Sleeping on the Back, Risks of Increasing Pressure

[anacond]

Hi all,

I'm new to CPAPtalk.com, and I've had a Philips Respironics DreamStation with a ResMed AirFit F20 L mask for about six months now. The mask fits rather well, if I fasten it tightly. In the first couple of months, I almost always slept on the side, with pretty low pressure bounds (Min 8, Max 12 cmH2O). I usually felt much better than without the CPAP machine. All the while, my caretaker detected Cheyne-Stokes breathing patterns and central apneas in my stats. Gradually, I began developing back pain, even though I'm going to the gym doing back exercises quite regularly. This forced me to change to a supine sleeping position, lying on the back. I left the settings as before, and of course, my sleep worsened. I had to yawn a lot and was very tired. So I went to the sleep center, and my caretaker would let me increase the max pressure to 14 cmH2O and turn on C-flex level 2. However, I feel this isn't enough. My 90% value is very close to, or at, 14.0 cmH2O. Because my caretaker detected Cheyne-Stokes breathing patterns and central apneas, he is reluctant to let me increase the max pressure beyond 14, as this could worsen the central apneas. I would like to try increasing the maximum to a higher value. But I wouldn't want to do it without the caretaker's consent.

I feel that my central apneas simply come from the time before I had the CPAP machine. Back then, the obstructive apneas just told the brain to breathe less, and now that carried over to the time with the CPAP. Do you think that breathing exercises while awake are effective in combating central sleep apnea and increasing the feeling for one's breathing again? Do you think my device could handle a pressure range from 8 to 20 cmH2O well, or would the pressure end up being too high most of the time?

I'm attaching yesterday's sleep stats. Many thanks for your advice!

Screen Shot 2018-08-31 at 22.17.28.png (302 KiB) Viewed 10433 times

Screen Shot 2018-08-31 at 22.18.39.png (301.79 KiB) Viewed 10433 times

[Pugsy]

Welcome to the forum.

I would like to try increasing the maximum to a higher value. But I wouldn't want to do it without the caretaker's consent.

Well...you need more pressure but your doctor won't do it and you don't want to do it without the doctor's consent.
Either talk him into at least letting you try more pressure or get yourself beefed up to do it yourself....
I would "accidentally" change the max of 14 to 20 and just see what happens.
One night...I have my doubts as to whether or not those centrals are even related to pressure anyway.

They might be post arousal centrals...obstructive apnea stuff causes an arousal and then the central happens because of awake breathing after the arousal...and it's not real and wouldn't count.
Sometimes if you reduce the obstructive stuff the central stuff gets reduced because the centrals aren't real but instead they are a byproduct of arousals from sub optimal therapy.

You might want to take a crash course in figuring out if those centrals are real or not.
Watch all the videos here.
http://freecpapadvice.com/sleepyhead-free-software

[Not Fade]

Gradually, I began developing back pain, even though I'm going to the gym doing back exercises quite regularly.

Which exercises are you doing? Please be specific.

[palerider]

I would like to try increasing the maximum to a higher value. But I wouldn't want to do it without the caretaker's consent.

Then, what do you want us to do?

Either do it yourself, or stay at their (dubious) mercy.

Back then, the obstructive apneas just told the brain to breathe less,

That's not at all how it works.

Do you think that breathing exercises while awake are effective in combating central sleep apnea and increasing the feeling for one's breathing again?
No, exercising won't make a difference. Your central index is insignificant, at any rate.

Do you think my device could handle a pressure range from 8 to 20 cmH2O well, or would the pressure end up being too high most of the time?

12-20 would be a better setting for your needs, which are overwhelmingly obstructive.

[anacond]

Hi all,

thanks for your replies! I have just increased the maximum to 20 with C-Flex set to 2 and will tell you how it went. I can't really understand the doctor's reluctance to let me try a high setting for one or two nights. It's a good point that I don't actually have that many centrals. @Pugsy: Thanks for the link, I look forward to watching the videos soon.

My back training at the gym consists of one exercise, pushing back in sitting position.

[palerider]

Hi all,

thanks for your replies! I have just increased the maximum to 20 with C-Flex set to 2 and will tell you how it went. I can't really understand the doctor's reluctance to let me try a high setting for one or two nights. It's a good point that I don't actually have that many centrals. @Pugsy: Thanks for the link, I look forward to watching the videos soon.

My back training at the gym consists of one exercise, pushing back in sitting position.

The more flex you have, the more likely you are to have centrals... keep that in mind.

You need to raise your minimum too, that's very important setting.

[anacond]

Hi all,

so I had the first half night of sleep with 8-20 (the second half), and I felt quite rested, my head just felt like I have been hyperventilating a lot, and perhaps some stinging around my heart.

After having watched Pugsy's videos, I finally understand the connection between too much oxygen/too little CO2 in the blood and the body's reaction to it causing Cheyne-Stokes breathing/central apneas. That's also what my doctor meant. The funny thing is, I have the Cheyne-Stokes breathing patterns both with the min 8 max 14 setting and with the min 8 max 20 setting, both with C-Flex 2 enabled. So even 8-14 may be too high from that standpoint, but with me lying on the back, I need more pressure. With min 8 max 14, C-flex 2 helped my sleep subjectively, but with min 12 max 20, it may be counterproductive, so I will try turning it off for the next night, as suggested by palerider.

@Pugsy: I'm under the impression that the following aren't post-arousal central apneas, but rather they're induced by too much pressure coming from the CPAP machine, i.e. too much oxygen in the blood. Would you agree? (On the screenshots, the pressure is displayed wrongly because I had it set to 8-14 in the first half of the night, and 8-20 in the second half.)

