[Treatment] ASV Versus Other PAP Machines

[Greggory]

My Sleep Study Data
Sleep Profile:  Total time in bed was 8 hours and 10 minutes; total sleep time was 4 hours; sleep efficiency of 49%. Sleep onset latency was 15.0 minutes.  Stage N1 was 6.4%; stage N2 was 74.8%; stage N3 was 0.0%; REM sleep was 18.8%. 
 
Respiratory Profile:  There were 4 total apneas of which 3 were central apneas.  The patient’s CAI was 0.7, AHI was 5.7 events / hr and RDI was 19.6 events/hr. 
 
Oximetry:  Mean awake oxyhemoglobin saturation was 95.3%.  The mean sleep oxyhemoglobin saturation was 94.3% with an oxygen nadir 90.0%.  
 
Total Apneas                    = 4  with Avg. Duration = 11.7 sec
Central Apneas                 = 3  with Avg. Duration = 12.2 sec
Obstructive Apneas          = 1  with Avg. Duration = 10.0 sec (AHI=5.7/hr)
Hypopneas                       = 19 with Avg. Duration = 34.8 sec
Apnea + Hypopneas         = 23 with Avg. Duration = 30.8 sec
RERE                                = 56 with Avg. Duration = 118  sec
Respiratory Total               = 79 with Avg. Duration = 92.5 sec (RDI=19.6/hr)
RERSCA                             = 49 with Avg. Duration = 106  sec
Research Respiratory Total = 128 with Avg. Duration = 198 sec
 
Respiratory Effort Related Event (RERE)
Respiratory Effort Related Sub-Cortical Arousal (RERSCA)
 
Respiratory Disturbance Index (RDI) = 19.6/hr
Sleep Leg Movement = 3/hr
Total Sleep Event Index = 21.6/hr
Respiratory Sub-Cortical Arousals = 12.1/hr
Research RDI = 31.7/hr
 
My Sleep Study Report: https://youtu.be/cA_Rcq3DXb4 (remove the space after https) Fixed it for ya - Moderator
 
Questions

1. I understand that CPAP, APAP, and even Bilevel machines can be used to treat the various forms of disordered breathing – CSA, OSA, and RERAs. However, the newer ASV units seem to come closest to mimicking a person’s natural breathing while providing the minimum required support. Intuitively, along with the fact that the brain’s lymph system for clearing toxins operates on 7cm of water, it would seem to me that ASV should be the PAP therapy of first choice and not the last - barring financial constraints. It just seems to me that the generally accepted approach of first trying CPAP, then APAP, then Bilevel, and only using ASV when a whole host of conditions is met, is basically an insurance industry driven model. That’s all well and good for the insurance industry but I often hear doctors and experts talk like some of the less adaptive PAP machines are the best possible choice medically. I wonder if this is really true and if I’m missing something or whether these folks have inadvertently been drawn into the insurance industry’s profit making model. Is there a post where machine selection is discussed based upon the types of disordered breathing? I’ve found bits and pieces but no comprehensive discussion.
   
2. I have a lot of RERA events with next to no OSA or CSA. From what I’ve been able to glean from this very helpful forum, adaptive PAP therapy is a better option for me. My thinking is to purchase an ASV machine out-of-pocket as the concept of varying tidal volume on a breath-to-breath basis along with being able to vary EPAP makes ASV look like it comes much closer to following my body’s natural breathing than even Bilevel. Are these the two main differences between Bilevel and ASV? Am I making the right choice based upon my sleep data?
   
3. One concern I have is that I read that ASV is harder than Bilevel for some to get used to. On the other hand, I have tried both Bilevel and ASV and found ASV to be much more comfortable. Sleep expert, Dr. Krakow, has written that without exception folks that have used other PAP therapy prior found ASV to be way better when put on these machines. Why do some have issues with ASV?
   
4. It’s my understanding that the ResMed AirCurve 10 ASV is mostly automated while the DreamStation AutoSV has more settings like Breaths-Per-Minute (BPM). Is it possible with either of these machines to turn off the feature wherein the machine forces a breath when a person stops breathing? I know this probably sounds like a crazy person’s question in a PAP forum but I have next to zero central and obstructive apneas that last only slightly more than 10 seconds so being able to turn off this feature may make sense for me – I read it’s a hassle when you’re awake and this function kicks in. Do Bilevel machines all kick in when a person stops breathing like ASV?
   

 
I know I’ve just asked a ton of questions. I apologize for that. I just don’t know where else to go for answers to these questions. I’ve been through hell and I want to give this old, beat up body the best possible chance. For what it’s worth, I have donated to the forum.

Thanks you all.

