Resmed VPAP Adapt SV - for Central Sleep Apnea

[jammin]

The links rested gal provided were very helpful, and thanks for your reply. I got the Adapt SV on Wednesday. The machine works well, and my wife and I both appreciate how much quieter it is than the last setup I tried. I'm going through the predictable trouble adjusting to the mask, an Ultra Mirage Full Face, trying to get a decent fit without leaks and tolerate having it on my face for a whole night. I gather this is normal, and I'm trying to wear it a bit longer each night. Last time I tried a straight cpap, it was with a nasal mask and I had problems with mouth leak, which is why I'm trying a full face version this time. Not sure it's the best choice but it seemed a good place to start.

Something does feel different using the adapt. I'm a shallow breather even when awake, and when I go to sleep the centrals start. Getting more air seems to result in a somewhat tingley feeling that's different to me. That's not very well said but you get the idea. The asv does seem to do a great job of working with you and not forcing you into a rigid, mechanical breathing pattern.

The mask seems fine when I start the night but when I get close to falling asleep my jaw drops and it starts leaking - sometimes in a noisy way - and wakes me back up. I've spent a lot of time reading this thread on the asv. Guess it's time to read some of the threads on mask issues.

Anyway, thanks for the help. I'll be back soon.

[Lubman]

Jammin

Ultra Mirage Full Face, trying to get a decent fit without leaks and tolerate having it on my face for a whole night. I gather this is normal, and I'm trying to wear it a bit longer each night.

There are two keys to getting used to the UM FFM, I have used it for over a year.
a) It must be properly fitted and sized. The mask comes with a CD and the DME has a sizing tool to check you nose size. If they don't do that, you may not get the right mask size. I have a large shallow, and to just look at me that is not what someone would probably recommend.

b) It is important to have the mask snug but not really clamped down hard on your head. The mask is designed to seal when it is not so tight. The tradeoff is that if it is too loose it leaks, which with the ASV is not good.

The ASV is the first ResMed machine I have used. With Auto on, it rather
attaches and seals, much like when you turn on a vacuum cleaner and place it against a solid surface. It feels like it is "vacuum sealed" not quite a good analogy - to your face.

c) I also note the ASV is working with your breathing pattern. It doesn't simply hit you over the head with a large pressure to "fix" the problem.
It takes several minutes for the ASV to catch on to your breathing rate
at startup. But I know what you are talking about.

Lubman
Once you get used to the FFM, I find I like this particular mask.

[Lubman]

Let's focus a bit closer on the fundamental issues of complex sleep disordered breathing. After all, many of us who need one of these machines, simply don't fit the standard patterns which seem to have been used for a long time - either you have obstructive or centrals; or the research that was done because of heart failure that follows issues that have been studied in recent years; or the causes are unknown for your problem.

I'm going to assume one of the classic papers is "Recognition & Management of Complex Sleep-Disordered Breathing" Curr Opin Pulm Med 2005:11(60 485-493. It identifies a methodology to classify CSDB rather than loosely group it with OSA, CSA or "mixed" apneas.

The respiratory system is a control system, not unlike some of the electronic control systems that DSM and other engineers would understand, in my opinion.

Each person has different factors that impact just where the threshold is to stop breathing (e.g. apneas) or reduce but not stop the breathing (e.g. hypopneas). Each "control system" reacts a bit differently -- depending on where the threshold is that would trigger an apnea or hypopnea.

This paper postulates that the features of CSDB can be identified and they feel that although many central hypopneas are not "scored" using the current medical guidelines (the paper says "this remains a research option"), that CSDB can be identified.

The paper indicates that one characteristic of this "control dysfunction related disease" is that it improves during the REM phase of sleep.
Since sleep has distinct phases, it is interesting that this problem can appear as one type of problem in the early stages of sleep and then foster a different set of characteristics as one moves to REM sleep.

It's no wonder that standard PAP treatment can't do much for this problem - just throwing pressure at it all night long obviously isn't the fix.

The paper says that there are two types of complex disease
-- hypercapnic (where one has an excess of CO2 in the system)
-- and hypocapnic (where one has a deficiency of CO2 in the system)

The focus and scope of the balance of the paper is on cases who are deficient in CO2.

Nearer the end of the paper, it continues to say that minimizing the hypocapnia (e.g. deficiency of CO2 in the blood)is a critical component of any therapy for complex disease associated with CO2.

