Better AHI but still centrals

[summer]

Happy New Year to everyone!

I'm still having problems with centrals, over the past few days my AHI has come down and has ranged from 5.4 to 6.8. When I posted last week my AHI was 9.2 with 8.67 centrals and the general consensus was to increase my min from 7.5 to 8 and to leave my max at 10.

However I decided to leave min 7.5 and reduce max to 9.5, and leave for a week, things started to get better when I noted that EPR was set to 0 and not "off", so I set EPR off. This could be coincidental, but my AHI's reduced, anyway last night my AHI was 6.8, centrals 5.70, I have attached a number of screen shots and I have a few questions;

1) I note that a number of the centrals are proceeded by flow limitations and slight reduction in flow and an increase in flow, then the central. Is this because there is a partial obstruction, which is causing erratic breathing that then affects co2 subsequently causing centrals?
2) I also note that during some of the centrals there is an increase in respiration, I do not understand this as there should not be any respiration during a central?
3) is possible that some of these centrals are obstructive in nature?






The pressure spends a lot of time above 9.00 and most of my events look to happening during REM sleep, I know that I need to increase the min, but it now looks like that I need to increase the max to get rid of variations in flow/respiration, is this correct?

Thanks you all

[Pugsy]

Is it possible that you were awake or semi awake during those times with large group of clusters?
Especially that last hour or so? It is normal to have "centrals" during sleep onset, sleep stage transition, turning over in bed and holding our breath and when we are semi awake. Also remember that the machine only measures one aspect of a central which is the air flow. It doesn't know if you are awake, in sleep transition, or even holding your breath when you turn over in bed. It can't determine thoracic effort either.

[summer]

Hi Pugsy,

I think you are right, some of them are transitional/awake,but it just seems an awful lot of centrals from 4.00 am onwards and I did not feel good when I got up. I felt very light headed with a mild headache, I suspect I had low s02 for part of that period, tonight I will up the min to 8.00 and see what happens.
Do think I should leave the max to 9.5?

[Pugsy]

tonight I will up the min to 8.00 and see what happens.
Do think I should leave the max to 9.5?

I sit here scratching my head trying to think which way would I go if this were me. It's obvious that the obstructive component is wanting to stay around 9 cm and narrowing the range with 8 min would be my first choice. More to limit the chance of pressure variations disrupting sleep than a desire to treat the obstructive component better because it is already well treated. While the 9.5 max even now with min of 7.5 really isn't much of a variation, I suppose it is enough variance to possibly cause some sleep disruption and maybe explain that last cluster. I am not so sure that last hour is the real deal. This is one of those times that I think an over night pulse ox to confirm or not the oxygen levels for that time frame would be a real plus to have. We can feel crappy from poor sleep or sleep fragmentation just like we feel crappy from low O2. I speak from personal experience on that part.

Your Central index dropped with the drop in maximum. Not a huge drop but a drop and if you didn't have that one large cluster of centrals flagged on this report then your report would be quite acceptable.
I don't think these centrals (if they are the real deal) are really pressure induced in the sense that we really worry about because if they were we would see them all night long and not have those periods of nothing going on. Wonder if they are "therapy induced" as in perhaps it is REM related and pressure combined with REM events is disruptive to sleep??

I think when in doubt about what to do.....just make one change at a time so that potential changes can be easily related to a change. At this point I don't see the need for more max...If your Hyponeas or Obstructive apneas were much higher...yeah more max but that part is well treated. It is only the centrals (if they are the real deal) which are muddying up things and we don't treat the centrals with pressure. If there is some flow limitation involved to a minimal level..perhaps the minimum increase will better control that aspect. So I would only change the minimum again if I was going to change something.

You know if it were me....on my list of things to try...would be a straight cpap pressure on the off chance that pressure variations however small on APAP were disruptive. Probably at 8.5 or 9 if it were me and I was trying different things.

