[split] Off-Label ASV and Bilevel For UARS Therapy

[pareidolia]

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Moderator Action: Thread Split

This thread was split from a therapy thread by Idinks http://www.apneaboard.com/forums/Thread-...R-data-etc  There is value to the discussion of ASV vs bilevel therapies in the treatment of UARS, however in order not to disrupt the direct help intention with therapy threads, this debate has been split.

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It is possible, not likely, that the higher levels of PS typically required to treat UARS MAY trigger CO2 induced Central Apneas,

This is a contradiction, because any amount of Pressure Support applied on a breath by breath basis in the case of ASV will be measured specifically to resolve flow limitation and no more. (Definition of ASV algorithm) What you are saying is that resolving flow limitations by definition causes Clear Airway apneas. This is obviously not the case. In UARS the name of the game is to resolve flow limitation.

The machine of choice is the VAuto at this time.

Definitely not.

Some background reading for y'all: sleepbreathe.org/asv-and-bilevel-therapy-for-sdb-with-ifl/

[Gideon]

pareidolia, You sure you want to get into this?

1. The OP has very little CAI, Most users would call this a done deal.
2. Check out your breathing mechanics and drive.  You will find out that CO2 is the main driver of breathing.
3. Any form of CPAP increases the breathing efficiency of the user.  This includes increasing the flushing of CO2 from the body
4. PS/EPR tends to increase this faster than other settings.
5. In some susceptible individuals, this flushing of CO2 lowers CO2 concentration to below their apneic thresholds resulting in Central Apnea, 
6. after a period of not breathing because CO2 is below the apneic threshold, CO2 levels build up to above the apneic threshold and breathing resumes
7. This cycle often repeats many times.
8. The above occurs in a small percentage of individuals.  The only way we have to know is to see if it happens to an individual.
10. in this user, as noted above, the quantity of central apnea is low to a point where it does NOT need to be treated, watched yes, treated no.
11. Thus the machine of choice is currently a VAuto because this matching is designed to treat Flow Limitations associated with UARS, RERA, and the OSA that may be associated with it

Should the OP/User present with higher CAI to a point that it needs to be addressed
1. See what can be done to manage the CAI and Flow Limits, UARS, RERAS, and OSA.
2. Evaluate to see if an ASV should be sought for treatment. 
3. And ASV monitors and controls either Tidal Volume or Minute Vent depending on the brand.  It overcomes flow limits by monitoring and maintaining volume primarily by increasing the PS which is calculated on an individual breath based on a fairly brief sampling of the users breathing.

I do acknowledge that a particular clinic is utilizing ASV as the primary tool for treating UARS.

At this time the best matching for the OP is a ResMed AirCurve 10 VAuto

[SarcasticDave94]

Something that I've noted in members here on Apnea Board, ones that have some CA tendency but also have other obstructive based apnea and flow limits. If we attempt to address flow limits by raising Pressure Support, those CA will likely go up. Then if we address CA by lowering pressures and pressure swings, FL and other Obstructive events are likely to go up. Why? Because CA and OA/FL are on opposing ends of the see-saw.

I do hope this doesn't turn into an ASV for everyone tangent. Not everyone needs ASV, not if they expect to have insurance paying. And as is, most docs have trouble writing a script that says ASV even for those that do need it.

Anyway, I think it's pretty clear now the OP does not have indications of CA and ASV is not the correct machine of choice but that a VAuto is by far a better choice.

PS before it's asked, yes I know how an ASV works. A ResMed AirCurve 10 ASV is my current treatment machine.

[pareidolia]

1. The OP has very little CAI, Most users would call this a done deal.

We're not using the ASV to treat CAs, we're using it to minimize breathing effort as is relevant to UARS and FLs.

3. Any form of CPAP increases the breathing efficiency of the user.  This includes increasing the flushing of CO2 from the body

Not CPAP, but only bilevel modalities due to Pressure Support. Good thing ASV applies measured amounts of pressure support on a breath by breath basis to maintain (and not amplify) tidal volume, therefore preserving natural ventilation (ventilation is what laymen call "flushing CO2")

10. in this user, as noted above, the quantity of central apnea is low to a point where it does NOT need to be treated, watched yes, treated no.

