Resmed VPAP Adapt SV - for Central Sleep Apnea

[rested gal]

But this chart seems to show no blue step
http://www.internetage.com/cpapdata/menu_0826.html

ok, I'll continue to regard the blue line the way I did after James Ball's post. Blue line for hypopnea.

Either way, at least we all know that a blue line from start to finish in an hour doesn't automatically mean there was an hypopneic situation that lasted for an hour.

I'm sooooooo glad to have machines that use Encore Pro and Silverlining software instead of autoscan.

[dsm]

But this chart seems to show no blue step
http://www.internetage.com/cpapdata/menu_0826.html

ok, I'll continue to regard the blue line the way I did after James Ball's post. Blue line for hypopnea.

Either way, at least we all know that a blue line from start to finish in an hour doesn't automatically mean there was an hypopneic situation that lasted for an hour.

I'm sooooooo glad to have machines that use Encore Pro and Silverlining software instead of autoscan.

Yes I guess that even a Reslink module with all its data, doesn't make that hypopnea line any easier to understand.

Must confess that I always go by the AI & HI numbers in the summary chart & just look to the blue pyramids to get a sense of when & to what extent the hypops were occuring (except, the way the hypop average is kept by the hour, is without doubt not helpful).

DSM

[StillAnotherGuest]

The apnea-hypopnea summation is plotted as a blue line on the Apnea Events graph in the Night Profile (Figure 25).

If they're calling it "AHI", then one would think that the blue line should include apneas, otherwise the label would be HI.

If re: the maximum length of an event, it can't be more than a couple of minutes, that's the span of the floating window used to establish a baseline. If the whole baseline is one particular waveform, then that's now the baseline, otherwise how could it identify an event. There has to be an "exit threshold", a point where it just says "Forget it, this can't be an event." I don't know what is for ResMed, but for Respironics

In step 84, the algorithm determines whether the patient has been in the apnea/hypopnea condition for greater than 75 seconds based on the amount of time accumulated on the duration counter. It has been clinically determined that a human cannot remain in an apnea/hypopnea condition for more than 75 seconds. Therefore, the algorithm considers the A/H condition to have been erroneously entered if the duration counter exceeds 75 seconds and terminates the algorithm in step 86 and exits in step 88. At which time, the duration counter is reset and the process returns to step 52.

SAG

[frequenseeker]

DSM, those are interesting graphs. The difference in the nights with the different bipap settings is quite striking. The minute volume graphs are significant I believe, for the size and pattern of fluctuations. It would be interesting to see some comments and analysis on this, and the correlation with the oximetry.
Your MV on 1/11 had a volatile looking range of 5 - 20+. on 1/13 the range was more restrained 8-12 more generally. (Mine BTW is 2-4 on the onscreen stats, which is all I can get at the moment. ASV cable/autoscan wante the computer to have a serial port and XP. My XP machine has a USB and my serial port machine has Windows 98 )
Your tidal volume statistics also are worthy of note. You have a backup rate of 6 which you don't get very close to, it seems.

Regarding hypopnea bluelining on the graphs, I apologize if I forgot that I had asked about that a long time ago and had the answer back then. I have not had to think about that blueline for months not having had it on my graphs since the ASV doesn't provide AHI data currently. So I think I confused the question with what I actually had in mind in talking about longlasting hypopneas, which was respiratory rate (and volume?) depression.

_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): bipap, AHI, Hypopnea

[christinequilts]

I have essentially no choice about the mask. I tried the Vista on my face for several nights and was unable to get it to fit properly, not leak and not wake me up.

How much did you play around with the Vista mask? Its not as simple as their 'set it and forget' marketing makes it out to be, but it is an approved Adapt mask. What about the UltraMirage II or the Activa? Or even a non-ResMed mask that can pass the learning circuit on its own, without a pinch hitter? Why is it you're so attached to using a Swift mask? Try holding the Vista, minus the headgear up to your nose- can you get it to fit without leaking? Play around with were it sits on your nose and the angle its held at. Once you get a pretty good spot, then work with getting the headgear to hold where you need, deconstructing it if you need to. I ended up cutting the plastic stabilizing 'hooks' on the straps that go under my ears to make mine work better. Also, notice you can adjust the angle by pressing the tabs in on the plastic part of the headgear and by adjusting how close the top crossover buckle is to the front of your head.

Believe me, I've been tempted to throw my mask, and some nights even my Adapt, across the room because of mask issues, but I made a commitment to myself. I could have easily pulled out my Comfort Curve and hooked up to either my original tank-like BiPAP STD or my Synchrony BiPAP ST, but I knew the hassle of the mask wasn't worth giving up my Adapt. I am having an awful time right now with my dermatographism causing welts that open if I'm not very careful to rotate masks, sometimes part way through the night. If I can make it work, anyone can.