So I'll try setting it to 12-20 without C-flex for the next night. Maybe that takes care of the hyperventilating/centrals.

Have a great day,

anacond

Cheyne-Stokes with pressure at 8-14.png (275.78 KiB) Viewed 10363 times

Cheyne-Stokes with pressure at 8-20.png (275.28 KiB) Viewed 10363 times

[Pugsy]

IMHO those respirations that you zoomed in on are not true Cheyne Stoke Respiration. There is some waxing and waning but they don't qualify for CSR in my opinion.
The machine didn't think they were either...no PB flag for those events.

The differences between just a waxing and waning of the air flow and real CSR can be quite subtle.
In my opinion..the ones you zoomed in on look more post arousal to me because of the big gulps of air involved during or preceding the waxing and waning.

BUT...even if these were the real deal...you aren't having a huge amount of it. See the last image below...that person is having a lot of real CSR.

This is what real CSR looks like

[anacond]

Many thanks for this clarification! I will ask my doc about both post-arousal central apneas, which don't count because I'm awake then, and show him your example of real CSR.

[palerider]

but rather they're induced by too much pressure coming from the CPAP machine, i.e. too much oxygen in the blood.

There's really no such thing as "too much oxygen in the blood", at least not with cpap.

Now, if you were in a hyperbaric oxygen chamber, then yes.

With cpap? no.

[anacond]

There's really no such thing as "too much oxygen in the blood", at least not with cpap.

Now, if you were in a hyperbaric oxygen chamber, then yes.

With cpap? no.

Thanks, I will put that to my doc, too!

[palerider]

There's really no such thing as "too much oxygen in the blood", at least not with cpap.

Now, if you were in a hyperbaric oxygen chamber, then yes.

With cpap? no.

Thanks, I will put that to my doc, too!

Oxygenation has very little to do with controlling respiration... You can get put in a low oxygen environment and just fade away to nothing without really noticing you're dying. Whereas, a little too much carbon dioxide in the blood will have you panting like a dog on a hot day.

Watch this guy, no 'respiratory distress' at all...

[anacond]

Oxygenation has very little to do with controlling respiration... You can get put in a low oxygen environment and just fade away to nothing without really noticing you're dying. Whereas, a little too much carbon dioxide in the blood will have you panting like a dog on a hot day.

Watch this guy, no 'respiratory distress' at all...

Very interesting, I watched it, he didn't even notice he was running out of oxygen or know what to do. But what, then, happens when one breathes "too much"/hyperventilates? Does that lower the CO2 and doesn't it create too many free radicals, which are connected to excessive oxygenation? Doesn't the lower CO2 then stop your breathing by way of the carotid bodies, except when you have a tendency to hyperventilate or a CPAP machine keeps pushing too much air in? Wouldn't that make a very high pressure unhealthy, as well?

[palerider]

Oxygenation has very little to do with controlling respiration... You can get put in a low oxygen environment and just fade away to nothing without really noticing you're dying. Whereas, a little too much carbon dioxide in the blood will have you panting like a dog on a hot day.

Watch this guy, no 'respiratory distress' at all...

Very interesting, I watched it, he didn't even notice he was running out of oxygen or know what to do. But what, then, happens when one breathes "too much"/hyperventilates? Does that lower the CO2 and doesn't it create too many free radicals, which are connected to excessive oxygenation? Doesn't the lower CO2 then stop your breathing by way of the carotid bodies, except when you have a tendency to hyperventilate or a CPAP machine keeps pushing too much air in? Wouldn't that make a very high pressure unhealthy, as well?

So much wrong.... :sigh:

When you hyperventilate, you're blowing off too much CO2, and you can get into alkalosis, because CO2 in the blood is acidic.

CO2 levels and oxygen levels aren't tied to each other. You can have high, or low SpO2 and high or low PaCO2.

The primary respiratory drive is driven by the level of CO2, ... or actually, acid, in the blood. I had acidosis a couple years ago, I was panting like a dog, I couldn't STOP panting, low CO2 depresses your automatic respiration, and that's why excessive ventilation from Bilevel machines can cause temporary central apneas.

CPAP machines NEVER 'push air in'. they provide a gentle pressure to hold your airway open so your lungs can pull air in, just like they do when you're awake.

And, NO, a "very high pressure" (a small fraction of one PSI, not even enough to blow up a balloon) is not unhealthy.

[anacond]

So much wrong.... :sigh:

When you hyperventilate, you're blowing off too much CO2, and you can get into alkalosis, because CO2 in the blood is acidic.

CO2 levels and oxygen levels aren't tied to each other. You can have high, or low SpO2 and high or low PaCO2.

The primary respiratory drive is driven by the level of CO2, ... or actually, acid, in the blood. I had acidosis a couple years ago, I was panting like a dog, I couldn't STOP panting, low CO2 depresses your automatic respiration, and that's why excessive ventilation from Bilevel machines can cause temporary central apneas.

CPAP machines NEVER 'push air in'. they provide a gentle pressure to hold your airway open so your lungs can pull air in, just like they do when you're awake.

And, NO, a "very high pressure" (a small fraction of one PSI, not even enough to blow up a balloon) is not unhealthy.

Oh, that was a very nice crash course, thanks! This feeds me with arguments to go up to 12-20 with my doctor. I have no idea why they're so reluctant to go higher. Do they want to keep us from having great sleep? I don't know.