Again, you fail to understand we are treating UARS here, not CSA.

11. Thus the machine of choice is currently a VAuto because this matching is designed to treat Flow Limitations associated with UARS, RERA, and the OSA that may be associated with it

For which ASV is even better equipped, thank you for making my point.

Something that I've noted in members here on Apnea Board, ones that have some CA tendency but also have other obstructive based apnea and flow limits. If we attempt to address flow limits by raising Pressure Support, those CA will likely go up. Then if we address CA by lowering pressures and pressure swings, FL and other Obstructive events are likely to go up. Why? Because CA and OA/FL are on opposing ends of the see-saw.

Exactly. The whole point of ASV is to keep the seesaw balanced by applying PS only when needed.

I do hope this doesn't turn into an ASV for everyone tangent. Not everyone needs ASV, not if they expect to have insurance paying. And as is, most docs have trouble writing a script that says ASV even for those that do need it.

Topic starter is in the UK, left to his own devices. That means that there will be no followup sleep studies to gauge the elimination of RERAs. If TS doesn't need dynamic PS, the ASV can be configured as a BiPAP S (Respironics allows for backup rate to be disabled, that is important)

If it turns out that TS needs dynamic PS, he will not regret not getting the ASV.

Anyway, I think it's pretty clear now the OP does not have indications of CA and ASV is not the correct machine of choice but that a VAuto is by far a better choice.

Again the same moot point repeated like a mantra.

PS before it's asked, yes I know how an ASV works. A ResMed AirCurve 10 ASV is my current treatment machine.

Using it doesn't necessarily equate to understanding, especially in the context of UARS. For UARS the Philips Respironics algorithm is more desirable anyway.

[Crimson Nape]

pareidolia - Are you basing your answers on fact or opinion? If it is fact, please list the references that you are using.

[Gideon]

1. The OP has very little CAI, Most users would call this a done deal.

We're not using the ASV to treat CAs, we're using it to minimize breathing effort as is relevant to UARS and FLs.
Here we are treating UARS and FLs, NOT CAI.  I was pointing out that we are NOT treating the CAI. (fb)

3. Any form of CPAP increases the breathing efficiency of the user.  This includes increasing the flushing of CO2 from the body

Not CPAP, but only bilevel modalities due to Pressure Support. Good thing ASV applies measured amounts of pressure support on a breath by breath basis to maintain (and not amplify) tidal volume, therefore preserving natural ventilation (ventilation is what laymen call "flushing CO2")
Yes CPAP, especially with ResMed and EPR which does offer "bilevel modalities due to" its implementation of EPR. If CPAP does not improve breathing efficiency why do we use it at all. Pure CPAP does improve breathing by reducing obstructive events. (fb)

10. in this user, as noted above, the quantity of central apnea is low to a point where it does NOT need to be treated, watched yes, treated no.

Again, you fail to understand we are treating UARS here, not CSA.
As I clearly stated above, "the quantity of central apnea is low to a point where it does NOT need to be treated"  You are the one that is failing to understand. (fb)

11. Thus the machine of choice is currently a VAuto because this matching is designed to treat Flow Limitations associated with UARS, RERA, and the OSA that may be associated with it

For which ASV is even better equipped, thank you for making my point.
The current data is insufficient to warrant an ASV at this time.  You or the OP are certainly open to disagreement and persue the ASV option. (fb)

I frequently recommend ASV when the data supports it.  It does not do so here yet.
BiLevel is the most common treatment for UARS.   I standby my recommendations. (fb)

[pareidolia]

It is a fact that the main problem of UARS is increased respiratory effort (RE in RERA) due to airway resistance (R in UARS).  (Masri, T. J., & Guilleminault, C. (2013). Upper Airway Resistance Syndrome. Encyclopedia of Sleep, 269–274. doi:10.1016/b978-0-12-378610-4.00320-x Guilleminault, C., & Los Reyes, V. D. (2011). Upper-airway resistance syndrome. Sleep Disorders, 401–409. doi:10.1016/b978-0-444-52006-7.00026-5 Arnold, W. C., & Guilleminault, C. (2019). Upper airway resistance syndrome 2018: non-hypoxic sleep disordered breathing. Expert Review of Respiratory Medicine. doi:10.1080/17476348.2019.1575731 )