Also, back from your post last fall about your results going up as you increase your base pressure:

It has seemed to work fine for my early night type of CSDB from the beginning, but using it all night and feeling better were challenges until I raised the pressure from 6 to 7, then 7 to 8, then 8 to 9.
At 9 I had a dramatic change. I feel much better and I can sleep all the way through.
Interestingly, at each increase, my results increased by 1.2 to 1.4 points. Exactly, each level up. Odd. Dr Gilmartin and I have been discussing it but no clues. I even went back to 8.4 and got the corresponding result of 9.8!

I assume you have to mean your average pressure went up? All The Adapt reports in the patient menu is the mask fit, average pressure, hours used and in the clinical menu, it reports leak, average pressure, tidal volume, respiratory rate, and minute ventilation. You do realize the average pressure is going to increase if the EEP/base pressure increases? If you're getting an average of 9.8 with a EEP of 8.4, then it looks like you are spending most of the night at 8.4/11.4 (assuming minimum pressure support of 3/max 10). In comparison, my EEP is set at 9, minimum PS/max 10, and my average pressure is 10.8-11.2, depending on the night.

[dsm]

[quote="frequenseeker"]DSM, those are interesting graphs. The difference in the nights with the different bipap settings is quite striking. The minute volume graphs are significant I believe, for the size and pattern of fluctuations. It would be interesting to see some comments and analysis on this, and the correlation with the oximetry.
Your MV on 1/11 had a volatile looking range of 5 - 20+. on 1/13 the range was more restrained 8-12 more generally. (Mine BTW is 2-4 on the onscreen stats, which is all I can get at the moment. ASV cable/autoscan wante the computer to have a serial port and XP. My XP machine has a USB and my serial port machine has Windows 98 )
Your tidal volume statistics also are worthy of note. You have a backup rate of 6 which you don't get very close to, it seems.

Regarding hypopnea bluelining on the graphs, I apologize if I forgot that I had asked about that a long time ago and had the answer back then. I have not had to think about that blueline for months not having had it on my graphs since the ASV doesn't provide AHI data currently. So I think I confused the question with what I actually had in mind in talking about longlasting hypopneas, which was respiratory rate (and volume?) depression.

[rested gal]

The apnea-hypopnea summation is plotted as a blue line on the Apnea Events graph in the Night Profile (Figure 25).

If they're calling it "AHI", then one would think that the blue line should include apneas, otherwise the label would be HI.

LOL!!! Please scoot over a little, JimW. I'm jumping back over to your side of the blue line.

Geeze, what a graph.

[Snoredog]

The apnea-hypopnea summation is plotted as a blue line on the Apnea Events graph in the Night Profile (Figure 25).

If they're calling it "AHI", then one would think that the blue line should include apneas, otherwise the label would be HI.

LOL!!! Please scoot over a little, JimW. I'm jumping back over to your side of the blue line.

Geeze, what a graph.

Geeze WARN me next time will ya!!

that one just sprayed the ice tea I was drinking out my nose all over my laptop. The dogs tttttttttttlmmmmmmppp ppp aeeeee are now licking
it off the keyboard
ssssed



God I hope that tea doesn't keep them up tonight.

hehehe I told you guys those reports were poo poo

[StillAnotherGuest]

My PB330 does not give resp rates anywhere near what I seem to be able to drum up from the Vpap III S & S/T ...

My regular machine is always the BP330 - as I often say, it is the best I have ever come across except it doesn't record nightly data -

Well, my first question would be, how do we really know what the PB330 is doing without at least some kind of objective data. But even with that, if the question is can one make definitive conclusions about SDB using a one-channel monitor (minute ventilation) like being able to differentiate normal, or controlled state



from "neat" CSDB



from "messy" CSDB



from CSR



the answer is you can't, because you can also generate at least a "messy" CSDB-looking Minute Ventilation waveform by Wake, by washing down an Effexor with a can of Mountain Dew at bedtime, and by a myriad of other things. However, if you can consistently generate stable waveforms on CPAP, and major disruption on aggressive BiPAP, then you gotta think that the latter is generating airway instability. Does this equate to CSDB? If everything's peachy on CPAP, then crazy on aggressive BiPAP, that's more of the "iatrogenic" SDB (you're making it happen). Refer back to the "How To Mess Things Up With BiPAP" articles or the concept of jacking up the controller gain part of the "loop":



At a given chemical response (PcrCO2), adding in pressure support (in this case Proportional Assist Ventilation) will increase the resultant minute ventilation (VE), and the wagon starts merrily careening down the hill (oh no, not THAT thing again!)

In striving for the definition of CompSAS (right, there isn't even any agreement on what to call CSDB) the Morgenthaler et al group at Mayo have a great concept where

Patients were considered to have the CompSAS if CPAP titration eliminated events defining OSAHS, but the residual central apnea index was 5 or more per hour or Cheyne-Stokes respiratory pattern became prominent and disruptive.

In other words, no central apnea, or more importantly, no residual central apnea after optimal therapy, then no CompSAS, CSDB or whatever you want to call it.
SAG

[dsm]

SAG,

You make your point well - those samples of breathing are quite something. Were they simulated or are they real people's breathing patterns (they look real but the bottom one is scary - is it CSB ?).

