Increased Clear airway apneas

[RRR]

For some reason I have had increased episodes of clear airway events and some Cheynes Stokes Respiration recently, usually In the early morning in the 60-90 minutes before getting up. My original home sleep study in 10/18 had a central apnea index 3.1, but it has been definitely more frequent. The clear airway index on Sleepyhead last year was 0.11 and most recently 0.86. I am a healthy 73 without cardiac, pulmonary, or neurologic disease and do not use opiates, sedatives, or drink much (a glass of wine or a beer once or twice per week).

The current settings on my Resmed Airsense 10 autoset are pressure 15-16 cm H2O with EPR of 2. I have previously determined I need an expiratory pressure of 13 to mostly eliminate obstructive episodes with occasional brief exceptions.

I am concerned that some of the clear airway episodes are up to 40 seconds long. I would appreciate suggestions as how to adjust my machine settings. I also wonder if I should consider purchasing a AirCurve ASV machine to prevent long clear airway apneas.
Thank you for suggestions,
Richard

PS: Happy Father's Day!

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[Julie]

Hi, I'm curious how you came to the min. and max pressure settings that you use... the min. is quite high and I wonder if there was some issue that prompted that setting.

You seem to know that regular C or Apap won't address clear airway events... but if I'm wrong, let us know.

[Pugsy]

First of all...are you for sure that those centrals clusters happened when you were asleep? They are very close to a known awake time where the machine was turned off and back on again. Is it possible you were in and out of sleep...light sleep and not sound sleep???

Go here and watch the videos so you can learn to identify asleep vs arousal/awake breathing flagged events.
http://freecpapadvice.com/sleepyhead-free-software

Can you zoom in on a section of the CSR flagged events so we can see the flow rate/ breathing pattern?
Zoom in so the graph shows about a 4 minute segment.

The only real change that you can make with settings that MIGHT help would be the EPR setting but lets first figure out if they are real events and need worrying about.

[RRR]

Thank you for your replies. A zoomed-in segment of the chart is attached.

I chose my minimum setting of 15 with EPR of 2 to give a mask pressure of at least 13 to prevent obstructive episodes. I chose the max pressure of 16 to keep it as low as possible for mask comfort and to minimize leaks.

Richard

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[Pugsy]

That's not real Cheyne Stokes Respiration. That's just a little Periodic Breathing of which CSR is but just one kind of periodic breathing.
I suspect the breathing is more a half awake kind of thing and means nothing other than not sound asleep.
Periodic Breathing is a waxing and waning of the air flow that lasts at least 2 minutes.

This is what real CSR looks like. There's a much more pronounced and very definitive waxing and waning of the breaths.



or if looking at the software we use...looks like this

[RRR]

Thanks Pugsy - do you think apnea from periodic breathing that lasts close to 40 seconds such as the attached example at 7:19 AM is a problem that needs to be corrected to avoid oxygen desaturation? I suppose I could wear an oximeter to see how low it goes. Do you think ASV would be helpful?

Thanks,
Richard

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[Pugsy]

If I saw a lot of 40 second anythings I might get more alarmed but a random one every now and then I wouldn't. I think the breathing prior to that flagged central looks more arousal related than asleep related anyway. While we can't normally or wouldn't normally hold our breath for 40 seconds without it being uncomfortable maybe there wasn't a total cessation of breathing during that time frame.
I can't see much of the flow rate after that particular central flag but I don't see a big recovery breath either so I assume the body wasn't experiencing the need to take a big breath for some reason to get more air.

If I saw it happen a lot then I might invest in one of those overnight recording pulse oximeters just to make sure things were okay in the oxygen level departments. I have my doubts as to whether even if we did hold our breath for 40 seconds it would make any difference at all. I have done it for 30 seconds and watched my O2 levels with a pulse ox and it never changed.

As for the ASV...yes, it would clean up the breathing but I don't think you technically need it unless you do find with the pulse ox that you have prolonged significant desats when this unstable breathing happens. You wouldn't qualify for ASV based on this data though.

I have seen real CSR happen late at night like this and we couldn't blame it on arousal or awake related breathing and no other times during the night. I had a chat with a sleep tech about it and he told me sometimes it does happen and no one really knows why. They don't qualify for ASV though.

Now if you can get your hands on an ASV and you wish to use it for your own peace of mind....it can be done and wouldn't hurt anything.
I used ASV for probably 3 years or so just because I wanted to try it and I found I really liked it. I had no problems with centrals but someone dared me and I took the dare and found I really liked it because it let me use a lot less pressure for the bulk of the night than I was using with regular apap. Anytime I can use less pressure I am a happy camper. So there are pros and cons with ASV...it's going to clean up your breathing and make it regular come hell or high water and how it does it some people find they don't like it.
I didn't care...I slept right through some big changes. It isn't always so easy to find a good ASV though and they aren't ever cheap when you do. Should you want to try it...I can help with the settings to get you started...you won't need what you are using now I am 99.9% certain of.

