Resmed VPAP Adapt SV - for Central Sleep Apnea

[StillAnotherGuest]

My brother is going into BI tomorrow for a sleep study with the Respironics vs ResMed ASV.

Course, you could always try the Malibu:

The Other AutoBiPAP
SAG

[christinequilts]

From your previous post:

I will ask about the CO2 levels specifiying the values as SAG noted.

I was wondering if you've had a chance to look up what a normal end tidal CO2 is range is & what the cut off is before its 'too high' yet? I am sure since you are a nurse, you have ready access to normal ranges for various medical measurements, so you do not have to rely on SAG's word alone. I'd like to hear what you've found out.

that is occurring due to the use of the Swift, and/or the nonvented EERS configuration with the Swift.

That is my take on it...the same as its been for several months. Added to the issue you don't appear to have any central disorder for the Adapt to treat in the first place, only REM dominant OSA, from the PSG reports you have posted. Plus it appears you were never really titrated on the Adapt to treat OSA, which seems unusual to me. I guess I still understand what the EERS was treating when they added it.

I still have yet to experiment and report back on Vista vs Swift (both nonvented/EERS setup) - will do soon.

I'm surprised you haven't done that yet, I would have thought you would have returned the Adapt to your DME by now since it doesn't work for you and you have such a high monthly copay. Is there some reason you're keeping it? I would think your insurance would not want to continue to pay for a machine you can't use/aren't using.

My brother is going into BI tomorrow for a sleep study with the Respironics vs ResMed ASV.

I take it your brother is also not doing well on the Adapt? Is it due to using the Swift, as you were? Have you shared with him what we've learned about the Swift and had him try his Vista to see if he could feel a difference even for a short 20-30 minute test while awake?-especially immediately after running LC. What did his original PSG show were his main issues, obstructive or central apneas?

There has been extensive discussion here about the technical differences between the two. I am wondering, could someone put together a summary of the conclusions here?

The most important conclusions about ASV overall have been:
1. You have to know what you treating before you treat it....but that goes with any aspect of sleep medicine and any type of machine, period.
2. You have to have central disordered breathing to benefit from ASV technology...it doesn't do anything for obstructives that strait CPAP can't do...and may even do worse.
3. The Adapt is mask specific and no masks that severely restrict air flow should be used with it.
4. Doctors have a lot to learn about ASV and not all of them are aware of basic treatment parameters, let alone how or why it 'works' yet.

To the Respironics machine in particular, there is a lot of unknowns still and I don't think we have reached any solid conclusions yet, based on the information we have. We each have our own personal opinions, which we have developed by reviewing the limited information and by discussing what we have learned amongst ourselves. My personal opinion is that there is still a question of how exactly its going to treat centrals compared to the Adapt. As it stands now, it sounds as if its not going to do anything to adjust breathing rate other then strait backup rate and its only looking at how much air is exchanged (peak flow), adjusting pressure accordingly. Personally, it makes me wonder if it will work as well in cases like mine where I'm in either in periodic breathing patterns or having full blown central events most of the night without the Adapt. Would changes in pressure alone be able to preemptively strike to prevent centrals? Or would I be left with a fixed backup rate and a high pressure blowing most of the night, which would surely lead to increased mask leaks & even possible mouth leaks. Is it really new technology, like the Adapt was, or is it a marriage of existing technology from the BiPAP ST & autoBiPAP? If its the later, we have to remember that well BiPAP ST may have been the best treatment for severe centrals until recently, it wasn't always that successful in all cases and was primarily reactive, not preventative treatment; and autoBiPAP was designed to treat obstructive events, not centrals.

Here is my take on the marketing claims they've made:

• Algorithm works on minute vent vs peak flow. One includes a measure of volume & RR, the other only air exchange, which I noted above.
  
  Adaptive phase vs no adaptive phase- the 40 minute adaptive phase is up to 40 minutes with the Adapt, and is not necessarily that long in most cases, and is much shorter in most cases. There may be slightly more adaptive phase after running LC, but that doesn't need to be done nightly in most cases and with compatible masks, I cannot tell a difference in how it feels then as I could with other masks. One could also turn the statement around and say if the the autoSV doesn't have an adaptive phase, then it doesn't adapt to the user, which makes it less ASV like.
  
