ASV: Hypopnea Index Remains High

StillAnotherGuess wrote:

BrianinTN wrote:but what's gained by lowering the max pressure to 25? From the graphs, it never gets close to that high as it is.

Your device will run more efficiently and provide longer device life at lower Max Pressure. You could happily set Max Pressure 20. People on this board love to run there devices at the highest possible Max Pressure. It tears these machines up, as has been demonstrated many times with run-away pressures and burnt-out machines, by many forum users. Running your device at Max Pressure 30 is almost as dumb as the person who set your device parameters to run on 'Auto'.

If the device never spends any time at the higher pressures, there cannot be any wear. This is faulty reasoning. Given the excursions he is experiencing I would leave the limits large.

PS

Guest wrote:

BrianinTN wrote: My settings are pretty standard: Min EPAP 4, Max EPAP 15, Min PS 0, Max PS 15, Max Pressure 30, Backup rate auto, Flex setting 2.

My guess is running the autoSV on straight auto mode, as indicated by your current settings, isn't an effective modality to address your hypopnea. You could trial Min PS 3, tonight. You may also entertain Max Pressure 25.

I like this idea as well. I find it comfortable to have that 3psi difference that makes it easier to take a breath. Its easier to fall asleep. I wonder if that flex setting has to do with making things more difficult. Maybe somebody will chime in as to what that setting does. My backup rate was first set at auto and I was getting a lot of large excursions in pressure. I did some counting while trying to sleep and decided my natural backup rate was around 8pbm. When we set it to that instead of auto, the number of sudden jolts to high pressure decreased and it became much easier to sleep. I don't know what the minimum backup rate is for "auto" but it made a big difference for me to pick an actual number. Be sure if you do set a backup rate, to pick a number low enough. My DME first picked 15 and it was near impossible to sleep because it kept punching up the pressure in sudden bursts just as I was starting to nod off.

Looks like your mask is sealing pretty well. Nobody has asked yet, but are you sleeping pretty well with the unit being fairly unobtrusive or does it feel like you are fighting with the pressures?

My first few nights on my unit show that I was not breathing on my own for minutes at a time but I was oblivious because I was exhausted. As I started getting more rested (around 4 hours a night), it became harder to sleep because I was rested enough to be awakened by the pressure excursions.

So, things to consider with your DME or doctor
set a min PS
set a BPM backup rate
find out what flex does

Good luck, one of these days I will figure out a way to host and put some of my pics up too.

I have a call into my doc, although he won't be back into the office on Monday....

avi123 wrote:I have used the Fisher & Paykel #432 full face, as you do, for a few weeks and had high leak rates with it like you (above 30 L/min). I think that the solid foam under the Silicone cushion caused it. So I changed to full face #431 (without the foam), in medium size, and it works much better. The leak dropped to below 10 L/min.

I've tried a bunch of FFMs and hybrids, including the ComfortGel Full, the Mirage Liberty, and the Mirage Quattro. None of those have felt comfortable to me. The foam on the 432 is actually one of the things that I liked -- but I get your point. If there's no foam on the 431, what prevents it from being uncomfortable?

Mr Bill wrote:My backup rate was first set at auto and I was getting a lot of large excursions in pressure.

On my old BiPAP S/T, it had a backup rate of 16. (As you can see, my sleeping BPM is around 18, so the setting was -- technically -- correct.) However, I think I naturally breathe a lot more slowly while *going* to sleep, so this made getting to sleep extremely difficult.

Mr Bill wrote:are you sleeping pretty well with the unit being fairly unobtrusive or does it feel like you are fighting with the pressures?

I wouldn't say I'm sleeping very well, but the air pressure is a LOT less disruptive than it was on CPAP (13 cm) and BiPAP (20/16). I still wake up a few times a night, but I was doing that anyway. My bigger problem is that I generally feel more tired the next day than I was without a machine. It's not nearly as bad as things were on the BiPAP, where I was non-functional and a hazard to the road, but I'm sleeping a lot more and taking more naps and just don't feel refreshed.

Back on my CPAP, FLEX was explained to me as a relief against exhaling pressure. I think that's why the fellow several posts up was suggesting that it be off -- because my IPAP was so low to begin with. However, the settings I currently have been using are exactly as were dictated in my ASV titration study (you can see those results here: viewtopic.php?f=1&t=61719&p=587658#p587658). I aced that with flying colors, and actually felt oddly refreshed the next morning (although I was tired the rest of the day).