[tmoody]

It’s my understanding that the ResMed AirCurve 10 ASV is mostly automated while the DreamStation AutoSV has more settings like Breaths-Per-Minute (BPM). Is it possible with either of these machines to turn off the feature wherein the machine forces a breath when a person stops breathing? I know this probably sounds like a crazy person’s question in a PAP forum but I have next to zero central and obstructive apneas that last only slightly more than 10 seconds so being able to turn off this feature may make sense for me – I read it’s a hassle when you’re awake and this function kicks in.

I'm going to take a shot at just this question. I've been on ASV for about a year and a half; CPAP for nine years before that. I had a brief stint with BiPAP that didn't work out so well, although I now wonder if playing with settings might have helped.
ANYWAY...Yes, it can be a hassle when the ASV algorithm kicks in if you're still awake, and that's one of the reasons why some people have trouble adjusting to ASV. In addition, if you're in a light sleep, the ASV action can sometimes actually wake you up.
The BPM setting is still considered part of the ASV repertoire. The difference between manually set BPM and "auto" is that the "auto" setting is constantly averaging the timing of your most recent breaths and attempting to keep it steady. The BPM setting is a fixed minimum that it tries to keep you from going below. I've recently experimented with switching from auto to BPM, and so far the results have been good. That is, my AHI is down and I'm feeling a bit more rested. But that depends on your particular situation, particularly the prevalence of centrals and why they're happening. The lower the BPM, the closer the machine is to doing what a BiPAP does. If I were to set BPM=0 I'd be effectively turning the machine into a BiPAP, because at BPM=0 there wouldn't be any machine-triggered breaths.
But if you have few or no centrals, you don't need either the auto or BPM capabilities so it's not clear why you'd want an ASV in the first place. ASV is really all about treating centrals that don't respond to other pressure settings.

This, at least, is my current understanding of things. I'm not an authority. Others will correct my mistakes, I hope.

[SarcasticDave94]

As one that has had to get the ASV machine after failing both CPAP and BiPAP, for ME ASV has made dealing with apnea therapy much easier. BUT this is the ONLY solution via xPap for my situation. Is going through the required insurance hoops fun? No, but I understand why they do this. IMO it helps keep costs down, at least to a finite degree. Will an ASV work for everyone? IMO yes. Is it NEEDED? No, it can't be justified to issue everyone an ASV machine.

As for some having trouble getting used to the ASV, I'm not on that list. In fact, I'm better able to meet compliance and personal daily use because of my ASV friend.

Oh yeah, welcome to Apnea Board.

Dave B.

[Greggory]

...when the ASV algorithm kicks in if you're still awake, and that's one of the reasons why some people have trouble adjusting to ASV. In addition, if you're in a light sleep, the ASV action can sometimes actually wake you up...

... If I were to set BPM=0 I'd be effectively turning the machine into a BiPAP, because at BPM=0 there wouldn't be any machine-triggered breaths...

...if you have few or no centrals, you don't need either the auto or BPM capabilities so it's not clear why you'd want an ASV in the first place. ASV is really all about treating centrals that don't respond to other pressure settings...

Thanks tmoody.

It's reassuring to hear that the reason some have trouble with ASV is due to the machine maintaining a minimum breath rate. I didn't really have an issue with this so I'm more comfortable now with choosing ASV.

I'm also glad you were able to confirm that when the Backup Breath Rate or Breaths Per Minute (BPM) is set to zero, you've essentially reduces ASV to a Bilevel machine. This what I'd heard but was unsure about. I think ASV also regulates based upon the volume of air being taken in while Bilevel doesn't. Do you know if this is the case or do some of the more advanced Bilevel machines also regulate based upon breath volume?

I'm of the conviction that the closer a PAP machine comes to following my natural breath while providing the support needed, the less likelihood of issues in the future. For example, I've heard that over time folks on less sophisticated PAP machines (especially CPAP) tend to develop more central apneas over time. Don't know; maybe this is wrong? There is also the issue of inflating my head at pressures in excess of those required for the brain's natural lymph system to work. I worry about the impact of this long term. And finally, I'm totally into getting the most comfortable machine. Per what I've heard from others and my own experience, ASV tends to be well above the rest.

Really, your input is very useful.

[Greggory]

...Will an ASV work for everyone? IMO yes. Is it NEEDED? No, it can't be justified to issue everyone an ASV machine...

SarcasticDave94,

Thanks for your input and support. It's useful to know that you found ASV helpful and that you think it could work for everyone.

While I agree that the current dog-eat-dog mentality that humankind currently operates under results in insurance companies forcing cheaper PAP machines that are less comfortable and more problematic long-term on its clientele, my hope is that someday in the near future this changes. Given the advances in technology, I firmly believe that it's now possible to more than meet the basic needs of everyone on the planet. If we choose, we don't have to live under a competitive paradigm that forces each of us to excel at the expense of the planet and our neighbors anymore. Maybe as little as 100 years ago this was true, but not today.

