Your apnea are all being flagged as CA, and each of the three examples we see in the zoomed shot all three CA events are preceded by a sigh or larger breath. This is pretty typical. The larger breath often comes ahead of a shift in position, and of course skipping a breath after a sigh does not cause any desaturation or CO2 build up. It's normal.

I think you could experiment with EPR at 1 or 2, and it might calm the few flow limitations you have, and we can see whether it causes additional CA events. Overall this is nothing to be alarmed about, and it is just a brief, skipped breath, not central apnea.

[sleepyp]

The other thing causing 'false' centrals that I've noticed is the large breaths preceding it as Sleeprider stated, however instead of position shifting I've noticed that many of mine are from a RERA that the machine didn't pick up. I get some shallow breathing followed by some large recovery breaths. This raises minute vent very quickly, and then that in turn causes a central. These centrals tend to be longer than the 10 secs you see after a position change, more like 15 sec+
For me in my experimenting, I've found that raising minimum pressure helps with this type of undetected RERA followed by 'central' event, and this is against the normal advise for centrals. I've attached an image of what I'm talking about. My point is there seems to be many flavors of central and appropriate action depends on the flavor.


Thinking out loud.
When I started out I never thought it was going to be such a balancing act, and I've realised there is no way for a sleep professional to give every patient the time it takes to really understand their breathing patterns and optimise their treatment properly. I do also think that CPAP machines ought to a lot smarter than they are, they are literally generations of control system technology behind. In both sense, patients are being very poorly treated, like dentistry in the early 1900s.

[Geer1]

Is this 1.34 central apnea index representative of your average results, a good night or a bad night?

1.34 central apnea index isn't that bad especially considering your sleep study included centrals. Some centrals are naturally occurring and trying to chase 0 ahi is unrealistic. My central apnea index is around 0.75 on average and I had only a couple centrals during sleep study.

One thing I noticed is that some of your centrals are occurring as leaks end. It is probably the leak that is causing arousal and then the central occurs as you transition back to sleep. Figure out how to minimize leaks and you might get rid of a few more of these centrals.

I believe sometimes when you see a big breath followed by a central it is just like the equivalent of a yawn. I have recorded myself sleep and these types of centrals don't seem to significantly affect sleep. Neither do sleep transition centrals, the problem isn't the central in that case it is whatever has caused the arousal.

[FormerSnoreGremlin]

Thanks for the response. That would be a pretty average night. Appreciate the feedback!

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Interesting! Thank you!!

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Thank you! I'll try 1-2 EPR and see how it goes!!