"Strategies include using the lowest pressure that allows reasonable control,
avoiding modalities that destabilize (continuous and bilevel pressure may be less or more effective in individual patients; automatic continuous pressure machines should be avoided), the use of a nonvented mask, the use of enhanced expiratory rebreathing space" (e.g. EERS) "and controlled increases of CO2 concentrations in the inhaled air."

The paper goes on to discuss non vented masks, EERS or dead space for rebreathing (e.g. a place for a controlled amount of CO2 to gather, changing the chemical mix of the respiratory control system -- my words not the paper).

Dead space is impractical without use of an appropriate machine, as the amount of space necessary to gather CO2 is signficant.
However with positive airway pressure, a reasonable length of tubing can suffice to create necessary levels of dead space.

The paper goes on to say

Dead space EERS + PAP as compared to just using EERS dead space alone
results in

"(i) Reduced rebreathing volumes are required; (ii) Continuous washout restricts effective dead space to expiration only (inspired CO2 does not increase), (iii) There is an absolute requirement for a very tight fit of the mask.[/b, (iv) Patients do not notice the added rebreathing space, which suggests that the positive pressure support counters this respiratory sensation.

There was also original work done with a positive airway pressure gas modulator (an experimental valve that provided flow independent and precisely controlled increases of CO2 in the inspired air.I don't know much about that but have heard of it.


My questions and observations:

1) Leaks are important factors in this type of treatment, because the amount of CO2 gathering in the dead space would be impacted by the leak.

2) In the home leaks are inevitable. The patient adjusts his or her own mask fit. They may toss and sleep either supine or on their sides.

3) Even with a full face mask, one can move their jaw or their cheeks and change the leak rate of the mask.(Maybe we need a chin restraint along with the FF mask.

4) Once you have a suitable interface device, and its leaks are not excessive, then what technique is of most helpful to resolving a given patients problems. Each patient reacts differently or has unique features of their respiratory control system, such that apneas or hyponeas are triggered differently.

Therefore, will the approach of the ResMed ASV or the Respironics HeartPap
be of more help to a given individual? And does the addition of CO2 i(and external oxygen) into the mix change the answer if neither quite help on a standalone basis.

This is the $50,000 question. The sleep lab must be well versed in CSDB, to
do what is necessary in a split night PSG, to simply identify it properly.
Then one must try machine / algorithm, pressure settings, external OX,
dead space if needed, and patient position.
No wonder we have to keep at it until someone tries the right set of variables to help our situation!

Okay, DSM. SAG. SMS, CQ, RG and FS its time to weigh in.

Have pity on us that must read the replies with a medical dictionary open

Lubman

[rested gal]

Well, I'll weigh in with this much -- in my non-medical opinion....

The sleep lab must be well versed in CSDB, to
do what is necessary in a split night PSG, to simply identify it properly.

I think everything else rests on that -- proper identification of what needs fixing. I personally don't think a split night PSG is the way to go if Complex Sleep Disordered Breathing is suspected at all.

I'm not a big fan of split night PSG's anyway. I think a full diagnostic data-gathering night is better even when dealing with plain OSA. I think a full baseline PSG night is even more important when it comes to trying to diagnose CSDB correctly.

[Lubman]

RestedGal
I think you are quite right. A full night test to characterize the problem and a full night to try and fix it is for most labs the way to go.

Lubman

[StillAnotherGuest]

Unfortunately, I still haven't used the Respironics AutoASV, so can't comment on head-to-head there.

Nor used an EERS system, or plan to, for a variety of reasons. As you mention, once you leave the laboratory, a variety of things could happen that render EERS useless, so you don't know if it's working effectively.

And we'll have to see what happens over a period of time. For instance, in the face of elevated pCO2, the body starts to retain -HCO3. Will this artificial nocturnal elevation of pCO2 in patients with EERS do that, and if so, will that change apnea threshold yet again? Is it only an acute elevation in pCO2 level that provides breathing stability?

Will the increased Work of Breathing associated with utilizing enhanced CO2 systems prove detrimental to those patients who have compromised cardiac status?