[MaxDarkside]

Your machine looks to be bouncing up against the set upper pressure limit (9.5) a majority of the time, suggesting it would like to raise pressure higher to resolve issues, but cannot. I prefer to have my machine freely operating between limits, never hitting them during the night. In a recent chart of mine (viewtopic/t72661/Is-this-REM-sleep.html) you can see my S9 is modulating back and forth freely between my 5-15 limits, rarely touching them. I start at 5 just for comfort dozing off. Just my view, not medical advice of any sort

[Mary Z]

From what I understand the S9 records "clear airway" events which it is unable to differentiate from central apneas. CA events could not be obstructive in nature due to the definition of the event. To measure centrals you really need an in lab test with the EEG leads and pressure belts.

[MaxDarkside]

Since the proportion of centrals is so high, I would think a doctor consult, and perhaps another study, would be wise to find out if they are in fact centrals, what the cause is and if some other mode of treatment is indicated.

[Pugsy]

Your machine looks to be bouncing up against the set upper pressure limit (9.5) a majority of the time, suggesting it would like to raise pressure higher to resolve issues, but cannot.

When she had the max near 12 she had more centrals.
If the obstructive component of her AHI was much higher than the 1.16 Hyponea index then I would agree that perhaps the max needs to be increased but it just isn't there. Or if she didn't have these centrals the max wouldn't concern me. We don't know what issues the machine is sensing to keep the pressure pegged out at the max. Is it perhaps some flow limitations? Quite possible.

While my gut tells me that these "centrals" aren't the kind of centrals that we would normally worry about, but Summer does complain of feeling like crap after that large cluster so we can't completely rule out the possibility that they are real and might be a problem if we let the machine go higher with pressure trying to fix whatever is driving the pressure up.

If the centrals weren't a factor....heck...open the range and let's see where it wants to go and see what happens. If the obstructive side of things were not well controlled at this range....open the range.

There comes a time when centrals are a concern that we simply have to make a compromise. Keep the pressure low enough to limit centrals (if they happen to be related to pressure) and yet accept the fact that the pressure needed for addressing all the obstructive needs might not be quite perfect.

At this point in time we don't know for sure if those centrals are an indication of a problem or just a fluke notation from semi awake status fooling the machine (which my first instinct says). I prefer to err on the side of caution whenever I don't know for sure what is going on.

Also, some people like yourself and myself do very well with a wide APAP range. Others don't. Whenever see APAP and centrals in this number....I prefer to back off and go very slow. Hurts nothing to use an extra measure of caution.

And yes, a discussion with doctor about these "centrals" would surely be warranted if they are consistently present like this and a person feels like crap and couldn't remember if they happened to be awake or semi awake during this time frame. If it doesn't happen all the time.....then perhaps a fluke that we can blame on the aliens. I have had reports just like this one and they are rare but they do happen from time to time. This is why I don't base changes in pressure on a single report.

Edit to add: BTW I didn't mean to pick on your response. Normally I would agree with what you said.
I just wanted to explain the method in my madness when I don't do something I would normally do.
My very first response to Summer a while back was to increase the max It has her mention of a slight reduction in centrals with lower max that has caused me to re-evaluate that idea.

[summer]

Hi Pugsy, MaxDarKside,

Its a fine balancing act!, a few day ago I got a 5.4 AHI, central was 3.39, Hyp 1.70, OSA 0.52 all on the same parameters as last night (min 7.6, max 9.4), although I had more leaks!!!.
The machine seems to want to go higher, I do feel that I need to up the max, the reason is that in the graphs that I posted there are examples were the flow limitations are not fully controlled and they seem to be causing slight constriction on the flow and respiration to alter. I wonder whether is like a ripple in a pond effect, were the breathing rhythm is changes( hyperventilation) causing changes in co2 that give rise to centrals, but taking on board Pugsy's point that many of them may also be transitional etc.

Have a look at the two graphs that I posted earlier showing a Central apneas in detail. I think I need to take it slowly in APAP mode, a min 8 or should I go straight to 9 min?. The S9 increments up or down in increments 0.2

Mary Z, rescan is recording the events as Central apneas rather than Clear airway.

BTW I should have continued the original post to give every one some background, brain fog!!

[MaxDarkside]

BTW I didn't mean to pick on your response. Normally I would agree with what you said.

