Resmed VPAP Adapt SV - for Central Sleep Apnea

[dsm]

Did the DME you obtained your Synchrony from also carry ResMed machines? Maybe you can call them and ask if either the VPAP Adapt SV (US name) or the AutoSet CS2 (name used in some countries) is available. If it is, start bugging your sleep doc. Let us know what you find out.

Bella, if you can't get the resmed machine (by either its US or Australian names) the Respironics ASV machine Christine mentioned is available here:

https://www.cpap.com/productpage-advanced.php?PNum=2471

Reading this link & esp this part
"On a breath-by- breath basis, the revolutionary algorithm uses Digital Auto-trak Sensitivity to change pressure support, when necessary, to maintain a stable breathing pattern.

In addition to this breath-by-breath adjustment of pressure support, the Bipap Auto SV algorithm also calculates the patient's spontaneous breathing rate and will automatically trigger a breath should the patient have an apneic event. This algorithm rapidly helps normalize respiration and turn the pressure to the minimum required therapy pressure once ventilation has been normalized.

In addition to the revolutionary algorithm, the Bipap Auto SV sleep therapy system also offers other Respironics technologies such as optional integrated heated humidification and built in digital data storage using Respironics Encore Smartcard and Encore Pro Data Management software.
"

Plus looking at the images ...

Leads me to believe that the 'Bipap Auto SV' is most likely the current Bipap S/T machine with added algorithms perfected in the Bipap Auto and extended to work in the Bipap S/T body & electronics (which technically is quite a bit more complex than the Bipap Auto machine). It looks like it uses the same fixed speed blower combined with an 'air valve' to control the air flow & pressure. The existing Bipap blower/air valve design is old but very reliable and very effective, its only real issue is the cost of manufacture & that is on the high side.

I note that in the above excerpt they do talk of it being "revolutionary algorithm" so that looks like it means that the machine is a software advance rather than a technological (electronics & hardware) advance.
Further confirmation of this for me is that they don't (can't?) work off minute ventilation but go on 'peak flow' which allows a broader interpretation of what is going on between machine & mask. The bipap relies on Auto-Trak to guess what is leaking & what isn't & that has always been a challenge for them. I see Auto-Trak is mentioned as providing the PS support.

The machine looks like a software response to the Resmed AutosetCS2 (Vpap AdaptCS).

#2 One thing I would like to explore is how the BipapASV achieve's this ...
"will automatically trigger a breath should the patient have an apneic event"

The dynamics of how the the machine 'automatically triggers' a breath would be interesting to explore - how do we trigger a breath when an apneic event occurs ?. Any thoughts SWS? SAG? RG?

DSM

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[frequenseeker]

Christinequilts,

I'm impressed with your review of my posting history. Some of the details to which you refer certainly are useful to have so well compiled.
I think I will just list a few responses here to continue to work the process with you.

We see that I did have multiple hypopneas in the early data.
I will ask about the CO2 levels specifiying the values as SAG noted.
I did not ask for the EERS, it was given to me during the initial study and the effects were monitored. In the original study report, this what I was referring to when I said "cyclic":

She has periodic breathing during unable NREM on CPAP.

During the recent study, at the end of the wake period the length was increased and shortly afterwards I went back to sleep. I have not had that increased length to use yet at home as the supply company has been slow in sending it.

I do not have GI function problems in general (yes there are foods that don't work well for me; they are avoided) . The reactions I had in the study are familiar to me clearly as autonomic stress reactions that I have felt when waking up with gasping apnea or in emotionally stressful situations. These are also the vasospasms in the early morning that lock up my back that correlate with having had vivid dreams and apnea. I know that the system can work back the other way, GI problems could bring on the ANS reactions etc. and I have considered what has been suggested about that here, but I believe this is not the way it is for me.

When I awoke in the study with the too rapid breathing rate and chills etc, I tried to work through it and get back to sleep. It was impossible (as the graph shows). The stomach motility stopped soon after for the rest of the night but the chills and wakefulness continued, until the last adjustment when I suddenly got nice and warm and went to sleep.