Will EERS apply equally well to CSDB? Most of the work in the past concerned patients with largely a CHF/CSR component, they were baseline hypocapnic (pCO2 in the mid- to high-30's, at most) and the necessary increases in pCO2 to achieve breathing stability were only about 1.3 to 3.0 mmHg. Will this apply equally to CSBD? As you can see in my example back there, that patient, a true CSBD, had a baseline pCO2 of low- to mid- 40s, basically normal or perhaps even slightly elevated. Does that mean that chemical responsiveness is the overwhelming culprit here?

Is the reason that enhanced CO2 works because cardiac is output now stabilized, leading to the chemoreceptors seeing more stable stimuli? Blood gets back to the right heart by the negative pressure associated with inspiration. It diminishes significantly during no chest movement (central apnea, note not obstructive apnea) and increases significantly during the resultant hyperpnea. Does it then progress in that the increased minute ventilation associated with EERS further increases venous return and consequently cardiac output, and now the circulatory delay component is addressed? Does a pressure support system (BiPAP or ASV, or even CPAP for that matter) then negate this?

Is trying to use a combined therapy (ASV plus EERS) then self-defeating? Will the ASV simply overcome the effects of the EERS as the patient responds (by hyperventilation) to the elevated pCO2? Should EERS be limited to CPAP (and maybe APAP) only?

Perhaps some of these questions will have some light shed on them when Drs. Gilmartin and Thomas present at the APSS Meeting on June 12:

Treatment of Complex Sleep Apnea

Co-Chairs: Geoffrey Gilmartin, M.D., and Robert Thomas, M.D.

OBJECTIVES:
Identify specific polysomnographic patterns of complex sleep apnea.
Outline appropriate monitoring montages for complex sleep apnea, including use of the End-Tidal CO2 signal.
List approaches to minimize hypocapnia during positive airway pressure titration.
Describe the unique challenges and polysomnographic patterns associated with the use of Adaptive Servo Ventilation.

Their abstract summarizes their first 54 patients utilizing ASV, how better results were gained with the use of EERS with ASV, and their experience with patient-ventilator dyssynchrony.

It will be interesting to see their definition of CompSAS, and one would expect that it would include central apneas. And also how they specifically define period breathing. Everybody is leaning towards persistent central apnea index (CAI) > 5 after treatment to define CompSAS, so I'm maintaining that if you have a central apnea index of "0" you don't have CompSAS, and if you don't have CompSAS or CSR, being put on an AdaptSV is a monumental waste of time and effort.

Further, there has to be careful patient selection where you want to even consider ASV. You can see in the Morgenthaler study their mean AHI post-CPAP treatment was 34.3. If the persistent CAI is only 5 to maybe about 20, one needs careful consideration before deciding to try AdaptSV, because runaways can create more problems than you fix. We'll have to see if Respironics AutoASV will do a better job here. But keep in mind, it's been out for about 6 years already, so if it's "Simply (More) Amazing", you'd think there'd be a little more fanfare by now.

Now, the ResMed approach to ASV (ventilate to 90% of target) is based specifically on central apnea (CSR). That it can be directly applied to CSDB may be a separate issue TBD, but it looks like that's gonna be OK too. But if you don't have central apnea in some shape or fashion, then this algorithm has nothing to do with what you have, and as soon as the thing goes into ASV Mode you can guarantee that it will overventilate and generate hypocapnia. Adding CO2 via EERS does not then treat the problem, it treats the solution. So, in a roundabout reply to your question, Lubman, I think that if you were going to look at EERS, you would have to see how it acts with plain old CPAP. If one can be successfully treated with EERS/CPAP, what's the sense of dragging out the ASV if you're saying that a big problem with AdaptSV is that it creates patient dyssynchrony? If it hurts to hit one's self in the head with a hammer, then, y'know?

Within most sleep software, you can generate trend graphs. In looking at EERS effectiveness, I would look at the CO2 trend (ETCO2, TcpCO2, whichever) to see how well the EERS is being maintained, at least in the laboratory. And perhaps look at the correlation between that and system leaks. Since you can track leaks with any PAP software, you would now get a good idea of EERS effectiveness, i.e., if you got excessive leaks all night, you got no effective EERS.

On Mask Selection

It looks like the ResMed Quattro falls into the list of accepted masks for use with AdaptSV. Let me just drag something in here from the Quattro thread, and that is, I don't think that Quattro will allow more CO2 retention, I think it will have the same characteristics as UMFFM. Further, I believe that mask selection has absolutely nothing to do with what your CO2 ends up to be because of mask exhaust qualities (as long as you don't "fix" it).

