Chinstraps and Centrals/Clear Airways

[startanew]

After about two months on APAP (5-20) with opus 360 pillows and a resmed chinstrap – I had been getting fairly good numbers AHI between 1-3 -- though most nights I was up 3-4 times.

This past week I decided to sleep without the chinstrap figuring I had learned to not mouth breathe. It is easier to mask up and more comfortable. Been a good news – bad news change. The good news is that I am getting to sleep sooner and having fewer major wake-ups 1-3 vs 3-4 most nights. And though it looks like leak rates increased a little – they are still pretty reasonable.

The bad news is that on 3 of 5 nights since I stopped using the chinstrap I’ve been getting big clusters of centrals/clear airways at least once a night. On good nights without the chinstrap I’ve been feeling better during the day, on the nights with clusters not quite so good (residual headaches and tiredness). Other settings (pressure) haven't changed.

Have other folks experienced an increase in CA’s or other events when transitioning off of a chin-strap. Could something else be going on?

Current plan is to stay off the chinstrap 3-4 more days to see if this subsides and if not go back to the chinstrap to see if it corrects this.

Some examples from the last few days with a closer look at one of the clusters

[JDS74]

That cluster at 4:18 looks awfully like Cheyne-Stokes respirations.

If that is what is going on, you need to discuss this with your doc.
He'll want to do some more studies to eliminate non-apnea causes.
It may be that you will have to get a different type machine.

[Sir NoddinOff]

That's almost textbook CSR. Something's wrong here. I suspect your mouth partially dropped open, however your leaks aren't terrible, hence partially open. For some reason your APAP machine barely responded to this event cluster tho your pressure range is set to 5-20cmH20. Talk to your sleep doctor and, BTW, I'd not throw away that chinstrap just yet.

[startanew]

Thanks...

I suspect I am doing some partial mouth breathing -- recall waking once or twice with air coming in the the side of my mouth.. wouldn't think it would be enough to prevent APAP from detecting and responding -- but then again...I am planning to go without the chin strap for a couple of days to build the baseline -- but I expect I will need to go back to it to better manage this. ..

One thing I am not clear on is whether "some" CSR and periodic breathing occurs in "normal" sleep associated with sleep stage transitions. Looking over the two months of data when I had the chinstrap on -- 2-3 nights a week I would have a 5 - 20 minute period of periodic breathing with hypotneas or centrals. Since most of the events are concentrated - my overall AHI for the night stayed pretty low. On most other nights there are also 5 - 30 minute periods waxing and waning breathing but no events. All of them typically 2-3 hours into a sleep session.

I am trying to figure out how to make the case for my doc who is part of a large managed care network since when I use the chinstrap my AHI <5 and the #'s look good on the surface. But my sleep still feels pretty interrupted (I have yet to get more than 4 hours a sleep session). And also to get a sense of how "concerned' I should be .

[robysue]

That's almost textbook CSR.

Without zooming in much more closely on that cluster centered around 3:00, it's impossible to tell if this is true CSR or a bunch of centrals NOT related to CSR or even just sleep/wake junk.

startanew, any chance one of your major wakes/restless periods was around 3:00??

Something's wrong here. I suspect your mouth partially dropped open, however your leaks aren't terrible, hence partially open.

There may be a bit of mouth breathing between 0:00 and 1:00, but it's not enough to worry about because the leaks are still pretty low. The leaks during the nasty cluster of centrals, however, is excellent for a PR machine at pressures of 5-7 cm H2O with a nasal pilllows mask like the Opuse 360: The expected leak for that mask at pressures of 5-7 cm is in the neighborhood of 20-30 L/min (as I recall) and the total leak graph stays below 24 L/min for almost the entire cluster of CAs and it's always below 30 L/min during that nasty cluster. In other words, during the cluster of CAs, there is NO unintentional leaking of any significance going on.

For some reason your APAP machine barely responded to this event cluster tho your pressure range is set to 5-20cmH20. Talk to your sleep doctor and, BTW, I'd not throw away that chinstrap just yet.

The APAP did NOT increase pressure during the cluster of centrals because centrals are NOT fixed by increasing the pressure since the airway is already open AND in some people, additional pressure can actually increase the number of centrals.