I know there are all sorts of caveats but my main point is that once the human race begins to operate out of a place of abundance and connectivity instead of the current scarcity and separatism model, I think everyone that needs critical, potentially life changing, and very inexpensive medical support like PAP therapy, will easily be able to use ASV. But then I've digressed wildly from the topic at hand.

Thanks again for your input.

[SarcasticDave94]

You're welcome and I understand and appreciate where you're coming from. To a great day and weekend ahead:

[jerrydaw]

For me, ASV therapy was no problem getting used to.  It felt completely natural from the start.  The biggest problem I have had with ASV is the higher pressures and mask leakage.  I have found it hard to find a  mask that can truly take the higher pressures associated with the ASV machine.  I am using the ResMed F20 AirSense. That seems to work better than any I have tried.  

And yes, you do have to jump through hoops to get Medicare to pay for the machine.  Like most, I had to prove CAPA and BiPAP did not work for my condition of central apneas.  Even had to take an additional Sleep Test using an ASV machine to prove it worked for me. Considering the expense of the ASV machine, I can understand Medicare and other insurance companies not wanting to waste money on an expensive device that was not going to work for that individual. 

If you have centrals, ASV is the only therapy that will treat the condition.  Unfortunately, about half of my total events were centrals.

My advice is to be persistent and get the therapy that will properly treat your condition.  Sometimes, you even have to push your doctor in the proper direction.  My doctor  was content to let me wallow along with a BiPAP machine, until I pushed for the ASV.

[tmoody]

I'm of the conviction that the closer a PAP machine comes to following my natural breath while providing the support needed, the less likelihood of issues in the future. For example, I've heard that over time folks on less sophisticated PAP machines (especially CPAP) tend to develop more central apneas over time. Don't know; maybe this is wrong?

Yes, I've heard this too, and I may be an illustrative case. I was diagnosed with severe OSA in 2006 (AHI=42) and given a straight CPAP set at a constant pressure of 11. I used the thing (Resmed S8, I think) with no issues for nine years. I never went back to the sleep doc either. I had no idea that these machines wear out, but by 2015 I knew it was getting noisy, so I looked into getting a new one. I thought I could just buy one. In all that time I never bothered looking up information about settings and hadn't visited forums like this one. I soon learned that I'd need to get a new prescription.

I went to the doc (who had to dig my record out of storage) and he prescribed a DreamStation autoBiPAP without another sleep study, on the assumption that it would automatically find the right settings. This machine, unlike my previous one, was data capable, so I started monitoring the readouts. I don't remember what the settings were, but my AHI was not well controlled, fluctuating between 5 and 15, with a fair number of centrals and a good deal of periodic breathing. I had no idea what this meant and a bit of googling did nothing to reassure me.

I don't know whether I might have gotten better results with the DreamStation by adjusting the settings. I suspect I might have. I also don't know if the appearance of centrals was a consequence of nine years of CPAP but I guess it's possible. When I checked back in with the sleep doctor in something of a panic over this, he was gone, due to illness, and a different doctor simply ordered another sleep study, expressing no interest in fiddling with the DreamStation settings. The new sleep study showed "mixed" apnea and I was switched to a Phillips System One ASV. My initial results with this machine were fair, but eventually I found my way here and was able to get things dialed in much better.

I actually liked the DreamStation; it felt very comfortable to use. But the centrals and PB were a definite concern. In contrast, the ASV "auto" mode felt intrusive, but it eventually worked better in terms of measurable results, once I got the settings sorted out. Some people report that the AirCurve Auto has a smoother algorithm than the Phillips System One ASV. Not having tried it, I can't say, but it's something to consider if you're thinking of going the ASV route.

[SarcasticDave94]

For me, ASV therapy was no problem getting used to.  It felt completely natural from the start.  The biggest problem I have had with ASV is the higher pressures and mask leakage.  I have found it hard to find a  mask that can truly take the higher pressures associated with the ASV machine.  I am using the ResMed F20 AirSense. That seems to work better than any I have tried.  

And yes, you do have to jump through hoops to get Medicare to pay for the machine.  Like most, I had to prove CAPA and BiPAP did not work for my condition of central apneas.  Even had to take an additional Sleep Test using an ASV machine to prove it worked for me. Considering the expense of the ASV machine, I can understand Medicare and other insurance companies not wanting to waste money on an expensive device that was not going to work for that individual. 

If you have centrals, ASV is the only therapy that will treat the condition.  Unfortunately, about half of my total events were centrals.

My advice is to be persistent and get the therapy that will properly treat your condition.  Sometimes, you even have to push your doctor in the proper direction.  My doctor  was content to let me wallow along with a BiPAP machine, until I pushed for the ASV.

jerrydaw,

I happen to be in the same boat. The ASV tested my abilities to adjust the mask until I found the best adjustment settings. I'm using the AirFit F20; secondary option is AirTouch F20. And I had to start the ASV path by getting an Urgent Need appointment at the pulmonary doctors office as BiPAP was causing very high CA. The light finally was turned on when I pointed the CA count on that BiPAP PSG/titration.