It is a fact that bilevel modalities provide Pressure Support and that Pressure Support decreases work of breathing. Pressure support is useful for many conditions such as COPD, paralysis, weaning from full blown ventilation: (medscape.com/answers/304068-104794/what-are-the-advantages-of-pressure-support-ventilation-psv-to-wean-patients-from-mechanical-ventilation)

It is a fact that ASV (in the case of Philips Respironics) is a non-strict superset of BiPAP S. I.e. the ASV can be configured to act like a BiPAP S if necessary. (Clinical manual for PRS1 960 or DSX900)

It is a fact that restriction in UARS can vary analogously to the obstruction in OSA varying throughout the night. In the latter case APAP is applied. (Efficacy of auto-CPAP in the treatment of obstructive sleep apnea/hypopnea syndrome. J C Meurice , I Marc , and F Sériès doi:10.1164/ajrccm.153.2.8564134 )

It is a fact that flow limitation will decrease inspiratory flow peak amplitude, which is acted on by ASV, at least by the Philips Respironics implementation (sleepbreathe.org/asv-and-bilevel-therapy-for-sdb-with-ifl/)

[SuperSleeper]

pareidolia, could you please fill out your user profile with your specific machine information?  You've been here since 2017, so if you're still a CPAP user, that would be great if you could fill it all out properly.  Or if you're not using CPAP currently, simply put "not using CPAP" in those fields instead of "unsure".

Here's the link to edit your profile information:

http://www.apneaboard.com/forums/usercp....on=profile

[Sleeprider]

As you can see I split this discussion into a separate thread so we can discuss alternative approaches to treating UARS without diverging from the intention of the therapy link by Idinks. The discussion was certainly between ourselves and not directed to the individual requesting therapy help.

Bilevel and ASV are being advocated by Dr. Barry Krakow, for treatment of UARS and sleep apnea, however he does not exclusively recommend ASV over bilevel, and uses a case by case assessment. We have suggested the use of ASV from time to time to deal with more severe cases of flow limitation that is not resolved by EPR or bilevel pressure support alone, or where flow limitation and therapy onset of CA is a high risk. We often see flow limitation intermingled with CA when CPAP therapy is introduced. Both bonjour and I have considered or recommended the use of ASV in these cases.

The idea of using adaptive pressure support seems most appropriate to very severe cases of UARS; I have called them, "crushed cars" from the extremely flow limited inspiratory wave form. We get people showing up on the forum claiming to have UARS, that clearly have either mild cases, and they resolve flow limits using the limited pressure support of EPR with the Airsense 10 CPAPs. Others do great with 4 to 6 cm pressure support using the Vauto. When flow limitation does not resolve with up to 6 cm pressure support, or individuals experience CA events with EPR or pressure support, we are getting into the cases that may be appropriate for ASV. I realize there are advocates of ASV for everyone, but we have seen it is absolutely not appropriate for most people that don't need it, and it can be quite disruptive to sleep quality.

It is also important to be aware of the high cost and low availability of these machines. Getting a prescription for ASV is difficult enough, let alone using it for the "off-label" application of treating UARS. I could be the biggest fan in the world of using ASV for UARS, but I have no clue how to go about getting a prescription for that, and this quickly becomes self-funded, self-treatment which is not feasible for everyone. Idinks specifically stated a sensitivity to costs. I look forward to more discussion here, but hope it takes a different direction of advocating ideas of how and when to apply therapy alternatives, rather than a war of quotes.

[SarcasticDave94]

...

Something that I've noted in members here on Apnea Board, ones that have some CA tendency but also have other obstructive based apnea and flow limits. If we attempt to address flow limits by raising Pressure Support, those CA will likely go up. Then if we address CA by lowering pressures and pressure swings, FL and other Obstructive events are likely to go up. Why? Because CA and OA/FL are on opposing ends of the see-saw.

Exactly. The whole point of ASV is to keep the seesaw balanced by applying PS only when needed.