The two 1 cm increases in pressure shortly before 2:30 are in response to a cluster of OAs and Hs. On the PR machine, the machine will respond to a cluster of OAs and Hs by increasing the pressure by 1 cm and then waiting for at least minute or two to see the obstructive events stop. In this case, it appears that after the first 1 cm increase in pressure, there was a 5 minute (or more) gap before additional obstructive events happened. After the second 1 cm increase in pressure, there are no more obstructive events (and hence no additional pressure increases) until after the end of the nasty cluster of CAs.

The slow decrease in pressure during the central apneas is probably due to the search algorithm on the PR kicking in: The machine is testing whether or not there is an increase in flow limitations caused by a partially obstructed airway. The centrals are not caused by flow limitations; they're caused by the brain forgetting to send the signal to breath to the lungs and diaphragm.

[robysue]

I suspect I am doing some partial mouth breathing -- recall waking once or twice with air coming in the the side of my mouth.. wouldn't think it would be enough to prevent APAP from detecting and responding -- but then again...I am planning to go without the chin strap for a couple of days to build the baseline -- but I expect I will need to go back to it to better manage this. ..

Your leaks are well under control and your APAP is not having any real problem detecting your respirations. My guess is that you could do without the chinstrap from a leak point of view. Why wearing the chinstrap would reduce the number of centrals scored by your machine is an interesting question and worth investigating. I have no idea why that would be the case though. Maybe Sludge could comment?

One thing I am not clear on is whether "some" CSR and periodic breathing occurs in "normal" sleep associated with sleep stage transitions. Looking over the two months of data when I had the chinstrap on -- 2-3 nights a week I would have a 5 - 20 minute period of periodic breathing with hypotneas or centrals. Since most of the events are concentrated - my overall AHI for the night stayed pretty low. On most other nights there are also 5 - 30 minute periods waxing and waning breathing but no events. All of them typically 2-3 hours into a sleep session.

Have you got a history of heart disease? And how much of the periodic type breathing is actually flagged as PB by your System One?

I am trying to figure out how to make the case for my doc who is part of a large managed care network since when I use the chinstrap my AHI <5 and the #'s look good on the surface. But my sleep still feels pretty interrupted (I have yet to get more than 4 hours a sleep session). And also to get a sense of how "concerned' I should be .

First, what kind of a case are you trying to make for your doc? In other words, at this point, what do you want from the doctor? Help understanding whether those centrals are real and what to do about them? Help with fixing the continuing fragmented sleep?

I think what you need to do is focus on the obvious stuff:

1) Make sure the sleep doc knows that your sleep is still fragmented regardless of whether you wear a chin strap and that the fragmented sleep is leaving you with unresolved daytime symptoms of fatigue and/or sleepiness.

2) Make sure the doc has some Encore reports that show the high numbers of centrals being scored during certain periods of the night. If you have a history of heart disease, make sure the sleep doc knows about it and make sure the heart doc knows about the fact that your APAP is scoring lots of centrals and some PB.

[startanew]

You are right about the intended leak rates for the OPUS 360 cmH20 - 22 L/Min 7 - 26 L/min 9 is 30 L/min so there may be some unintended leakage - but it is minor

startanew, any chance one of your major wakes/restless periods was around 3:00??

Pretty sure I was asleep during the clusters ... don't know how restless I was. Though in general I am a somewhat restless -- high arousal sleeper.I am a side sleeper and will switch sides at least a couple times a session

While I usually give myself 15 - 45 minutes to fall asleep on the front end of a session before I get up -- the wakes at the end are usually -- more of the startled kind suggesting that I have been asleep. If I wake up and don't fall back to sleep in a few minutes - I get up. So i am pretty sure i was sleeping for most of the clusters.

Would it help to see data in more detail...And what would you look for to know the difference between "a bunch of centrals" and CSR. I don't want to cry wolf -- but there also seems to be a emerging pattern.

Have you got a history of heart disease? And how much of the periodic type breathing is actually flagged as PB by your System One?