Now comes the inevitable exception. The only way that CO2 washout could make a difference in mask selection would be to somehow change what happens in the patient, namely, change the body's anatomical dead space, i.e., the air that exists in the oro-nasal pharyngeal space (nose and mouth, among other places). And the only way to accomplish that would be through the use of a full-face mask whose intra-mask characteristics created a purge of flow through the oro-nasal pharynx. With me so far? The air flow would come through the bottom of the mask and be directed at the patient's mouth. If the exhaust vents were located at the top of the mask, then there would be flow directed from the base to the top, and this would now include the purge of flow through the oro-nasal pharynx and Voila! CO2 washout of the anatomical dead space.

Now SAG did not invent this, this was studied elsewhere:

Mask Characteristics

Guess which masks have this quality?



and



Guess which masks are recommended for AdaptSV?

Why is CPAP Elves and Magic Fairy Dust a far more plausible explanation as to why ASV works?

I hope this clears everything up.
SAG

[rested gal]

Very interesting post, SAG.

You commented:
It will be interesting to see their definition of CompSAS, and one would expect that it would include central apneas. And also how they specifically define period breathing. Everybody is leaning towards persistent central apnea index (CAI) > 5 after treatment to define CompSAS, so I'm maintaining that if you have a central apnea index of "0" you don't have CompSAS, and if you don't have CompSAS or CSR, being put on an AdaptSV is a monumental waste of time and effort.

Further, there has to be careful patient selection where you want to even consider ASV.

Yep, I'll be especially interested to hear the BI guys' definition of CompSAS (CSDB) since the usefulness of their study results will depend on what their definitions were when selecting the 54 to include in the first place.

frequenseeker, do you know if your case is one of the 54?

[dsm]

SAG,

Many thanks for another well presented and interesting post.

I am hoping to trial a Quattro mask soon (plus a Liberty). My sleep clinic have them both but aren't using them (or lending them) until Resmed explain the proper process for cleaning between users (the hospital need this info as part of their official processes).

To Lubman - interesting post - I will read it again & post response.

Re the existing UMFF mask, I find it works for me but have found these steps need to be followed

- I wash the seal every day with soapy water & rinse & then dry the mask
- Before sleep I wash my face with soapy water & rinse (& dry)
- I replace the seal every 6-9 months (they do seem to go soft & leak more easily)

DSM

[Lubman]

SAG --

I'm with DSM, I have read it three times and need to try it once when I'm not tired -- oops it seems I'm generally tired, maybe I should read it at 4 AM ...

SAG, I am also eager to read the upcoming paper.
Where are the conference papers published?

I would like to try some comparison testing as you have some excellent points -- a baseline using say BiPaP or CPAP with EERS certainly would provide insight.

The one factor that is not "scientific" is a person gets used to the
"gentle" way ASV interacts with your breathing. It feels different than
getting hit in the head with high pressure from an xPAP.

Are you going to attend the June 12 conference?

Lubman

[StillAnotherGuest]

I am also eager to read the upcoming paper.
Where are the conference papers published?

Right now, I only know of the abstract...



SAG

[dsm]

For folks interested in this thread - this link is a *mast* read.
Padacheek provided it here ...

Very interesting ...

viewtopic/t20646/Complex-Sleep-Apnea-treatment.html

DSM

#2

The Summary part ...

SUMMARY

We remain very enthusiastic about ASV as our experience and our patient base expand. In our opinion, development of the Adapt SV represents a major step forward in the treatment of CompSA. This may be the most significant improvement in PAP therapy since the original development of bilevel therapy. We expect that numerous clinical trials (some undoubtedly already in progress) will further demonstrate the scope and limitations of this intriguing technique over the next several years. The role of ASV in CompSA may equal or in fact eclipse the usefulness of the device in CSA/CSR associated with CHF, which was the initial target market for the device.

Competition between device manufacturers also may encourage further improvements in the technology. On March 7, Respironics Inc, Murrysville, Pa, announced that the FDA granted 510(k) clearance to its BiPAP autoSV device for treating central and/or mixed apneas and periodic breathing. Other manufacturers will undoubtedly develop similar devices, too, in an attempt to capitalize on this market, which some investigators believe may be as large as 10% to 15% of the existing sleep apnea population. From our limited experience to date, we think these estimates may be high, although perhaps our current criteria for diagnosis are too stringent.