I do hope this doesn't turn into an ASV for everyone tangent. Not everyone needs ASV, not if they expect to have insurance paying. And as is, most docs have trouble writing a script that says ASV even for those that do need it.

Topic starter is in the UK, left to his own devices. That means that there will be no followup sleep studies to gauge the elimination of RERAs. If TS doesn't need dynamic PS, the ASV can be configured as a BiPAP S (Respironics allows for backup rate to be disabled, that is important)

If it turns out that TS needs dynamic PS, he will not regret not getting the ASV.

Anyway, I think it's pretty clear now the OP does not have indications of CA and ASV is not the correct machine of choice but that a VAuto is by far a better choice.

Again the same moot point repeated like a mantra.

PS before it's asked, yes I know how an ASV works. A ResMed AirCurve 10 ASV is my current treatment machine.

Using it doesn't necessarily equate to understanding, especially in the context of UARS. For UARS the Philips Respironics algorithm is more desirable anyway.

Part 1 about the see-saw I mentioned was only applicable in those with CA on one side and other apnea  on the other side. This comment of mine had nothing to do with UARS.

Part 2, things such as left to their own devices is pretty much where everyone is, from getting any PAP device to treating CA, let alone UARS. It's not limited to one place on the planet, UK, US or elsewhere. There may be a single sleep study, proof of apnea, which gets labeled obstructive and everyone gets CPAP. Unless the patient pushes for it, there's no follow-ups except what the insurance requires. Most patients do not request more studies, more discussions or follow-ups. Most either pass or fail at stage 1 so to speak. And most doctors and test technicians get things wrong so many times, that most do no get the diagnosis, the machine choice, the pressure setup correct as is. From various apnea patients I'm helping here, I'd say 9 of 10 are prescribed inaccurately, are set on wrong pressures, or given the wrong machine. And these same doctors rarely see CA or know how to treat it if they do in fact see it. Now you want these doctors to consider UARS? The chances they bungle this is near 100%.

The ASV I have, a ResMed AirCurve 10 ASV cannot be run in S mode. It has CPAP, ASV, and ASV Auto. And when my ASV is in CPAP it's straight plain CPAP, tending to be a poor CPAP substitute for an actual CPAP. But my ASV isn't intended for CPAP users, so it's understandable that this ASV makes a poor substitute for CPAP.

You mention Respironics. The Respironics does typically have more controls than a ResMed, in part because Respironics is slow, running outdated algorithms that give at best moderately acceptable therapy. As I recall, Respironics is using a basically unaltered algorithm from their machines 2 generations ago. They need manual control to do what ResMed does via algorithm. On any level of PAP machine, ResMed not Respironics, gives better therapy.

Now as on the subject that use isn't understanding. The RT at Apria that issued my ASV that I had to fight the doctor to get; this very knowledgeable medical RT had to guess at my ASV settings. She did not know how to interpret the script data into settings for my ASV. Want to guess who did know how to set it up? Me. I looked at the clinical manual, and I also looked at my script copy. Little ole me configured my ASV. I advocated for my need, my high level of CA required an ASV. I had to fight for months to get the machine designed for CA treatment. I did a month long self-titration, as the tech, the doc, and the RT all concluded wrong settings would treat me well.

And now we come to one last area. And this will be important for a whole lot of people. This goes back to the area where patients are left to their own devices. I mentioned the difficulty in patients getting the machine paid for by insurance. My ASV to treat CA as one example. You need to convince doctors and insurance companies to pay for the ASV to treat UARS. An ASV may in fact work to treat UARS. Who is going to pay for the ASV to treat UARS? Few patients pay for the machine they get for the treatment the machines are designed for. Quite a number of members here have recently bought their own VAuto, or ASV, or even CPAP as the doctor refuses to prescribe for a clear need. Most doctors, sleep doctor or otherwise, few see CA and fewer know how to treat that rather basic idea of CA. You have a big uphill battle if you want doctors and insurance onboard with ASV treating UARS. You might be right that an ASV does treat UARS. However, do not assume that it will be accepted very well. I'll mention CA and the ASV again, most doctors still don't know how to treat it or prescribe one to treat CA properly. You are free to tackle your windmills as you see fit, but on this forum we require respect to all who's a member here.