  Normalization of breathing after 10-40min vs 2-6min. I'd have to see it for my own eyes before I'd believe that marketing claim. Changing pressure only with a fixed backup rate will only do so much, IMHO. I know how often I completely ignored my Synchrony when it went into timed mode for more then a minute or more while asleep. What do they define as 'normalization of breathing' in the first place? Is it absence of the need for additional pressure support by the machine? That brings us back to what measures the algorithm uses again.
  
  One mode (min BiPAP+PS) vs different modes (CPAP, CPAP+PS, BiPAP, BiPAP+PS). First off, the Adapt has 2 modes, it also functions in CPAP mode so that claim makes no sense other then poor sportsmanship. Second of all, why would someone pay for that advanced of a machine only to use in CPAP or regular BiPAP mode? And will CPAP+PS even be useful, let alone qualify for insurance coverage? (and did anyone else notice they said the Adapt has BiPAP+PS...not BiLevelPAP+PS? Are they finally caving on the BiPAP name issue?-lol)
  
  One mask type recommended (FFM) vs all masks types can be used. First issue, apple to oranges- recommended vs used. We don't know what the recommendations are for the autoSV as of yet, but a good guess is going to be only Respironics masks at minimum, maybe even more specific for optimal performance. The Adapt has several different mask that are fully compatible, not just FFM; though FFM are recommended overall for all BiPAP users because of the issue of mouth leaks, which it seems the autoSV is going to be more susceptible to with relying on pressure support only. Even I have occasional mouth leaks with my Adapt when it gets up to the top pressure range as quickly as it does with a high EPAP/IPAP spread.
  
  Leakage compensation up to 24l/min vs 60l/min. Is the 60 including intentional mask vent leaks or not? If 24 is the cutoff, why is the mask leak alarm on the Adapt set for 30L/min? And why was my mask fit rated as excellent this morning when I had an average leak of 26L/min? And if you're really leaking 60L/min, it doesn't matter what the machine is doing for the most part because you are not getting the full benefit. Plus the leakage compensation of the Adapt is tailored to each individual mask, by selecting the appropriate mask where it sounds as if the autoSV will be guessing at mask leak rates, as have other past Respironics machines.
  
  Pressure Ranges- too much apples & oranges again. Besides, the autoSV may have higher ranges available, but who really needs an EPAP of 25?..or wants it? Especially if they are prone to central events. Bigger is not always better.
  
  Backup rate fixed at 15 vs auto+fixed. We know from reveiwing the Adapt literature that the backup rate of 15 is a failsafe backup rate, which is very different then a fixed backup rate of 15. So this is another apples & oranges comparision.
  
  OSA has to be titrated on both machines, though it sounds like both the EPAP & IPAP has to be determined by titration, with the lowest EPAP available being 4. ResMed realized most people don't do well with only 4cm H2O, so they started with a more reasonable 5 preset. For most people, the preset EEP of 5 is adequate to address their obstructive component, so the Adapt could be used without a full titration if the person had enough indications for need and was unable to have a full PSG- like a heart patient in the hospital for example.
  
  CSA-CSR algorithm=automatic for both...but that doesn't mean they are equal in how effective they are no matter what the bench studies showed for FDS approval, so we can't call it equal. The autoSV is targeted towards OSA with secondary CSA or CSR, which is different then the Adapt being targeting towards CSA/CSR primary. I think it will be interesting to see if it gets coverage by Medicare as a ST, since the requires are fairly strict, especially in the CPAP+PS mode. That is an issue my own sleep doctor has brought up about the Adapt- that eventually all insurance companies are going to question why so many people suddenly need a $6000 machine instead of a $1200 one, especially if their primary Dx is OSA and the insurance may have already paid for one or more machines. Even in my case, he wants to make sure all the i's are dotted & t's crossed to make sure there is no question it was medically necessary for me. And mine was merely a machine swap out of same class of machine since I was already on BiPAP ST, with 3+ years of documentation to support its use.

I'm in no hurry to give it a test drive, as much as I desperately need more flexibility in mask options due to developing hives & welts from pressure of the mask. I want to wait until more information comes out about how it works, especially in comparison with the Adapt before I would consider it, from what I know at this point. I noticed in all of Respironics marketing PR, they made many comments about how it worked differently then the Adapt and may have some limited advantages, but there was no mention of how well it worked except for one extremely small study of like 6 patients with CSR. Even the one overseas brochure I located listed several studies, but all but one were on how CPAP improved CSR, not the autoSV. Seems like strange marketing to me.