We have been pleased with our experience with the Adapt SV device and look forward to collecting experience with the BiPAP autoSV device and any other ASV devices that may enter the market. If your experience mirrors ours, you too will soon be able to say that this new technology makes many "complex" patients "simple."

Stephen E. Brown, MD, DABSM, is medical director of Memorial Care Sleep Disorders Centers in Long Beach, Calif. Also contributing technical assistance with the article were Kerry Kouchi, RPSGT; Tamera Godfrey, RPSGT; Heather Kronstedt, RPSGT; and Daniel Brennan, RPSGT. He and his colleagues may be contacted by e-mail at sleepeditor@ascendmedia.com.

[christinequilts]

Just a quick update~

I started having worse 'grading' on my leaks with my Adapt, even though the actual leak rates were not that bad for the last week or two. I couldn't figure out what was going on and tried changing masks, rerunning LC, etc, but no matter what I did, I couldn't get an 'Excellant' grade. Finally the other night I noticed an extra vent sound...darn cat had bit my hose. He has never bit an xPAP hose in almost 4 years time- its those darn plastic clips that hold the sensor line to the hose that he was actually biting at and he accidentally slipped & got the main hose-lol. Its a good thing that he's awfully cute and that Teflon plumbing tape fixed it up just fine. Guess I need to get around to washing/vinegar soaking my new hose so I can use...and order another backup one. It could have been worse...at least it didn't make it leak enough to make the leak alarm go off, which drives my dog crazy...who then decides to keep me awake so the leak alarm can't go off. Pets, you've got to love them

I'm really thankful for the Adapt- it seems I've developed an allergy to Motrin/NSAIDS now too. I didn't put it all together at first, thought I was coming down with a cold or seasonal allergies were worse when I woke up with a little wheezing in the morning 2 days in row and with my face a little more swollen then normal. I don't take Motrin very often, I had to limit it to 200mg 4-5 times per month, due to kidney situation. So when I didn't have any problems for a couple nights and then had the same problems again when I took Motrin again, it was pretty clear the Motrin was the cause- I didn't put it all together until the next morning of course. And as you would expect, my Adapt reported much higher average pressure those nights and lower Tidal Volume, BPM & MV. Hate to think what might have happened without it to help keep me breathing.

I'm still working on figuring out all the allergy stuff overall- its getting stranger & stranger. One good thing I did figure out is that NasalCrom spray was safe for me, since I had to stop using Nasonex. Even better, I found it could be used to help prevent & treat hives, even those cause from Pressure Urticaria. Usually it would be mixed with a lotion, but I mixed with an aloe vera distillate (like water) and spray it on the area my mask sits- and like magic, no more red marks in the morning from my mask. And more importantly, no more hives & blister-like hives from my mask. I've been using the same mask, Vista, for over a month now, without having to swap out to my Activa or other masks at all...usually I couldn't go more then a week or so with the same mask.

[jammin]

I'm about a month into my experience with the Adapt SV, and overall it's gone pretty well. After a week or so I gave up on the UMFF mask I started with because I couldn't overcome the leaks, which always seemed to worsen just as I would begin to doze off. It may not have been the best fit to start with, but that's another issue. I got the DME to sell me a Swift Nasal Pillow setup and have been more comfortable and successful with it. Though it has it's own leak issues, they seem more manageable, and I got the hint about taping the mouth closed from another thread here - that helped a lot. Of course, the Swift isn't approved for the SV, and I've noticed the posts above that talk about the recommended masks. Are any others using swift with the sv, and is there any significant downside to using it?

One other question: The backup respiration rate of 15 breaths per minute is way faster than I normally breathe when I'm resting. Is that an absolute unchangeable setting on the SV? Is it a minimum threshold for healthy breathing when asleep?

BTW, I accidentally posted this same message as a separate topic outside of this thread. Still getting the hang of this.