So yeah, I don't know what's going on. I'll ask the doc on Monday and hopefully he'll give me some pointers, although I don't know how much experience he has with ASVs in general.

I had no idea how tired I was till I started getting sleep. My first 3-4 months I was averaging 4-4.5 hours a night. I felt better but I remarked to my friends that now that I was getting some sleep I actually was starting to feel lack of sleep! I'm up to a little over 6 hours a night average. I just can't seem to stay asleep most nights much longer than that. But the nights I have slept 8-9 hours; Oh man! Its wonderful, my mind is so clear and sharp!

Back on my CPAP, FLEX was explained to me as a relief against exhaling pressure.

I think having the PS min set gives you the equivalent of that sort of FLEX. That's why I am wondering what it is on our units.

Yeah, my typical number on the ASV is also around 18 BPM. Walking around or first falling asleep, is a different matter. I wonder why its so fast?

del

You're correct. No one has diagnosed any other underlying condition. An examination of my tonsils showed them to be huge, and I'm not tiny (220 lb), and my neck circumference is on the larger side, all of which contribute to the OSA. As for my developing centrals while on CPAP, my doc had told me that it's just something that happens with people and they don't know why.

As for the machines -- the CPAP induced centrals, so they put me on a BiPAP S/T. My AHI on that at home was around 35, so I went in for an ASV titration. We never got to insurance problems because my DME agreed to do a swap of the BiPAP for the ASV without involving insurance.

del

I did read it. However, I'm not convinced that I have another underlying condition that's causing my CompSAS. There's nothing in any of my other tests to suggest any of the various disorders, CS breathing patterns, etc. As the first paragraph in your link so aptly put it, "Primary central sleep apnea is a rare condition, the etiology of which is not entirely understood." An important distinction here is that I do *not* have central sleep apnea -- but rather complex sleep apnea. My understanding is that my original PSG, without CPAP, showed only obstructive events.

My doc is board certified in sleep medicine, although pulmonary is his primary specialty. I'm talking to him again next week to see what he says. ASVs are relatively new to the US anyway, so I don't really hold it against him if he hasn't had experience with that many CompSAS patients.

Oh, and as for the first paragraph -- no substance abuse problems here. I have never once taken an illegal narcotic, I don't drink often, etc. The only thing that could potentially be a problem would be taking the clonazepam -- but I do this only to help me sleep with the ASV and don't take it otherwise, so the logic doesn't work out there. Ambien actually has been shown to *help* with centrals in sleep onset, and again, I only take it these days when trying to use a breathing apparatus, so that ought not be an issue either. In a nutshell: I'm clean as a whistle.

Your Rx seem to be based on the assumption the auto mode is good for you.
Here's a link to Respironics' FAQ about ASV: http://bipapautosv.respironics.com/faq.aspx

Note these FAQ's:

Does the BiPAP autoSV operate like an Auto CPAP or Auto Bi-level device for treating obstructive events?
No – The device does not have an auto-titrating algorithm to alleviate obstructive events. The innovative algorithm was designed to treat complex apnea and periodic breathing. The obstructive component of SDB is treated utilizing a clinician adjustable CPAP or BiPAP pressure level.

Is it necessary to titrate these patients?
Yes. To treat the complexity of this patients as well as establish a baseline CPAP or BiPAP pressure for OSA, an in lab titration is necessary.

(Added emphasis mine, in both answers)
Granted, this is not the newer (PR) machine - and I don't know if the new one is different (I wouldn't think so) - but I do know that leaving any self adjusting machine to range from super low to super high is not good for therapy purposes, though it may be excellent for titration. And it is probably worse for people with CompSAS.

Your machine is not set at whatever baseline pressure they discovered was good for you when the titration ended.

ozij wrote:Your Rx seem to be based on the assumption the auto mode is good for you.
Here's a link to Respironics' FAQ about ASV: http://bipapautosv.respironics.com/faq.aspx

Note these FAQ's:

I do know that leaving any self adjusting machine to range from super low to super high is not good for therapy purposes, though it may be excellent for titration. And it is probably worse for people with CompSAS.

Your machine is not set at whatever baseline pressure they discovered was good for you when the titration ended.

I don't mean any disrespect but this does not make any sense to me.
I have mixed apnea with Cheyne-Stokes. The OSA component is well controlled at a pressure of 11. The CSA is totally separate from the OSA - it is not a result of the machine. I need a wide range of pressures to control the CSA and the Cheyne-Stokes because my breathing is so disordered. I think it is a good idea for people to take charge of their own treatment but I think it is a bad idea for people to disregard the evidence of the PSG (or in my case, multiple PSGs).