[dsm]

Christine Quilts,

Your summary comes across to me as well thought out and insightful.

Good post

DSM

[frequenseeker]

Tidbits from my brother's sleep study experience:

There is a version of the ASV that will do Learn Circuit with the Swift now, but still not with EERS setups.

My brother was titrated on the new Respironics in some sort of Bipap mode and apparently it went well. His apneas were obstructive and mixed.

The secrecy with which both ResMed and Respironics isolate key information is a big problem for those who are trying to figure out the machines and how to help patients with them.

Of the group, Dr. Thomas has been working intensively with the machines and the use of them, including alot of lab time at night. He and other doctors were in attendance at the study.

The ResMed Adapt has had very limited success, hindered by the backup rate among other things.

disclaimer: this report is thirdhand.
frequenseeker

[frequenseeker]

Also, at my brother's recent sleep study, everyone was very impressed how well his DIY mouthleak preventing oral appliance worked. He had no mouthleaks at all and had a good study.

In his previous study (before he took my advice and made one) mouthleaks were a constant interference, despite chinstrap, lateral positioning, and other measures; they finally gave him a full face mask which helped him get a couple of hours of sleep. They were able to see flow limitation and periodicity and need for EERS but the ASV titration activities were limited.

frequenseeker

[Lubman]

FQ and CQ,

I am convinced that the non vented masks would benefit from a chin "guard" like on the F&P FF mask. When a ResMed FF mask is properly secured, not too tight, but not leaking around the sides -- the bottom can leak simply if one moves their mouth and chin a bit.

This is not the mouth leaks FQ was talking about with nasal masks, but it is also a consideration.

The idea of using a non vented mask with a separate chin strap doesn't sound too ideal to me.

There is a version of the ASV that will do Learn Circuit with the Swift now, but still not with EERS setups.

Would this be the ASV revision that DSM was talking about, that also would report indices? If so, when did it get US market approval?

Lubman

[StillAnotherGuest]

Pentobarbital Sedation Increases Genioglossus Respiratory Activity in Sleeping Rats SLEEP 30 (4) 478-488
Magdy Younes, PhD; Eileen Park, BSc; Richard L. Horner, PhD

Objective:
To determine whether certain sedatives may, by increasing arousal threshold, allow pharyngeal dilator muscle activity to increase more in response to chemical stimuli before arousal occurs.

Design, Participants and Interventions:
Thirteen chronically instrumented rats were studied during sleep following injections of placebo or sedating doses of pentobarbital (10mg/kg). Intermittently, inspired CO2 was increased gradually until arousal occurred.

Measurements and Results:
Maximum genioglossus activity reached before arousal was higher with pentobarbital than placebo (34.5 ± 24.3 vs 3.7 ± 2.9mV; P<0.001) for 2 reasons. First, genioglossus activity was greater during undisturbed sleep before CO2 was applied (23.3 ± 15.3 vs 2.5 ± 1.5 mV, P<0.001). When sleep periods were long, a ramp-like increase in genioglossus activity (GG-Ramp) began and progressed until arousal. GG-Ramps developed with both placebo and pentobarbital but reached higher levels with pentobarbital due to longer sleep periods and faster increase in genioglossus activity during the ramp. GG-Ramps began when diaphragm activity was lowest and progressed despite unchanged diaphragm activity. Second, as hypothesized, the increase in genioglossus activity with CO2 before arousal was greater than with placebo (11.2 ± 2.5 vs 1.2 ± 2.5mV; P<0.05) due to increased arousal threshold. In 27 of 126 CO2 challenges delivered while GG-Ramps were in progress, genioglossus activity paradoxically decreased despite increased diaphragmatic activity. These negative responses occurred randomly in 7 of 13 rats.

Conclusions:
In rats: 1) Sedatives may allow genioglossus activity to reach higher levels during sleep. 2) A time-dependent increase in genioglossus activity occurs during undisturbed sleep that is unrelated to chemical drive. 3) Transient hypercapnia may elicit inhibition of genioglossus activity under currently unidentified circumstances.

[Snoredog]

unidentified circumstances?

[christinequilts]

The ResMed Adapt has had very limited success, hindered by the backup rate among other things.

Is that at BI only? Could it be due to patient selection? And use of non-vented masks, EERS & non-compatible masks?