[christinequilts]

I'm about a month into my experience with the Adapt SV, and overall it's gone pretty well. After a week or so I gave up on the UMFF mask I started with because I couldn't overcome the leaks, which always seemed to worsen just as I would begin to doze off. It may not have been the best fit to start with, but that's another issue. I got the DME to sell me a Swift Nasal Pillow setup and have been more comfortable and successful with it. ... Of course, the Swift isn't approved for the SV, and I've noticed the posts above that talk about the recommended masks. Are any others using swift with the sv, and is there any significant downside to using it?

Personally, I would not use a Swift with the Adapt, nor any other mask that cannot pass the Learning Circuit on its own. How are you running LC with the Swift? Any time something is changed with circuit- different humidifier, new hose, different mask, etc, you have to run the LC so the Adapt can calculate the correct impedance of the circuit. There are several Adapt approved masks, UMFF, UMII-nasal mask, Activa nasal, Vista nasal (over end of nose, doesn't use bridge of nose), original Mirage & I think the new FFM from ResMed...I can't remember the name of it. I would try all of those before I would consider using a non-compatible mask, and then the mask still has to be able to pass the LC on its own.

One other question: The backup respiration rate of 15 breaths per minute is way faster than I normally breathe when I'm resting. Is that an absolute unchangeable setting on the SV? Is it a minimum threshold for healthy breathing when asleep?

The backup rate of 15 is a failsafe backup rate that only comes into play if the Adapt doesn't have enough information to base a floating backup rate on your own breathing. It also comes into play when a Swift is used with the Adapt- if you go back a few pages (around page 20, I think), you should come across a couple post on my experience of trying the Swift with my Adapt for just a couple hours...it wasn't a pleasant experience at all. I also do not like the UMFF- I used it for a few weeks prior to my Adapt titration and a week or so after, but since then, I've used either an Activa or Vista- with the Vista being my personal favorite.

Even the description from the article in this months Sleep Review touches briefly on what they call 'smart' backup rate

WHAT IS ADAPTIVE SERVO-VENTILATION?
ASV is a novel form of bilevel ventilation. The pressure provided during inspiration varies, increasing when the patient's tidal volume decreases, and conversely. This varying assist helps to regularize the chaotic pattern of respiration by reducing and then eliminating the alternating periods of patient over- and under-breathing. This feature operates rapidly, within two or three breaths (almost functioning like a rapidly acting adaptive PAP or A-PAP device). The ASV algorithm also monitors recent average minute ventilation (using the trailing 3-minute ventilation) and continuously calculates a target ventilation (90% of the recent average ventilation). This relatively weak, but persistent, downward constraining force on minute ventilation serves to minimize/eliminate the CO2 instability and raises the PaCO2 just enough to prevent the frequent CO2 dips below the apnea threshold. A "smart" backup rate is actuated automatically only if/when needed. The expiratory PAP or EPAP-equivalent is called the "EEP" (end-expiratory pressure) as the ASV waveform is "softer," meaning that it decreases more slowly during exhalation than traditional bilevel devices that have a near-square waveform. The default EEP is 5 cm H2O, and can be raised to a maximum of 10 cm H2O. The default pressure support (the inspiratory PAP or IPAP equivalent) is 3 cm H2O greater than the EEP, but can be adjusted upward if needed.

Since Minute Vent (MV) is the targeted measure for the Adapt, if it can't adjust to your breathing rate because of using the wrong type of mask, its going to give you suboptimal treatment. MV=Tidal Volume (VT- how much air you exchange or how deeply you breath) X # of breaths per minute. If one is held fairly constant, the other isn't able to move around as much and you're negating the Adapts function & are left with a BiPAP basically running in straight TIMED mode. I can breath fairly slowly, like 10 BPM, as long as I'm taking deep enough breaths, without my Adapt trying to get me to breath faster. If I'm breathing very slowly and not very deeply, then it works to get me to breath a little faster & deeper, to keep my MV consistent. Or if I'm breathing quickly enough, but not deep enough, then the Adapt will try to nudge me to breath deeper and possible a little faster to keep my MV at the target, based on my last couple minutes breathing.

BTW, I accidentally posted this same message as a separate topic outside of this thread. Still getting the hang of this.

You should be able to edit the post & delete it, I think...as long as you were signed in. Or if worse comes to worse, report your own post as Spam? I'm not sure. [/quote]

[christinequilts]

And we'll have to see what happens over a period of time. For instance, in the face of elevated pCO2, the body starts to retain -HCO3. Will this artificial nocturnal elevation of pCO2 in patients with EERS do that, and if so, will that change apnea threshold yet again? Is it only an acute elevation in pCO2 level that provides breathing stability?