About my respiratory issues having cleared up. It is true I had good PFTs then. Thought the bipap was responsible. Might have just as well been because I had moved and no longer was using an indoor hottub, as that might have been the source for lung infection... Just throwing that in..it is so hard to pin these things down.. I have been having more trouble in the past few months, and had a basic PFT done that showed asthma type results again. Exercise as in walking or jogging was uncomfortable, with alot of pain (like starving for oxygen) in my back and arms if I tried to exert (this was in the winter with colder air to breathe too).

I had the swollen neck glands and did antifungal, and antibiotics when I got a sinus infection, still have some problem with those glands and sinuses.
In the past couple of weeks feeling better, I also can exert more without painful reaction and my lungs seem better. Is it the reduction of infection, or the onset of spring with warmer air to breathe, or the end of using the ASV?? Don't know if there is any way to tell.
I am getting a full PFT eval in the near future at BI.

I used auto CPAP for a while, the graphs looked not good, and I felt very bad. This was before I went to BI.
I've had cpap with EPR, don't remember any negative on it in general.
I've had RR of 10-12 with a number of machines. I have been using the VPAP III on cpap mode for the past several weeks and my RR is 10-12 with that. So it isn't a result of the IPAP/EPAP settings on the bipap VPAP..

You suggest that I may not have given the "permissive flow limitation" a chance, through increasing my pressure level once I got home with the ASV, or cpap for that matter. I can only report that I was waking with gasping and internal spasm and obvious apnea on the setting originally recommended. I am guessing that in the study I may not have gotten into as deep sleep for as long or as many times as I did when I was home, so the basis for the recommendations might not have been representative.
BTW when I tried a full face mask in the past, I had the same situation. It solved the arousing mouthleaks I had not yet solved in other ways, and when I got that deep for that long...well, that is how it seemed to me..

My current cpap pressure is 11.4, there are no "unorthodox settings" in use. I don't see how the mouthguard would play any negative role. I have tried without it and mouthleaks are the clear result.
I still am taking off the mask in the early morning and going back to sleep and getting the dreams and apnea then. My remaining congestion from the sinus infection appears to be an influence at the moment. The pattern historically is that I wake supine with discomfort in the back, need to turn on my side to get back to sleep and can't with the pap on as I get aerophagia in any other position. I theorize that the back discomfort (internal spasm) is related to the pap not obliterating or preventing the REM apneas prior to my waking.

I do appreciate everyone's input here and will incorporate it into my efforts to bring both my personal situation and the questions of principles into resolution.

frequenseeker

[frequenseeker]

Oh, and once I am more well (from the cold and feeling like I have more reserve) I can see about doing some trials with the Vista to further explore some of our questions. Seems like the last thing I could explore at home.

FQ

[Lubman]

Leads me to believe that the 'Bipap Auto SV' is most likely the current Bipap S/T machine with added algorithms perfected in the Bipap Auto and extended to work in the Bipap S/T body & electronics (which technically is quite a bit more complex than the Bipap Auto machine). It looks like it uses the same fixed speed blower combined with an 'air valve' to control the air flow & pressure. The existing Bipap blower/air valve design is old but very reliable and very effective, its only real issue is the cost of manufacture & that is on the high side.

So, DSM, you are saying that in your opinion the Respironics solution is a software enhancement of existing hardware, whereas, the ResMed ASV is a dual blower hardware design with its own different and unique algorithm.

ResMed is able to determine minute vent. whereas Respironics utilizes peak flow. Why don't you offer some additional opinions on the differences of using MV versus Peak Flow?

Also, CQ - I am also impressed by your summary of FQ's posts, over the past few years. You have a very good, logical way to describe such things.

Lubman

[christinequilts]

There is a relatively new medical research field called neurogastroenterology. I would love to see you and Gilmartin team up with some of those researchers. My "gut" instinct is that medical research from these two fields needs to merge, for some unknown epidemiological percentage of patients.