In the meantime the one thing you could try with this machine is turning EPR off or maybe a reduction to 1 might help.
Some people find that using bilevel pressures can actually trigger centrals. It's really the only setting with this machine that might help and there's no guarantee it will. It all depends on if you were really asleep when those centrals got flagged and IF (big if) bilevel played any part in creating the unstable breathing. EPR creates a bilevel pressure situation...any exhale relief does that...even regular cpap/apap machines. The difference between inhale and exhale is called pressure support.
I have a friend who uses the bilevel machine that offers more pressure support than you can get with EPR....she was having about 15 centrals per hour with PS of 4 but when we reduced the pressure support to 3 the centrals went away essentially. So sometimes just a 1 cm change in pressure support will make a marked difference.
Again...this all depends on what is causing the centrals and if a person is really asleep or not.

So it is something you could try that wouldn't cost you anything. Reduce to 1 or turn EPR off and if you can't fall asleep without EPR you can set it for "ramp only" and use the ramp feature and hopefully fall asleep before ramp ends.
It may or may not alter the number of your centrals in your clustering. It is worth trying if you can....it might be that something weird happens in those wee hours of the morning causing the unstable breathing and EPR along with it ends up with central apneas happening.
Remove that one component for the unstable breathing and maybe the centrals won't happen. It's a maybe...but a maybe worth looking in to.

It all depends on how much this bugs you (and I assume it bugs you or you wouldn't be asking about it) and how often it happens.

[Lifeisabeach]

I'm with Julie on this... an EPAP of 13 is quite high and you may be struggling to exhale against that. If you are worried about oxygen desaturation, well wouldn't a high EPAP level cause that? In fact, too high a pressure in EPAP and/or IPAP could be causing the clear airway events. I'm going through this myself and I don't want to say much more yet since I'm not comfortable giving specific advice in this regard and will be looking for the others here to take a look at my data once I have a couple more nights with my new settings, but it looks like my own excessive large leaks and clear airway events were the result of pressure settings well in excess of what my current condition requires.

[Pugsy]

If EPAP was the cause of the centrals he would be seeing centrals all night. 13 isn't really all that high in the grand scheme of things.

He may need the higher EPAP to prevent the airway collapse...I know people needing 18 EPAP to prevent the OAs and hyponeas and it doesn't always cause centrals.
I know people who get a truck load of centrals with as little as 5 cm.

A person needs what they need to keep the airway open...I know some people who start out on bilevel with EPAP of 20 and IPAP of 25...and there's a few people who have to use one of the machines that will go to 30 IPAP.

[Lifeisabeach]

If EPAP was the cause of the centrals he would be seeing centrals all night. 13 isn't really all that high in the grand scheme of things.

He may need the higher EPAP to prevent the airway collapse...I know people needing 18 EPAP to prevent the OAs and hyponeas and it doesn't always cause centrals.
I know people who get a truck load of centrals with as little as 5 cm.

A person needs what they need to keep the airway open...I know some people who start out on bilevel with EPAP of 20 and IPAP of 25...and there's a few people who have to use one of the machines that will go to 30 IPAP.

Wowza. I was started out on CPAP set to 22 and felt like I was suffocating and couldn't tolerate it for long. On my first followup, my PA said CPAP was a mistake at that level and they switched me out to a bilevel. But we're all built different after all, or we wouldn't need these in the first place. Thanks for the explanation.

[RRR]

Thanks Pugsy! I'll try turning the EPR off and see how it goes.

Richard

[RRR]

Last night was a good night with the EPR turned off - only one clear airway episode lasting 10 seconds. I don't know if it was just a coincidence, I'll see how it goes tonight.

Thank you Pugy!

Richard

[Pugsy]

Only time will tell. Could be a coincidence since you didn't have the central issue every night.
Will be an easy fix if it does work though...cheap and easy and relieve the stress of worrying about it....can't get better than that.

[RRR]

I just started using ASV two nights ago and so far have had elimination of long central apneas. My mask is more comfortable and there has been much less leaking at the lower average pressure throughout the night. My AHI was 0.8 the first night but I was disappointed it was 3.34 last night. Tracings from last night are posted. If anyone has suggestions as to how to adjust my settings it would be appreciated.

Thank you,
Richard

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[RRR]

I adjusted my settings last night as Pugsy recommended - increase EPAP to 9 and PS to 4. The results speak for themselves:

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Thanks Pugsy for your help - We are all very fortunate to have the benefit of your knowledge, experience, and dedication to helping all of us on the forum.

RR

PS: Happy July 4th weekend!