With the diff between the PB330 & VPAP III - what I notice is that on average, I feel I sleep a lot less (lighter) when using a VPAP III configured the same as the PB330 but I have recently noticed that the pressure readings at the face mask compared to at the machine, vary by about 1 cms with the VPAP III compared to the PB330 which shows the same pressure readings at either end of the tube. The PB330 of course has an internal air pressure sensing line. I am still doing more testing on this to make sure I am getting the data right.

Also with the VPAP III, I always feel like I have been 'supercharged' the next day. Even if I may feel I slept less, I get this feeling that at best I can equate to what happens to a cat when you rub its fur (eyes go wide, kitty's fur starts to build up static, kitty becomes supercharged). The other thing I notice, as previously mentioned, is when I do wake in the early hours (tend to do so regularly at 2am-2:30am) with the VPAP III, I will be breathing faster than I am aware of doing with the PB330.

One reality is that I have never used a VPAP III for moe than approx 1 week at a go (noise issue for wife). But have been using the PB330 regularly for about 1 year. That could have some bearing on the short term impression I get.

It is a pity the PB330 doesn't record data as the info would be so useful to compare against what I can get from Autoscan for the VPAP III.

DSM

[Lubman]

Freqen --

The FDA has not cleared the ASV yet for including AHI info in its data.. So I believe it is the tidal volume that is analyzed to see if cyclic breathing is occurring.

What do you mean? The FDA doesn't usually approve something part way --- what is your source for saying the ASV isn't "cleared" for including AHI in the data. What do they get another round at having the machine compute and report ratios?

Does the machine have to derive indices differently than other BiLevel or XPap machines?

Can SAG, DSM or RG shed some further light on this statement, as I don't quite follow the statement as worded.

Lubman

[dsm]

Freqen --

The FDA has not cleared the ASV yet for including AHI info in its data.. So I believe it is the tidal volume that is analyzed to see if cyclic breathing is occurring.

What do you mean? The FDA doesn't usually approve something part way --- what is your source for saying the ASV isn't "cleared" for including AHI in the data. What do they get another round at having the machine compute and report ratios?

Does the machine have to derive indices differently than other BiLevel or XPap machines?

Can SAG, DSM or RG shed some further light on this statement, as I don't quite follow the statement as worded.

Lubman

[StillAnotherGuest]

It'll be interesting to see that algorithm. I would offer that you might not be able to report out AHI (AI, anyway) because central apneas may not be accurately assessed using ASV. Let's say ResMed uses a 75% reduction in flow to define an apnea. As soon as AdaptSV sees an impending apnea, it rapidly increases pressure to achieve 90% of Target Ventilation relative to recent baseline. So if it works even close to the way it's supposed to and it's set up correctly, you shouldn't really see too many apneas. This does not automatically infer that the CSR or CSDB cycle has been broken, which is what you really want to know, but this can be inferred from other parameters, like Minute Ventilation (which might even be a little more sensitive in tracking cyclical phenomena).

Or maybe it's a marketing thing. If you do have apneas, then maybe "It's not all that amazing."

Or maybe they're gonna use SAG's idea of Incomplete Event Attack (IEA).

Speaking of which, those AdaptSV Minute Ventilation waveforms are real examples of the stated phenomena.
SAG

[StillAnotherGuest]

Oooh, better idea. Berthon-Jones had been working on patents for methodology to identify open airway apneas (centrals) a long time ago. Since this is really a central-based machine, then wouldn't it be absolutely essential to differentiate central from obstructive? If they were obstructive, then you would increase the EEP. If they were central, you would work on the PS.
SAG

[frequenseeker]

Yes, the ResMed rep said that the ASV had been approved by the FDA except for the inclusion of AHI information and rather than hold up release of the machine, ResMed put it on the market as is. He said it was expected to be at least another 6 months of testing and proving, before the approval would come through to allow those measurements to be provided by the machine.
I don't know anything more detailed. Naturally we wonder if it will just be another version of the software or if some sort of upgrade for the machine itself will be involved.

Christinequilts:

How much did you play around with the Vista mask?

I believe I tried it well enough. I had quite a few nasal masks in the pre swift days and got a good orientation. I appreciate the helpful tips, and maybe if I got my DME involved we could try it again. In the past it was only the F&P Acclaim that had any (intermittent) success. I had terrible marks on my face, and alot of interrupted sleep, though.

Why is it you're so attached to using a Swift mask?

Because it attaches so well to me I can really rest with it on, very simple. Also the direct delivery into the nostrils seems to work well for me, I am not sure I can describe it more than that. Perhaps due to my asthma I like the way the swift delivers the humdified, pressurized air directly into the airway.
Dr. Gilmartin just wrote me that they tested the Swift in their lab to make sure it worked with the ASV and they found it had "excellent performance."

He also answered my question about why it is uncomfortable during the Learn Patient phase. It is designed to deliberately push over and under the ventilation baseline to determine the algorithm, because it cannot otherwise passively learn the patient's ventilation. After this short phase it should be comfortable and effective, so it is just something to be endured.

_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): resmed, swift, DME, AHI