I finally remembered to go back to read the article you had linked and it is an interesting area of medicine. I don't know if I would call it a new field, but a specialization of research oriented motility GI docs. My former GI doc was on the steering committee for International Group for the Study of Neurogastroenterology and Motility, which started back in 1991, so the construct has been around for awhile.

I've seen a few neurogastroenteroloist over the years for my gastroparesis...if you guys think being wired up for a sleep study is weird, imagine being wired up for an EGG (electrogastrogram) on your stomach. It had to be done in a special room that eliminated any outside electrical interference in order to 'hear' what the stomach nerves were saying. Considering my former GI doc is suppose to be one of the top neurogastroenterologist, head of the GI dept at a major university hospital and is highly involved professional societies related to neurogastroenterologist (including as past president of AMS), I was never too impressed with his knowledge of sleep issues or much else outside of GI itself. Might be because I reported I did better at night staying asleep & had less waking with nausea when I took Ambien (pre-CSA Dx), so he prescribed Ambien to be taken during the day time too. I questioned him about, asking if he realized it would do (ie- staying awake during the day, reducing its effective at night as a sleep med, etc) and he was adamant it wouldn't be a problem Needless to say, I didn't take Ambien during the day and pretty much lost all trust in him at that point, finally deciding to have my local GI doctor take back over all my care when he went down to seeing patients 1-2 days per month.

On the other hand, my sleep doctor, who is not a researcher, just a practicing sleep physician, has always felt there was some sort of connection between neuropathy that resulted in my severe gastroparesis and my CSA. And he's helped me better understand how my GI issues can affect not just my sleep, but all my medical issues more so then any of the numerous GI doctors I've seen. If we could get him in contact with a neurogastroenterologist who doesn't have the problem Snoredog suggested with the picture he posted, I think they might just get somewhere.

[dsm]

Leads me to believe that the 'Bipap Auto SV' is most likely the current Bipap S/T machine with added algorithms perfected in the Bipap Auto and extended to work in the Bipap S/T body & electronics (which technically is quite a bit more complex than the Bipap Auto machine). It looks like it uses the same fixed speed blower combined with an 'air valve' to control the air flow & pressure. The existing Bipap blower/air valve design is old but very reliable and very effective, its only real issue is the cost of manufacture & that is on the high side.

So, DSM, you are saying that in your opinion the Respironics solution is a software enhancement of existing hardware, whereas, the ResMed ASV is a dual blower hardware design with its own different and unique algorithm.

ResMed is able to determine minute vent. whereas Respironics utilizes peak flow. Why don't you offer some additional opinions on the differences of using MV versus Peak Flow?

Also, CQ - I am also impressed by your summary of FQ's posts, over the past few years. You have a very good, logical way to describe such things.

Lubman

[christinequilts]

CQ - I am also impressed by your summary of FQ's posts, over the past few years. You have a very good, logical way to describe such things.

That use to be a big part of my job, conducting file reviews and making sure everything matched up. Workers' Comp doesn't like paying for things not related to original injury and sometimes you would come across someone who was so sure every symptom they had just had to be a result of their WC injury, so you'd have to lay everything out on the table and connect the dots. Other times I picked up on something that slipped through the cracks- the docs trusted me since I was the first to go to bat for a patient when needed, so they had no problem if brought up something they may have missed. We had one lady who was so focused her side & back pain was a result of a minor strain at work, but it didn't get any better after months of treatment. Going through her records, I noticed her GP has question if she gall bladder disease just prior to her injury date...sure enough, that's what was causing her pain.

ResMed is able to determine minute vent. whereas Respironics utilizes peak flow. Why don't you offer some additional opinions on the differences of using MV versus Peak Flow?

