OSCAR Data - Low AHI but still not feeling great, and are these real OA events?

[Santino]

I'm a new CPAP user of about a month. I took a lofta test and had AHI of 7 but RDI of 17. 

On CPAP, so far my AHI is usually 2 or less, but my AHI doesn't always seem to correlate all that well with how I feel the next day. Two nights ago I had an AHI of .52 but felt like I didn't sleep that well at all. By contrast, last night I had an AHI of 1.68 but felt fairly well rested. In general, I haven't felt any eureka moment yet and I still feel like I'm not sleeping solidly through the night, perhaps because my body is getting used to CPAP. 

I am also concerned that part of the issue is I may still be experiencing a lot of RERAs that are not being effectively addressed. So far I have been slowly ramping up my minimum pressure in hopes of addressing this possible issue while keeping the max pressure relatively low due to fear of leaks and pressure swings waking me up.

I'd appreciate help in determining whether OAs that are flagged are in fact actually OAs. Most nights there are few OAs flagged, but others there are a fair handful, last night included. However when I look at the flow rate some of them look like I had an arousal BEFORE the flow rate dropped off, so it isn't clear to me they are actually OAs. The first attached image is an example. By contrast, the second attached image looks more like a legit OA? 

I'm also attaching a zoomed out image of last night. I can also add an image of the night prior (when I didn't feel well rested despite the lower AHI) if helpful. In addition to my specific question about the OAs, I'd appreciate any suggestions about possible pressure modifications or any other suggestions based on the data. Thanks!

           

[Phaleronic]

Welcome to the forum Santino, those are valid OA events. I'd need to see the whole chart zoomed in so I could scan it (SleepHQ lets us do that) to confirm if you have reras unflagged in there, but for now you need to raise your min pressure to 8cm and raise max pressure to 11cm, you can leave EPR on @ 3 for now.

[Santino]

Thanks! Good to know about the OAs. I can give those pressure settings a shot.

[Phaleronic]

Sure thing! Could you please try the new settings tonight before bed for 30 minutes or so to see how they feel?

[SeePak]

Welcome Santino.

I mostly agree with Phaleronic, adjust the min max.

However, I am seeing that your OA events are triggered around 5 and 6 cm pressure.

That is due to the EPR setting which is dropping from 8 or 9 cm DOWN to 5 or 6 cm !

Also, even though your machine increased the pressure when the flow limit, OA was seen, it was not until over 1 minute before you started breathing again !!??

I am thinking possible positional apnea maybe?
No pressure can undo a tightly closed airway due to chin tuck etc.

However, if positional is not the case, then i would think it would be imperative to keep that pressure from getting too low causing the OA in the first place !

so, reduce EPR to 1 or even off if you can get used to the pressure  and adjust min max as suggested.
CA events will come down too. That can also cause sleep disturbances for sure.

Phaleronic, do you agree?

[Santino]

Thank you both. I increased the minimum and maximum pressure for a few days but was having issues with leaks and general suspicion that the pressure changes were affecting my sleep. I also had aerophagia for a couple nights. So I have been trying fixed pressure, at 8.4 the last couple nights. I also tried lowering EPR to 2 last night but didn't want to lower it further (yet) due to the prior aerophagia.

In general, the pattern has continued that some nights I have little to no OAs the entire night, and other nights I have several OAs, some of which are quite long. It is common for the OAs to be somewhat clustered together. I have included three screenshots from last night: 1) full night overview; 2) beginning of OA sequence (is that an arousal preceding the first OA?); and 3) latter part of OA sequence, including what appear to me to be some subsequent unflagged breathing events.

           

Based on what I've read, this could indeed be positional apnea? I sleep on my side and have been trying to sleep primarily on my left side because I seem to have less leak issues than the right side, for whatever reason. I have just purchased a soft cervical collar and can give that a try once it arrives if you all think that might be the issue here.

Is another possibility that it is REM sleep-related?

Also, what should I make of the correlation between the leaks and the OAs?

Other than perhaps trying the cervical collar, I plan to gradually increase the pressure back up to see if that helps, perhaps to 9 tonight. I am not opposed to returning to APAP, but am generally inclined to try fixed for the time being.

Welcome your thoughts and any other suggestions. Thanks very much for your help.

[SeePak]

Collar will help eliminate positional, that will be good.

Still, you have a decent chart, in my view.

Those CA events tell me you are not getting optimum CO2, and that leads to less O2 out of lungs, into hemoglobin, and then into cells, including the brain.

That can be a lot of your fatigue, tiredness that you feel.

I would not raise the pressure.

I would actually suggest to lower it to 8 cm, but no EPR or EPR=1.

The aerophagia may be caused by breathing that gets all mixed up, and possibly you are low tolerance to CO2 which is very common!

Need to get a constant pressure going to really help understand what you are dealing with and go from there.

The EPR can easily upset your chemistry, in my view, and in many views out there.

Maybe if you really gotta have EPR, for now, try 8 cm constant pressure and EPR=1 

If those are positional OA events, you will be on your way.

And if they are OA events from too low a pressure, then raising the EPR will get you above that threshold.

[Santino]

Thanks very much. I can try to turn EPR to 1 or perhaps just have EPR on ramp only and see how that goes.

Is there any significance to the fact that the OAs and CAs seem to correlate with the higher leaks, or is that typical?

[SeePak]

Not sure if your machine reacts to leaks by increasing pressure I have to look into that others hear me have that answer it's always good to get rid of as many leaks as possible

[Santino]

Below is my data from last night, with fixed pressure of 8 and EPR of 1. My events numbers look better (though I've had other nights previously with better numbers), but I did experience some aerophagia again. My subjective feeling of restfulness feels about the same--not great. Part of the issue is that I was awake for awhile when I took my mask off around 3 AM.

I also had another very long OA (67 seconds), as shown in the second screenshot. Seems I get at least one of these long OA events most nights. I'm not sure if it is notable, but they often seem to be preceded by some irregular breathing. Also, given how long I'm not breathing, you'd think I might remember waking up gasping or something? But I have no recollection of these events.

I will plan to give the cervical collar a try next, I suppose.