No worries. You are right and I after I thought a bit, I made the additional post that Summer probably should talk to the doctor about the centrals maybe to see if they are real. I had only one central in my sleep study and then my S9 started reporting more and more and when I got over 1 per hour I talked to the nurse just to advise they were rapidly increasing and she had me go in right away (next day) and see a pulmonologist / sleep tech kind of person to see what was up.

[JohnBFisher]

... Mary Z, rescan is recording the events as Central apneas rather than Clear airway. ...

Actually, we use the phrase "clear airway", since you can not really determine from the machine if the event is just due to a clear airway (while awake, during sleep transition, during movement, etc.) or due to a central sleep apnea. You need information from the EEG to determine if it is truly a central sleep apnea. No matter what the report says, the only thing you can know for certain is your airway was clear and it might be a central apnea.

However, if you continue to feel horrible - especially if you continue to have problems with elevated blood pressure (or other adverse symptoms) - you should discuss this with your doctor. But be certain you give the original titrated settings a go - with reporting - to show they do not meet your needs. For example, my neurologist has no problem if I tweak the settings if I can show that (a) it improved my situation and (b) I have data to back up my claims.

However, please be aware that you will have to have a higher number of central apneas before a doctor will feel it is necessary to intervene. Also remember that the number of centrals that ResScan (or any other software based on your machine's data) shows will probably be higher than what a PSG would show, since the sleep study software will throw out the centrals that do not fully meet the definition of a central sleep apnea.

Just some thoughts. But I definitely agree you are probably at the point where you should discuss this with your doctor.

[jedimark]

I get these same sort of clusters, at unexplainable times quite frequently.. Sometimes over an hour long sessions of periodic breathing.
I wake up with a dull crummy headache every morning.

I have recently switched to using an IntelliPAP Auto machine, so I can collect some data for finishing off SleepyHead's support for it. This machine does not have a pressure pulse algorithm like my PRS1 Auto does (or the ripple algorithm of an S9), and behaves quite differently during these clusters. It ramps the pressure up like a freight train. (I've got it the upper set to max at the moment, same settings as my PRS1 was last)

I haven't got all the numbers to report yet as I still working on SleepyHead's IntelliPAP support, and I still haven't installed the SmartLink software on the wife's Windows PC yet so I've got the reports to compare it with.

But I can report it's slightly 'brutish' behaviour has caused a minor, but noticeable reduction in severity of my headaches and fog..

I'm not advocating a change in machine or putting one machine over another here, simply giving my anecdotal comparison between the treatment methods for this kind of thing.. One is treating them like centrals (without proper evidence they are such in my case), and the other is treating them like apneas.. Not enough time has passed for me to make a better judgement on this, but I am feeling a slight improvement with the latter method.

The PRS1's 90% pressure is similar to the IntelliPAP's 90% pressure, but the PRS1's maximum is lots lower.. The PRS1 refuses to push much further the 90% figure. The IntelliPAP makes sure I know what the upper limits are all about.. especially on waking up.. I lie there awake and it keeps upping the pressure.. I'm probably waking from a high pressure during such cluster, and maintaining the whacked breathing pattern.

Only wish I could see the flow waveforms to compare it.. (DeVilbiss Marketing... Pretty Please, can we have the Flow Waveform saved on IntelliPAPs SD card??)

In my case, my weight probably has something to do with these clusters.. My BMI is currently sitting between 30-31, and dropping very slowly.
Not that I can remember feeling that much better back when I was lighter, but dropping the extra kg's isn't going to harm me (all that much. )

[summer]

Hi JohnBFisher,

Thanks for your reply, I did show a number of centrals during my sleep study, but my impression is that OSA can result in hyperventilation, which is what I get after such events this tends to then result in some CSA's, the hyperventilation sought of generates disruption like ripples in a pond effect. I agree that the machine cannot give a 100% confirmation of whether the central apnea are in fact central apnea!, but I would like some how to reduce them.

Hi Jedimark,

That's interesting that you have similar nights in the past, I take it that you just took those nights as blips and did not adjust anything?. By the way I think your GUI is much better than Resmeds!!

[DeVilbiss Marketing]

Only wish I could see the flow waveforms to compare it.. (DeVilbiss Marketing... Pretty Please, can we have the Flow Waveform saved on IntelliPAPs SD card??)

Point noted Jedimark