Everything I've heard regarding the Adapts use with its intended population has been pretty positive. Journal Sleep had an article from Mayo in April that showed ASV is very effective in treating patients with significant AHI's from CSA or CSR. I think its pretty safe to assume they used the Adapt, given its publication date was prior to the Respironics machine being FDA approved and the length of time it takes for research to occur & be published. Plus its the same research they reported at the May 2006 American Thoracic Society conference.

Adaptive Servoventilation Versus Noninvasive Positive Pressure Ventilation For Central, Mixed, And Complex Sleep Apnea Syndromes

Rationale: Although continuous positive airway pressure (CPAP) is most often effective in patients with obstructive sleep apnea, optimal treatment of patients with predominantly mixed apneas, central sleep apnea syndrome/Cheyne-Stokes respiration (CSA/CSR), or complex sleep apnea (CompSAS) is less straightforward, and may require alternative ventilatory assist modalities.

Objectives: To compare the efficacy of noninvasive positive pressure ventilation (NPPV) with adaptive servoventilation (ASV) in treating patients with centrally mediated breathing abnormalities. We hypothesized that NPPV and ASV would be equivalently efficacious in improving the apnea/hypopnea index (AHI) and respiratory arousal index (RAI).

Methods: Prospective randomized crossover clinical trial comparing NPPV with ASV in patients with CSA/CSR, predominantly mixed apneas, and CompSAS in an acute setting.

Measurements and Main Results: 21 patients (6 with CSA/CSR, 6 with predominantly mixed apneas, and 9 with CompSAS) with initial diagnostic AHI ± standard deviation 51.9 ± 22.8/hr and RAI 45.5 ± 26.5/hr completed the study. Following optimal titration with CPAP (N="15)," disturbed breathing and disturbed sleep remained high with mean AHI= 34.3 ± 25.7 and RAI="32.1" ± 29.7. AHI and RAI were markedly reduced with both NPPV (6.2 ± 7.6 and 6.4 ± 8.2) and ASV (0.8 ± 2.4 and 2.4 ± 4.5). Treatment AHI and RAI were both significantly lower using ASV (P <0.01).

Conclusions: These data confirm that in patients with CSA/CSR, mixed apneas, and CompSAS, both NPPV and ASV are effective in normalizing breathing and sleep parameters, and that ASV does so more effectively than NPPV in these types of patients.

***20+ patients starting average AHI was 52 with RAI of 46.
***For the 15 patients who CPAP was appropriate, it only reduced the average AHI to 34 & RAI to 32.
***Both NPPV & ASV lowered the average AHI/RAI
***NPPV average AHI was 6 & RAI 6 and
***ASV average AHI was less then 1 and RAI just over 2
I'd say that's pretty successful treatment, compared to the starting AHI average of over 50, wouldn't you? But again, all their subjects had significant central events to start with or that were apparent upon CPAP titration for the Adapt to treat. It has to have something to work with, some level of abnormal central events to identify a pattern to adapt to in the first place. I really don't see it being that successful if someone only has a few random central events, IMHO.



Here's an article from the UK from a year ago comparing ASV & Deadspace, which showed increased sleep fragmentation with deadspace but not with ASV (research also done with ResMed AutoSet CS/Adapt SV):

Adaptive servo-ventilation and deadspace: effects on central sleep apnoea
Journal of sleep research (England) Jun 2006, 15 (2) p199-205

Central Sleep Apnoea (CSA) occurs commonly in heart failure. Adaptive
servo-ventilation (ASV) and deadspace (DS) have been shown in research
settings to reverse CSA. The likely mechanism for this is the increase of
PaCO(2) above the apnoeic threshold. However the role of increasing FiCO(2) on arousability remains unclear.

To compare the effects of ASV and DS on sleep and breathing, in particular effects on Arousal Index (ArI), ten male patients with heart failure and CSA were studied during three nights with polysomnography plus measurements of PetCO(2). The order of the interventions control (C), ASV and DS was randomized. ASV and DS caused similar reductions in apnoea-hypopnoea index [(C) 30.0 +/- 6.6, (ASV) 14.0 +/- 3.8, (DS) 15.9 +/- 4.7 e h(-1); both P < 0.05]. However, DS was associated with decreased total sleep time compared with C (P < 0.02) and increased spontaneous ArI compared to C and ASV (both P < 0.01).