Dave

[Greggory]

Thanks tmoody. It’s useful to hear your experience with CPAP and that you found ASV to be very comfortable.

For other Newbies reading this discussion, here’s what I’ve learned to date.

When it comes to treating disordered breathing due to sleep obstructions with PAP therapy, the basic approach is to pressurize the entire oral and chest cavity with enough air so as to hold open that portion of the airway that otherwise collapses. In essence, PAP machines blow the airway up like a balloon. Personally, it’s hard for me to imagine there aren’t long-term health consequences to this for a certain percentage. The fact that I’ve read reports that some have dramatic increases in central apneas with CPAP and even Bilevel machines suggests that the body isn’t entirely happy with the process; the human body is exquisitely interconnected and complex. Granted, PAP therapy is one of the better solutions when sleep disordered breathing is present, but I really do wonder about the use of less adaptive PAP machines.

When it comes to treating disordered breathing due to an obstruction that completely closes off the airway as in Obstructive Sleep Apnea (OSA) or due to a restriction as in Respiratory Effort Related Arousals (RERA), the basic approach is to blow up the airway using PAP therapy. The inexpensive approach to this that the insurance industry promotes is to apply one constant and relatively high pressure (ie CPCP). Generally, only if a person has problems like increased central apneas are more adaptive machines made available that better mimic naturally breathing. In the case of BiPAP, the machine has the ability to vary the inspiratory pressure in rhythm with the body while also keeping pressures high enough to keep the airway open. Note: Some folks seem to make a distinction between word usage when it comes to “obstructive” versus “restrictive”.

From what I can glean, there are lots of other features like being able to change the Breaths Per Minute (BPM), Rise Time (RT), and Inspiration Time (IT) on each of the main types of machines that often allow each basic machine type to come close to operating like its more adaptive successor. This isn’t totally clear to me yet as there is a lot of jargon to learn and machine designations are utterly confusing. Still, it seems that a good quality machine of whatever type tends to have quite a few settings and the ability to capture data that can be read by the user in order to adjust their particular machine and bring AHI scores way down. Given the fact that conventional medicine essentially left me for dead, I’m totally into being able to adjust my machine and take control of my own health.

When it comes to ASV, the defining difference seems to be that the machine also has the ability to vary pressures based upon the tidal volume (total amount of air delivered) in concert with what the body is naturally doing. When I tried BiPAP, there was a more forced element to it; it felt like I was being expanded too much with each breath. Within a few breaths on ASV, the fact that the machine regulates pressures based upon the average volume of air a person is taking in was really apparent and felt way better.

I’ve read that the downside of ASV is that it will really crank up Pressure Support (the difference between inhalation and exhalation pressures) very rapidly when it senses an excessive drop in tidal volume (TV). Not surprising, this can wake some folks up. Given that I mostly suffer from RERA types of disordered breathing (sucking air through a straw all night), I don’t tend to have the waxing and waning of breath volume that people with Cheyne-Stokes and other breathing disorders have. As such, I don’t think ASV was altering Pressure Support (PS) much as I slept; I’m a very light sleeper and think I would have woken up.

If rapid changes in Pressure Support (PS) wakes a person up too much and they don’t have some complex mix of sleep apnea that demands the use of ASV, BiPAP seems like the way to go. Like ASV, BiPAP has the ability to address obstructed and restricted breathing along with central apneas (when the brain stops sending the signal to breath). It does this by being able to vary the inhalation pressure over a fairly wide range while having fixed exhalation pressure (I don’t think BiPAP has a variable inhalation pressure like ASV).  BiPAP makes these pressure adjustments more slowly but nonetheless tries to induce breathing during central apneas by increasing the difference between the inhalation pressure (IP) and exhalation pressure (EP) – the Pressure Support (PS). CPAP and its variants can not treat central apneas.

In terms of the better ResMed ASV or Respironics (Dreamstation) ASV machines, it appears that the Dreamstation has a lot more settings that a person can change; ResMed is mostly auto adjusting. With this in mind, the other main complaint with ASV (besides the rapid PS changes) is that it will force a breath while you’re still awake and naturally stop breathing because you’re maybe focusing on something. Given that central apneas really aren’t my issue, I’m seriously thinking about getting the Dreamstation where I can turn the Backup Breath Rate way down and thereby eliminate the forced breath issue.

Well, I thought I’d write down what I’ve been able to pick up so far in case it helps some other Newbie. Granted, everyone is different and I’m looking at PAP therapy from a particular perspective but it’s at least one point of reference that may be helpful to others. Note: If I got anything wrong, would someone please correct me?