We have to remember Respironics has been able to determine MV for some time- it is clearly reported on Synchrony Encore Pro data- remember MV = tidal volume per breath x RR (or BPM). It looks like they are choosing a different measure to target additional PS. That makes me wonder if since ResMed got to the gate first using MV in xPAPs, if Resp didn't have to go with Peak Flow because of patent issues or something.

The other thing that's weird, is everything I've ever come across on ASV in clinical ventilation, always refers to MV as being the value to track/target, but I don't ever remember seeing Peak Flow used.

Description 2: Adaptive Support Ventilation (in reference to ventilators)
ASV was introduced in 1994 by Laubscher and coworkers.References 3 & 4 ASV may be thought of as an "electronic ventilator protocol" that incorporates the most recent and sophisticated measurement tools and algorithms in an attempt to make ventilation safer, easier, and more consistent. This mode is designed to accommodate not only ventilated patients who are passive, but also those who are actively breathing. ASV recognizes spontaneous respiratory activity and automatically switches the patient between mandatory pressure-controlled breaths and spontaneous pressure-supported breaths.

With ASV, the clinician determines the desired minute ventilation, and the algorithm determines the optimal respiratory-rate/tidal-volume combination according to the patient's respiratory mechanics. Any change in respiratory mechanics or patient effort results in an updated optimal breathing pattern (respiratory-rate/tidal-volume combination), and ASV continuously and gently moves the patient to the new, updated, target. Intelligent breath-to-breath safety rules maintain ventilation parameters within safety ranges, and if for any reason the patient fails to breathe actively, ASV automatically increases the number of mandatory pressure-controlled breaths needed to maintain the minute volume target. ...

The intrinsic requirement for determination of the optimal breathing pattern is the breath-to-breath measurement of respiratory mechanics, including the expiratory time constant, based on the volume-flow loop method.Reference 5

Figure 1 shows a part of the ASV screen as implemented on GALILEO, with the selected minute ventilation target (green curve), respiratory-rate/tidalvolume target (target circle), the patient's current status (yellow cross), and the safety frame (large red rectangle).


Figure 1: Highlight from the ASV screen implemented on GALILEO.

New Modes of Ventilation: Proportional Assist Ventilation; Adaptive Support Ventilation; SmartCare

Even SAG's description of how ASV works doesn't mention peak flow:

OLT, the concept of ASV has similarly been around a while, under a variety of names. It might be a good idea to start out with the basic concepts of ASV, and then we can apply this to what these "servo" machines pick and choose:

Adaptive Support Ventilation
• If no spontaneous effort to breathe, machine delivers required minute ventilation (VE) as pressure control, comprised of pressure support (PS) and rate (f).
• If patient starts to breathe spontaneously, machine reduces f and lowers PS to keep VE above set minimum.
• If spontaneous tidal volume (VT) is > target and f <target, PS is reduced and f is increased.
• If VT > target and f > target, PS is lowered and f is reduced.
• If VT < target and f > target, PS is increased and f is lowered.
• If both VT and f are < target, machine increases f and PS.

So that raises the question, is the Resp ASV really ASV [/url]

[dsm]

CQ,

Very impressive

You may have been in the wrong profession - I can see a technical researchers mind well at work here.

Good reading & well put.

DSM

[rested gal]

CQ - I am also impressed by your summary of FQ's posts, over the past few years. You have a very good, logical way to describe such things.

Lubman

CQ,

Very impressive

You may have been in the wrong profession - I can see a technical researchers mind well at work here.

I agree with you both. I've always been impressed with christinequilts' logical mind and attention to details as well as ability to look at the big picture.

Frequen, you'll do what you want; but, if it were me, I'd strongly consider Christine's suggestion that she put in bold, several posts up:

Start over with non-treatment PSG to see what you are treating

[christinequilts]

You may have been in the wrong profession - I can see a technical researchers mind well at work here.

I was working on my PhD until I became to ill a few years ago...hopefully I'll be able to go back at some point and finish it. I loved teaching in particular, which surprised both my mentor & me. Especially when after my first lecture when he told me the things he wanted me to work on were normally things he wouldn't worry about until the end of the first year. I knew I was doing something right when he left classroom- which he rarely did when he had a junior co-instructor.