Only DS was associated with increased DeltaPetCO(2) from resting wakefulness to eupnic sleep [(C) 2.1 +/- 0.9, (ASV) 1.3 +/- 1.0, (DS) 5.6 +/- 0.5 mmHg; P = 0.01]. ASV and DS both stabilized ventilation however DS application also increased sleep fragmentation with negative impacts on sleep architecture. We speculate that this effect is likely to be mediated by increased PetCO(2) and respiratory effort associated with DS application.

[jammin]

Christinequilts, first I want to thank you for all the helpful information you post here. I tried cpap six years ago, failed dismally and gave up. I recently had to startup with a new primary care doc who insisted on a new sleep test when he saw apnea in my history. The first of three new tests revealed that I was still having apnea episodes, which I was in complete denial about since I'm mostly asymptomatic during the day, and most of my episodes were central, as in my studies from 2001. The sleep doc said my oxygen saturation was falling all the way to 67% during the night, and she wanted me to start on a bipap plus an oxygen concentrator. Based mostly on what I've read here, I asked for and got another study on an adapt sv. I haven't yet seen the full report from that study but during it my waking oxygen concentration was 93% and with the asv it never fell below 91% while asleep. The study with the asv was the only one I've had that wasn't a completely miserable experience. Next week Praxair is bringing out an adapt sv for me, and I'm psyched up to give this a good try. No doubt I'll have questions and I'll be asking for help here.

Here's a request. In sifting through the reams of good information here, it's quite a struggle for a newbie to figure out some of the acronyms. If there is a glossary of them could someone point me to it, and if there isn't could some kind hearted soul consider making one?

[rested gal]

Here's a request. In sifting through the reams of good information here, it's quite a struggle for a newbie to figure out some of the acronyms. If there is a glossary of them could someone point me to it, and if there isn't could some kind hearted soul consider making one?

Here ya go, jammin...

Types of machines:
viewtopic.php?p=56836
"Whats the differences in BIPAP, XPAP, APAP, CFLEX"

christinequilts' excellent description of the ASV (Adaptive Servo Ventilation) machine to treat Central Sleep Apnea rather than Obstructive Sleep Apnea:
viewtopic.php?p=162266


Common abbreviations and definitions:
viewtopic.php?t=14902
"Learning lexicon of cpap terms"


Must reading for anyone who wants to take a large role in his/her own OSA treatment:

http://www.smart-sleep-apnea.blogspot.com
Mile High Sleeper's great information resource for cpap users.

[jammin]

Many thanks, rested gal

[frequenseeker]

Rested Gal to the Rescue! (can you say that very fast 10 times?! )

Christinequilts, the two studies you cited were of very sick individuals.

ten male patients with heart failure and CSA

and in the other there is no control for how much the cpap might be contributing to the CSA and CSDB.

Your conclusion

It has to have something to work with, some level of abnormal central events to identify a pattern to adapt to in the first place.

is astute (in other words, correct).


I am in the midst of more enlightening communications with the BI doctors. I will report soon. I'll give you a hint: the root of the problem is not the symptoms and the treatment is only tangentially PAP and machines.

frequenseeker

[christinequilts]

Christinequilts, the two studies you cited were of very sick individuals.

I'll agree the deadspace study was done on patient with more severe problems as there has been nothing published on its use in patients with mild apnea to start with. It was done in England, where the Adapt is used primarily for cardiac reasons only, not central sleep apnea alone, let alone CompSAS/CSDB.

As for the first study: 21 patients- 6 with CSA/CSR, 6 with predominantly mixed apneas, and 9 with CompSAS, diagnostic AHI 51.9. Is that that far from the realm of possibility? I had an original AHI of 63, 61.5 central & 1.5 obstructive and I know a lot of others here who have similarly high AHI's, some who were diagnosed as Mixed Apnea originally. Considering NPPV brought their AHI down to 6.2, on average, with only a very small percentile (1 patient?) being a full standard deviation above at 13.8 on NPPV, I'd say they were a fairly typical mix of Mixed Apnea, CSDB & CSA/CSR patients, not 'very sick individuals'.

[christinequilts]

Here's a request. In sifting through the reams of good information here, it's quite a struggle for a newbie to figure out some of the acronyms. If there is a glossary of them could someone point me to it, and if there isn't could some kind hearted soul consider making one?

Hopefully the links Rested Gal posted helped you out- I've been gone from the board for the last week or so. Have you received your Adapt yet? Let us know when you do and if you have any questions.