No history of heart disease -- though my dad had issues ... See summary data -- Periodic Breathing most nights -- though in the .5-2% range. No idea if that is good bad or ? Though again it has ticked up without the chinstrap

I think what you need to do is focus on the obvious stuff:

1) Make sure the sleep doc knows that your sleep is still fragmented regardless of whether you wear a chin strap and that the fragmented sleep is leaving you with unresolved daytime symptoms of fatigue and/or sleepiness.

2) Make sure the doc has some Encore reports that show the high numbers of centrals being scored during certain periods of the night. If you have a history of heart disease, make sure the sleep doc knows about it and make sure the heart doc knows about the fact that your APAP is scoring lots of centrals and some PB.

Sound suggestions -- the challenge is that my sleep is very fragmented but my #'s look good.

BTW Robysue appreciate your notes on working with insomnia -- very helpful.

[robysue]

You are right about the intended leak rates for the OPUS 360 cmH20 - 22 L/Min 7 - 26 L/min 9 is 30 L/min so there may be some unintended leakage - but it is minor

Unless the leaks are waking you up, I'd say you don't need to worry about the leaks at this point.

startanew, any chance one of your major wakes/restless periods was around 3:00??

Pretty sure I was asleep during the clusters ... don't know how restless I was. Though in general I am a somewhat restless -- high arousal sleeper.I am a side sleeper and will switch sides at least a couple times a session

While I usually give myself 15 - 45 minutes to fall asleep on the front end of a session before I get up -- the wakes at the end are usually -- more of the startled kind suggesting that I have been asleep. If I wake up and don't fall back to sleep in a few minutes - I get up. So i am pretty sure i was sleeping for most of the clusters.

That increases the chances that these are real centrals and that you may have a problem with CompSA or Central SA rather than just plain old OSA. Did any of your sleep studies mention problems with centrals?

Would it help to see data in more detail...And what would you look for to know the difference between "a bunch of centrals" and CSR. I don't want to cry wolf -- but there also seems to be a emerging pattern.

Zooming in on that 30 minute cluster to the point where you can see the apneas in question would be useful. The thing that would help a knowledgeable person like Sludge figure out what's going on is the series of individual breaths. CSR involves a very pronounced and quite symmetric waning and waxing of the inhalations, often (but not always) with a central apnea or a hyponea scored at the nadir of the cycle. Usually the PR System One will have no trouble flagging real CSR, but not everything that the System One flags as periodic breathing is real CSR.

Have you got a history of heart disease? And how much of the periodic type breathing is actually flagged as PB by your System One?

No history of heart disease -- though my dad had issues ... See summary data -- Periodic Breathing most nights -- though in the .5-2% range. No idea if that is good bad or ? Though again it has ticked up without the chinstrap

I'm not a doctor, but I believe that normally they're not going to worry about a bit of PB in a patient who does not have heart disease. And if the PB is consistently below 2%, it's most likely not something to worry about. But if you're regularly having clusters of CAs scored that look like the one you posted earlier in this thread, then the CA clusters do seem like something to bring up with your sleep doc.

And again, it's interesting that there seems to be a correlation between the uptick in PB without the chinstrap.

Questions: When you don't use the chinstrap, do you think you sleep "better" in the sense of "deeper" sleep or more continuous sleep (in terms of wakes you remember)? Do you think you hit more REM sleep without the chinstrap?

BTW Robysue appreciate your notes on working with insomnia -- very helpful.

Thanks for the complement; I appreciate it.

[startanew]

Did any of your sleep studies mention problems with centrals?

Only had a home study - positional RDI supine 84, on my side ~ 11.. twice as many centrals as obstructives.

Zooming in on that 30 minute cluster to the point where you can see the apneas in question would be useful.

Here's the some wave forms from last night... Same pattern --- a few scattered around and then a big cluster 2-3 hours into the second session



Here is a close up of what things look like sleeping with no events -- and then the clusters...

Questions: When you don't use the chinstrap, do you think you sleep "better" in the sense of "deeper" sleep or more continuous sleep (in terms of wakes you remember)? Do you think you hit more REM sleep without the chinstrap?

Much better getting to sleep (and managing transitions when I do get up). Sleep seems a little deeper -- I suspect the increases in centrals could be related to actually getting to REM sleep...

That being said -- I will put the chinstrap on for 3-4 days next week to see if the central clusters go away. Can't help myself -- I research for a living....