[dsm]

Christine,
PhD, nuf said

Re a comment you passed in an earlier post about wondering if patent issues were possibly why each company is going about MV monitoring & PS support differently, the latest Resmed Malibu release seems to me to support that thought - I guess we won't know for sure unless someone from either company says so & I doubt their job would be worth speaking out on this particular point.

I had begun to wonder about patent issues when looking at how Auto-Trac worked.

DSM

[christinequilts]

the latest Resmed Malibu release seems to me to support that thought -

I still have to laugh at the Malibu name, considering I called the S8 a Barbie Doll Suitcase...now they made a Malibu Barbie machine too
Now when will they add a Ken doll?

[dsm]

the latest Resmed Malibu release seems to me to support that thought -

I still have to laugh at the Malibu name, considering I called the S8 a Barbie Doll Suitcase...now they made a Malibu Barbie machine too
Now when will they add a Ken doll?

[-SWS]

The other thing that's weird, is everything I've ever come across on ASV in clinical ventilation, always refers to MV as being the value to track/target, but I don't ever remember seeing Peak Flow used.

<snip>

OLT, the concept of ASV has similarly been around a while, under a variety of names. It might be a good idea to start out with the basic concepts of ASV, and then we can apply this to what these "servo" machines pick and choose:

Adaptive Support Ventilation
• If no spontaneous effort to breathe, machine delivers required minute ventilation (VE) as pressure control, comprised of pressure support (PS) and rate (f).
• If patient starts to breathe spontaneously, machine reduces f and lowers PS to keep VE above set minimum.
• If spontaneous tidal volume (VT) is > target and f <target, PS is reduced and f is increased.
• If VT > target and f > target, PS is lowered and f is reduced.
• If VT < target and f > target, PS is increased and f is lowered.
• If both VT and f are < target, machine increases f and PS.

Boy have I missed a lot. You guys continue to make fantastic strides sorting out the differences between these two Adaptive/Auto SV models.

Resmed at least attempts to sample, calculate, and deliver/control more instantaneous data points on the flow curve: hence "minute volume". By contrast Respironics samples, calculates, and targets just the top-most instantaneous data point on the same flow curve: hence "peak flow". SAG had mentioned this earlier, and I agree. If you sample and deliver one "peak flow" data point per inspiratory cycle, then that same patient flow-curve slope and thus "minute volume" (area under the curve) pretty much fall in line. From my perspective these two flow-curve data-point targeting methods can accomplish the same thing regarding how much ventilation occurs on each breath.

But another difference between these two machines is that the Respironics Auto SV employs a more traditional time-based back-up implementation rather than attempting to directly increase or decrease respiration rate (that variable "F" which Resmed's ASV algorithm manipulates). So, I agree that the Respironics machine does not purely meet that Adaptive Support definition above. Working with peak flow versus minute volume, in and of itself, probably results in no discernable functional difference regarding resultant ventilation. However, Resmed actively attempting to manipulate respiration rate (variable F) while Respironics makes no attempt to directly manipulate respiration rate truly accounts for one huge fundamental difference between these two Adapt/Auto SV design approaches.

Both machines still each attempt to monitor each breath, calculate the PS for each breath, then deliver that breath-specific PS during each respiratory cycle. But Respironics makes absolutely no attempt to increase or decrease F. You can absolutely guarantee different patient efficacy patterns on that algorithmic functional difference alone.

[dsm]

SWS,

Yup - absolutely - gives us choices plus great topics for endless debate

I think Respironics have been very clever in how they have coped with Resmed's manouvring.

I posted a link to their's & Resmed's shares today & they are tracking each other remarkably well. Here it is again

http://finance.yahoo.com/q/bc?t=1y&s=RM ... q=l&c=resp

The share market is where the analysts & observers vote

DSM

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