Central Sleep Apneas (THought anyway)

feeling_better wrote:I have been meaning to make a post about this for a few days, but have been very busy. I had noticed that running in Auto mode with low and high pressure set at the same value, say 6cm, will yield more data from a Respironics M-series Auto machine, than when running in cpap mode with the same pressure. One of the extra items is the flow limitations. There may be other items but cannot recall it now.

Right...it will show flow limitations in auto mode but not in cpap mode. As far as I know, flow limitations is the only extra thing shown in auto mode.

feeling_better wrote:Regarding the original poster's problem: If he has centrals at all it is highly likely that an M-series in Auto mode will go into a run away condition to the highest pressure. This had happened to me at the beginning of cpap use for me 6 months ago.

I don't doubt that can happen for some people. But I don't think it would happen to most people...even if some centrals had shown up on their sleep study.

"If he has centrals at all" -- Even though Jcochran titled this topic "Central Sleep Apneas" it seems (so far) that centrals were not mentioned by his doctor. Jcochran explained later that his doctor said RERAs (Respiratory Effort Related Arousals) were numerous. Those words in the name ... "Respiratory Effort"...means those little thingies are obstructive (not central) in nature, as far as I know.

When starting this thread Jcochran wrote:The machine always runs at max pressure and wakes me up. It will not go back down.

So something in the Respironics' auto algorithm doesn't respond well to Jcochran's breathing and one has to limit the maximum in order to find out what is going on. A systematic fixed level self titration can be a great help towards finding out what is going on, and what is best.

O.

ozij wrote:

When starting this thread Jcochran wrote:The machine always runs at max pressure and wakes me up. It will not go back down.

So something in the Respironics' auto algorithm doesn't respond well to Jcochran's breathing and one has to limit the maximum in order to find out what is going on. A systematic fixed level self titration can be a great help towards finding out what is going on, and what is best.

O.

When starting this thread, I don't think Jcochran ever stated what range his autopap was set for. Jury's still out, in my opinion, as to whether the range settings were optimized in the first place. Nor do we know for sure exactly that was waking him up. Could have been something else (apneas sneaking through?) waking him, and it was only then that he became aware of the additional pressure the machine had gone up to while trying to play catch-up. That could sure be the case if the min had been set too low to start with. Or even if the max was set too low to handle things either. Who knows....

As for "will not go back down", we've seen a lot of people post about waking up, start watching the pressure and wonder why it doesn't move back down right away...after all, they're now awake and breathing normally, so why doesn't the auto's pressure drop down to the min right then? As we've learned, though, the machines don't know if we're awake or sleeping, and they are designed to not yo-yo the pressure up and down abruptly.

All that said, I'm really not arguing in favor of Jcochran using "autotitrating." I do think he should do as you suggested ozij -- start systematically using one pressure to see if he can find a single pressure that suits him. Or try to get a bilevel for comfort issues that just might be important to how well he sleeps.

His current machine set for auto and a range of pressures might indeed be misinterpreting his particular kind of sleep disordered breathing and be running the pressure up unnecessarily. But then again, it might be that he was having genuine events that were causing the pressure climbs. Hard to tell from what's missing so far about what ranges were being used. Or maybe I missed seeing them.

Hello all. Sorry, I've posted so many threads about all my troubles that I left the crucial info. out of this one. Ok, I was titrated to a pressure of 6cm. When the DME gave me my machine, she set the min to 6cm and max to 13cm "This should be good". I used the machine 4 or 5 days at that pressure. I was woke up every night by the maxed out pressure. It was definitely the pressure, nothing else. I never, and I mean never, wake up once I go to sleep until the alarm goes off. I lowered the pressure to 11cm max, tried it, still in runaway and waking me up. I posted on here and was advised to try straight cpap. Went to 6.5 and now 7cm, no more waking up, sleeping whole night through, but AHI stays above 5-6. Still feel like crap. Having car wrecks, etc.. I'll scan my original PSG, before and after CPAP and post. What pieces of info (RDI, oxygen desat., Sleep onset, etc.) is most important when reading data? Thanks again.

feeling_better wrote: Regarding the original poster's problem: If he has centrals at all it is highly likely that an M-series in Auto mode will go into a run away condition to the highest pressure. This had happened to me at the beginning of cpap use for me 6 months ago. I had to lower the high pressure to about 6 before it became useful at all to me. Now I routinely run at about 4.5 and has AHI below 3 all the time. At pressure of about 7, my AHI could be 6-8, and my sleep is worse than without cpap!!

Snoredog wrote:Looking at that Encore report at 7 cm pressure, you need to increase pressure to 8.0 cm

Since we have no more data at this point, both suggestions seem equally valid to me.

O.

I'm sorry, I must have left something out. What other info do you need other than the PSG report?

I was referring to what we have at this point, without your scanned PSG report... sorry if that made you think something else was necessary. Did you insert it in a previous message? if you did, I missed that.

If you have the titration table on the PSG report, where they show how long they had you at each pressure, and what kinds of events you had there, that would help a lot.

O.