Have there been any studies that look at EERS for SBD for more then a night or two in the lab? Anything that tracks pCO2 at home, over time? Lot's of things can look like they help in the lab, in preliminary studies, but don't pan out over time- like some of the medications they have suggested for apnea in the past or the pacemaker connection they thought they saw at one point.

Perhaps some of these questions will have some light shed on them when Drs. Gilmartin and Thomas present at the APSS Meeting...It will be interesting to see their definition of CompSAS, and one would expect that it would include central apneas. And also how they specifically define period breathing. Everybody is leaning towards persistent central apnea index (CAI) > 5 after treatment to define CompSAS, so I'm maintaining that if you have a central apnea index of "0" you don't have CompSAS, and if you don't have CompSAS or CSR, being put on an AdaptSV is a monumental waste of time and effort.

I sure hope we finally hear what their definition of CompSAS is, but its not clear in any of the stuff I've read from them so far. Do you think the CompSA definition will ever include patients like me, who have clearly central sleep apnea from the start that is persistent to treatment? Technically, I don't meet the definition of CompSA, since I've never had a obstructive AHI above 5 on any PSG.

Further, there has to be careful patient selection where you want to even consider ASV. You can see in the Morgenthaler study their mean AHI post-CPAP treatment was 34.3. If the persistent CAI is only 5 to maybe about 20, one needs careful consideration before deciding to try AdaptSV, because runaways can create more problems than you fix.

BI's patient selection alone could explain why: ASV use was associated with specific polysomnographic features when control was inadequate- continuous pressure cycling, single large breaths, and rapid consecutive breaths. These occurred with ASV alone in all but 8 patients, contributed to patient-ventilator dyssynchrony, and were eliminated by minimizing hypocapnia with EERS.
Could it be they are trying to use on too wide of a group that they only had 8 people out of 54 who did fine with the Adapt, without needing EERS? Just based on the reports Frequent posted, I think this could very well be one of there problems. Is anyone else seeing this dissynchrony in their Adapt patients? Or are they looking for another use for their EERS, since the Adapt has obviously put a dent in the potential patient population? Are other sleep labs using EERS for CompSA?

Couple other things I noted in the abstract:
ASV is the only currently approved therapy for central and complex SA.
Is it the only 'approved' therapy? Didn't the Morgenthaler study show other forms of xPAP may work appropriately for some patients with CompSA? Aren't other forms of xPAP approved to treat CompSA as well?

End expiatory pressure was adjusted to overcome obstruction.
Sure didn't look like did in Frequents Adapt titration to me...it will be interesting to see if her case if one of the 54 or not. Has anyone heard from her lately?

Additional oxygen was needed in 37 patients (66%)
Is that with EERS or ASV alone? It seems like a high percentage to me, but could it come back to 'treating the treatment' again?

Of course, I want to know which masks they used too...to me, if they used anything then the ResMed ones approved, that patients data is useless- especially if they used the Swift or any other mask that cannot pass the LC on its own. It almost seems to me, they should have used the UMFF for the purpose of the study. Also, does anyone else wonder what their results might be if they didn't try to titrate both the Adapt & EERS in one night? I know for me, there was definitely some adjustment period when I first started with my Adapt, and I had been using BiPAP ST for 3 years prior. I would think for the purposes of EERS addition, they would almost need to do a second nights study a few weeks later to allow the patient to adapt to the Adapt. One nights snap shot is not enough, IMHO. Especially if the person had been on straight CPAP prior.

We have to remember too, that presenting a study at conference isn't the same as submitting it to a peer reviewed journal. It will not have been evaluated as completely...it will be interesting to see when they finally do publish results. It's interesting they gave us so many other patient demographics (heart disease, use of sleep meds, etc), but never mentioned the severity of their apneas or anything else. I know personally that AHI isn't everything when it comes to CompSA, as periodic breathing and non-scorable events per Medicare guidelines left me with a fairly low AHI on my last PSG, before the Adapt, but then again, I had enough studies in the past that showed I had substantial CSA and other issues with sleep quality that were very obvious.

If it hurts to hit one's self in the head with a hammer, then, y'know?

...don't get a fancier hammer & expect it to hurt less?