Cheyne Stokes?

[sosotired]

Greetings,

I'm new to APAP (two months). Well that's not totally true, I gave it a shot for 18 months back in 1995 with no real improvement. My brother (sleep apnea runs in my family) loves his CPAP and convinced me to give it another try so did a home sleep study which was enough to get me an Airsense 10 Autopap from the Colorado Sleep Institute. I wasn't impressed with the home study since the 02 meter showed constant 02 of 85 all night and no EEG, but it got me back on CPAP. On my original sleep study in 95 at National Jewish in Denver, I was diagnosed with Moderate Sleep Apnea. Very few Obstructive Apneas and lots of hypoapneas. Positional Apnea with more incidents on my back and during REM sleep. They didn't have the terms RERA ad UARS back then but I'm sure they would have applied. Back in 1995 I was skinny and didn't snore so the sleep tech was shocked that I had apnea. 

So far I have some positives. Morning headaches are mostly gone. Cervical Collar got my AHI below 2. Thanks for the tip. To deal with flow limitations, I bought a vpap auto and spent a few days tuning it. Very High trigger sensitivity helped a lot. I keep thinking I almost have it dialed in but never quite get that great night of sleep.

My biggest issue is periodic breathing. My flow rate waxes and wanes quite a bit. I'm at 5000 ft altitude (Boulder Colorado) so that may play a part . Also I was diagnosed with silent reflux in January of this year and placed on 40mg of prilosec per day. It worked and my chronic post nasal drip is gone. Post nasal drip was part of the reason, I gave up on CPAP back in the 90's. I've raised my bed 8 inches and I think that has helped a lot along with the prilosec and bicarbonate. However over the last week, I've weaned off the prilosec and bicarbonate since it might lead to alkadosis which can lead to waxing and waning breathing patters.

I had a really good night the night before last (0 AHI) and 0 flow limits with EPAP of 7 and PS of 3. I thought I had it totally dialed in. Then last night it all fell apart. Waxing and waning all night. Sure looks like CSR to me. Please take a look at the charts if you have time and give me your opinions. Is this CSR?  I know I slept on my back and I'm thinking I may have left my cervical collar too loose and chin tucked. Could chin tucking cause CSR? Should I make an appointment with my doctor?

Thanks in advance,

Dave

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[SarcasticDave94]

Let's see if you can give us a 2 minute zoom in on the Flow Rate at a suspected area to bring a breath by breath view. Others would have to weigh in at what's shown.

[sosotired]

Thanks Dave,

Here are some closeups showing individual breaths.

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[SarcasticDave94]

You will need to zoom in even more. Two minute level of zoom means there's 2 minutes of time spread across the timeline/OSCAR page. My limited knowledge doesn't see indications of other than what to me looks like a CA or central apnea. Are there known/diagnosed heart troubles?

[Sleeprider]

You don't need to zoom in any more, we can see you have periodic breathing that is likely related to your use of the VPAP at a higher altitude. It's not uncommon, and there are a few things we can try. First, drop pressure support from 3 to 2 an 1 progressively to see if that resolves the problem. Change the trigger sensitivity to high. If these mitigation measures don't work, Diamox (acetazolamide) may provide some relief, and is commonly used at higher altitude to slightly acidify the blood and treat central apnea and hypopnea. Another way of equalizing out respiration, is to add some rebreathed carbon dioxide. Enhanced Expiratory Rebreathing Space (EERS) is not in common use, but can relieve these symptoms. You are not at a level where you need an adaptive servo ventilator, but that is a very effective therapeutic approach to the periodic breathing and centrals. Let's not get ahead of ourselves. Start curtailing pressure support and let's see where that takes us.

[sosotired]

Thanks! How's this?

   

   

[Gideon]

Welcome to the forum.

This is NOT Cheyne Stokes.  It is Periodic breathing. It lacks heving Central Apneas at the nodes of the pattern,  Many are likely to be Central Hypopnea/Flow Limits lacking the duration/magnitude to be considered events.

This activity is IMHO Central in nature based on your CO2 levels.
Let's drop your PS to 1, so
Set PS = 1
We can always raise it after the fact.  
15 minute duration is about ideal to view periodic breathing,  though 2 minutes is best for evaluating individual breaths.

[sosotired]

Greetings,


I wanted to say thank you bonjour and Sleeprider for the advice. Reducing pressure support was the right answer.

Since my last update, I've been lowering Pressure Support every night and every night my periodic breathing gets better. From what I can see in my charts, I get a minor event or arousal and my flow rate overcompensates and starts oscillating between too much oxygen and too little oxygen (or maybe it's actually too much CO2 and too little CO2) until it wakes me up.  For me at least, it seems pressure support acts like an amplifier and increases the amplitude of the oscillations. It crates mountains out of mole hills. No wonder, I haven't been able to sleep for the last two months.

Last night I got down to zero pressure support and got the best night's sleep since I started therapy. It was so nice to see a minor event/arousal in my flow rate happen and then magically clear up with a few seconds of recovery breathing instead of going into a wild cascade of oscillations that typically wakes me up. Although I still have a bit of oscillation in my flow rate, it's so minor, I doubt it's of much concern. Correct me if I'm wrong but I imagine minor oscillation is fairly common.

I don't know why I was so hung up on using pressure support. It's comfortable, but I don't really need it. I guess I had it in my head that I needed it to resolve my flow limitations. What I didn't realize was that in my case a lot of the flow limitations were exacerbated by if not generated by pressure support. At least what got flagged as flow limitations since the downside of an oscillation looks a lot like a flow limition and would often show up as a flow limitation on my chart.

As for EPAP, I had Min Pressure and Max pressure reined in between10 to 11 because big increases in EPAP also appear to send my flow rate into oscillations. Tonight, I'm going to try (10.5 to 11.5) since I got a few flow limitations. Nothing terrible but several instances of flat tops on inhalation.

I've got some more questions. Will EPAP alone, without pressure support get rid of flat topped inhalation flows? I've read the saying that "Pressure Support is for hypoapneas and flow limitations". Should I even care about the flat tops? In other words: When is good enough, good enough?

Also I noticed that the Resmed algorithm doesn't always recognize my flat top inspiration as flow limitations. I suppose since I slip into them so gradually.

Since one night does not make a trend, keep your fingers crossed for me that tonight goes as well as last night.

And thanks again for the recommendations.

Below are last nights graphs. First the big picture.

   

Then the detail charts showing flat inspiration.

   

   


Thanks again,

Dave

[Gideon]

To determine hypopneas the machine takes a moving average and compares the current to that average, so if you are having consistent hypopneas the system will not flag them. The Flow Limit Chart is a flatness index for ResMed and should be fairly immune to a moving average.

[sheepless]

"The Flow Limit Chart is a flatness index for ResMed and should be fairly immune to a moving average."

this is news to me. I've often read here that flags for flow limitations are based on comparison to some prior period of time, meaning that if I'm consistently flow limited the machine will not notice. has our understanding changed recently or have I been wrong all this time?