Jcochran wrote:Hello all. Sorry, I've posted so many threads about all my troubles that I left the crucial info. out of this one. Ok, I was titrated to a pressure of 6cm. When the DME gave me my machine, she set the min to 6cm and max to 13cm "This should be good". I used the machine 4 or 5 days at that pressure. I was woke up every night by the maxed out pressure. It was definitely the pressure, nothing else. I never, and I mean never, wake up once I go to sleep until the alarm goes off. I lowered the pressure to 11cm max, tried it, still in runaway and waking me up. I posted on here and was advised to try straight cpap. Went to 6.5 and now 7cm, no more waking up, sleeping whole night through, but AHI stays above 5-6. Still feel like crap. Having car wrecks, etc.. I'll scan my original PSG, before and after CPAP and post. What pieces of info (RDI, oxygen desat., Sleep onset, etc.) is most important when reading data? Thanks again.

Jcochran, for the majority of apnea sufferers, usually increasing the pressure solves many problems. So most suggestions you would get from the helpers here will be biased in that direction. But for a small percentage of them (especially if they have centrals induced by higher pressure), lowering the pressure would help. Purely based on my own experiments and results, I would suggest you try 5.5cm fixed and see how it goes. Always try for at least 4 or 5 nights with exactly the same trial settings to compensate for the possible significant night to night variations. If it is any better, try 5.0cm for another week, and so on.

I have another idea: if you can tolerate 4cm, a good method is to do an Auto with low=4cm high=6cm. This would possibly give you the distributions of your As and Hs at the pressures in between. This is how I finally arrived at my current pressure of 4.5 cm and AHI usually below 2. I was titrated for 6cm.

Also note that for some people, it is not only the higher pressure that sets up the Hs, but a change in pressure. So the above experiment with Auto still will result in changing pressures at night; so finally for fine tuning you need to try single pressures at 0.5 cm increments (or decrements )

feeling_better wrote: Jcochran, for the majority of apnea sufferers, usually increasing the pressure solves many problems. So most suggestions you would get from the helpers here will be biased in that direction. But for a small percentage of them (especially if they have centrals induced by higher pressure), lowering the pressure would help. Purely based on my own experiments and results, I would suggest you try 5.5cm fixed and see how it goes. Always try for at least 4 or 5 nights with exactly the same trial settings to compensate for the possible significant night to night variations. If it is any better, try 5.0cm for another week, and so on.

I have another idea: if you can tolerate 4cm, a good method is to do an Auto with low=4cm high=6cm. This would possibly give you the distributions of your As and Hs at the pressures in between. This is how I finally arrived at my current pressure of 4.5 cm and AHI usually below 2. I was titrated for 6cm.

Also note that for some people, it is not only the higher pressure that sets up the Hs, but a change in pressure. So the above experiment with Auto still will result in changing pressures at night; so finally for fine tuning you need to try single pressures at 0.5 cm increments (or decrements )

-There is NOTHING to indicate UARS.
-There is NOTHING to indicate Centrals.
At 7 cm pressure, he has vibratory snore, flow limitations and hypopnea, all traits of obstructive SDB.

So already he is above his titration pressure of 6 and the obstructive traits want to take him higher. There is nothing to indicate he needs a lower pressure. They gave him an autopap early into therapy? That means they blew his titration most likely from no REM or not much sleep.

He needs to open it up to 20 cm and see what is causing the pressure to supposedly runaway. It isn't centrals causing it to runaway, if it was the machine would throw up a NRAH flag and lock that circuit out for 15 minutes. Flow limitation and vibratory snore can drive the pressure all the way up to the maximum. Those events are easy for the machine to detect.

IF he has the Encore software, PUT UP one of the earlier reports where it was supposedly running away so we can look at it.

Snore. When I started this post, I was asking about centrals. I didn't really know what they were, but had heard my doctor mention them. My sleep study said that I suffered from Apneas, Hypopneas, and centrals. I went back to my doc after starting this thread and asked him about it, he told me I suffered from UARS. I am definitely not a doctor, and may have been wrong, but I trusted his professional opinion. I do know that my first PSG showed nothing, my second with some nasal sensor then showed the arousals. I also know that I am no better from my Cpap/Apap therapy, which is why I'm here. I could not tolerate my APAP set to a max of 13 and I tried for a week. I then tried 11 and could not tolerate it either. There is no way I'll ever tolerate 20cm. As far as not much sleep, I slept for over 7 hrs, as first onset of sleep was less than 3min from Lights out time. That is a long time for me. I fall asleep whenever an opportunity is there and can sometimes sleep so hard that I bite the heck out of my tongue to the point where it hurts for two days afterwards and never wake up. I'm here for help and will try anything, but really don't think 20cm is going to work. Here is last nights data: Let me know what you think. Thanks.

I've been playing with different pressures on straight CPAP and still can't get my AHI below 7

You've got you AHI below 7 now when you're on fixed 9. Stay there for a week.

O.

Ah, I totally missed this thread the first time around (thanks Den for referring to it).

I'm a bit confused about your comments that the P&B does not detect flow limitations in CPAP mode. I can just as easily track my FL's in CPAP mode as in APAP mode. That's in fact the only thing that correlated with my last 'downhill slide' - I was running just fine at 10.5cm for over a month and then I started feeling tired again, and the FL's had slightly increased.
What am I missing?

Edit: Here is a recent example from a night at 10.5cm fixed pressure CPAP with a million FL's: http://sleepecho.googlepages.com/oct11.jpg

Ohhh wait, do you mean the Hypopnea+FL line?? On the other hand, I thought that Runs = 3 consecutive FL's.