Am I on the right track? Not feeling it yet.

[Sleeprider]

No changes for now. We need to give this one more time. My concern is that the machine is not behaving as expected.

[benseidler]

ok... I will give it a couple of days and report back... If we see the same thing, I can send this over to my sleep doc and ask him what the deal is... I am still in my 30 day trial period, so I can ask about switching machines also...

Thank you very much for all of the help.

[Sleeprider]

In my previous post I posted an example of the response of a S9 VPAP adapt machine. Here is an example of your SV Advanced. Note how the pressure changes work to mitigate events, not perfectly in this case, but with much more pressure support than your machine is delivering ever.

[vsheline]

.... My concern is that the machine is not behaving as expected.

The pressure appears to be adjusting automatically all right, but in SleepyHead (SH) it is the "Mask Pressure" plot (instead of the "Pressure" plot) which shows the high rate pressure waveform, showing how the pressure varies in real time. There will be some way in SH to enable display of the Mask Pressure plot.

Hi benseidler,

May be best to leave the new settings as is for a while.

I think the hypopneas are mixed, both central and slightly obstructive. The Flow waveform looks like you are having trouble getting enough air, so occasionally you quickly (but still smoothly) increase breathing effort for just a few breaths, after which you tend to pause or breathe too shallowly for a short time. It could be that more Min EPAP is needed and/or more Min PS.

I think this unstable breathing may be helped by increasing the Min PS. But if you can, I suggest leaving things at their present settings for preferably a week, to let you get weekly statistics at your present settings. After that I suggest increasing Min PS by 1 (to 3) for one night to get used to increased Min PS, and then increasing the Min PS to 4 for a full week, to get new weekly average statistics with Min PS of 4.

Unless one has an ASV machine (like you do) I wouldn't suggest increasing Min PS when the breathing is occasionally unstable (like yours is) because increased Min PS could increase central events, but your ASV machine will handle/treat central events just fine, so more Min PS should be okay. And the benefit of higher Min PS would be twofold.
(1) it will be easier to breathe because the machine will be doing for you more of the work of breathing, so you'll be getting more air with less effort.
(2) this increases your average Tidal Volume (TV) and average SpO2, which I think likely would make your breathing more stable. (TV is the Volume of air breathed in one breath.)

After that, if the hypopneas are still occurring too frequently then I would suggest raising Min EPAP a little more.

[benseidler]

I have let this play out for a few weeks, played with some pressure settings, and things just seem to be getting worse.

I can't make heads or tails out of what is going here, and why this machine is not stopping the central apnea events from happening.

Does this look crazy to you guys?  My AHI has been bouncing between 15-30 for the last few weeks.

Screen shot below

[attachment=3119]

[Sleeprider]

Ben, go into your settings and make your PSmin 2.0. You may even want to make it zero. You may be causing centrals through your base pressure support of 4.5. For some reason, the machine is not increasing PS upon sensing a CA or H event. I'm pretty sure you can reduce the number of events by limiting PS min, but I would expect to see the machine increasing pressure to cause a breath during CA, or increase respiration in a hypopnea. The largest pressure increase you are getting is only 1-cm according to the data.

This latest data confirms my earlier suspicion, that something is wrong with this machine. It is not providing pressure support as needed on a breath by breath basis. If it is under warranty, return it.

[benseidler]

Ben, go into your settings and make your PSmin 2.0.  You may even want to make it zero.  You may be causing centrals through your base pressure support of 4.5.  For some reason, the machine is not increasing PS upon sensing a CA or H event.  I'm pretty sure you can reduce the number of events by limiting PS min, but I would expect to see the machine increasing pressure to cause a breath during CA, or increase respiration in a hypopnea.  The largest pressure increase you are getting is only 1-cm according to the data.

This latest data confirms my earlier suspicion, that something is wrong with this machine.  It is not providing pressure support as needed on a breath by breath basis.  If it is under warranty, return it.

Thanks Sleeprider... I will try that in parallel with trying to return it.

How do you recommend that I go about getting my DME onboard that the machine has an issue? Do you think showing the sleepyhead data will be enough to get them to agree? I have had it less than 2 months, so it is definitely still under warranty.

[benseidler]

one other thing... i think the respironics shows the pressure in the mask pressure, and not necessarily the pressure grid... If you are looking at the mask pressure instead, does that change your thoughts any?

[Sleeprider]

The mask pressure shows me exactly what I need to know, but similar data is available on the pressure chart. What we see is that mask pressure increases on a breath by breath basis at the minimum pressure support setting, and it does that even when it should be increasing pressure to help increase inspiratory volume during hypopnea and CA events. The machine should be using up to your maximum PS to treat inadequate or non-respiration. It never gets above 14 cm, even during a central event. That is a malfunction.

Try to get a Resmed Aircurve 10 ASV...Much better machine for what you need.

[gman5200]

The mask pressure shows me exactly what I need to know, but similar data is available on the pressure chart.  What we see is that mask pressure increases on a breath by breath basis at the minimum pressure support setting, and it does that even when it should be increasing pressure to help increase inspiratory volume during hypopnea and CA events.   The machine should be using up to your maximum PS to treat inadequate or non-respiration.  It never gets above 14 cm, even during a central event.  That is a malfunction.

Try to get a Resmed Aircurve 10 ASV...Much better machine for what you need.

 If you have clinician's manual check the modes section. It looks like DME has it set to a variable Epap only. Should be autosv or something like that.
Could be wrong and if so I agree it is broken.