Some people have predominately centrals in their initial titration that get worse when CPAP, or BIPAP, or oxygen, or a combination of all three are tried. That would be my own case. I am relatively young and I don't think I have any heart problems unless complex sleep apnea is causing them. 4 years ago, at 50 I did a fully wired treadmill test and CT scan and passed with flying colors. The sleep apnea may have been present but it did not get bad till the following year, 2008.

Other people have predominately obstructive apnea, but on treatment, develop central events so severe, that an ASV is required to fix the problem. I think that about describes BrianinTN from what I've read here. Both cases are complex sleep apnea but may have different underlying causes. My prescribing sleep doctor thinks many people with CSA may have it because of altitude.

máirtín wrote:

ozij wrote:Your Rx seem to be based on the assumption the auto mode is good for you.
Here's a link to Respironics' FAQ about ASV: http://bipapautosv.respironics.com/faq.aspx

Note these FAQ's:

I do know that leaving any self adjusting machine to range from super low to super high is not good for therapy purposes, though it may be excellent for titration. And it is probably worse for people with CompSAS.

Your machine is not set at whatever baseline pressure they discovered was good for you when the titration ended.

I don't mean any disrespect but this does not make any sense to me.
I have mixed apnea with Cheyne-Stokes. The OSA component is well controlled at a pressure of 11.

Not sure what makes no sense to you - is your machine set to roam from 4 and upwards in response to obstructive apneas? If it is, what do you mean by "OSA well controlled a a pressure or 11" ?

The CSA is totally separate from the OSA - it is not a result of the machine.

True for Cheyne-Stokes.

I need a wide range of pressures to control the CSA and the Cheyne-Stokes because my breathing is so disordered. I think it is a good idea for people to take charge of their own treatment but I think it is a bad idea for people to disregard the evidence of the PSG (or in my case, multiple PSGs).

That's what a properly set ASV does.


Correction of my post above: The new ASV does titrate the obstructive component. However auto function for titrating OSA is sleep disruptive for some people.

There seems to be some confusion here. First, the entire purpose of being on an ASV is to have some auto adjustment. The "A" stands for "adaptive," after all. Yes, for some people, the therapy is more effective if you set limits on just what decisions the machine can and cannot make -- which was really my ultimate purpose in posting this thread (to get some input on what tweaks might be most effective, rather than going through many more weeks of trial and error like I did on my BiPAP S/T).

For CompSAS, you definitely need that adjustment. As máirtín pointed out, the obstructive and central components are different. In my own case, I know that I have positional obstructive apnea (much worse on my back, of course), which means that a single pressure was never quite right for me anyway. I also know that CPAP and BiPAP S/T therapies both triggered centrals and hypopneas, which is how I've arrived at the ASV. Again, I have no known neurological conditions, CSB, or any of the other common factors contributing to central apnea.

Not letting the ASV adjust pressures pretty much would defeat the point of having it. And an ASV is the gold standard for treatment of CompSAS. My problem is that the ASV hasn't quite figured out how to get it quite right left to its own devices. There are things that can be tinkered with, including minimum and maximum pressures, minimum pressure support (IPAP-EPAP), the flex setting, and the backup breathing rate.

ozij, the current settings for my machine are precisely those from the end of my titration. They left it basically in the same mode it comes out-of-the-box, and the clinician did not have to adjust a single setting throughout the entire night. He told me this, and I saw the sleep study which showed only a couple hypopneas throughout the night. My problem is simply that my home results, despite matching those in-lab titration settings, are not coming out as good.

-SWS had helped JIMCHI in another thread by dictating a matrix of possible settings to improve his luck with the ASV. Ultimately, that's what I'm trying to get at here as well -- where should I go first?

BrianinTN wrote:

Mr Bill wrote:are you sleeping pretty well with the unit being fairly unobtrusive or does it feel like you are fighting with the pressures?

I wouldn't say I'm sleeping very well, but the air pressure is a LOT less disruptive than it was on CPAP (13 cm) and BiPAP (20/16). I still wake up a few times a night, but I was doing that anyway. My bigger problem is that I generally feel more tired the next day than I was without a machine. It's not nearly as bad as things were on the BiPAP, where I was non-functional and a hazard to the road, but I'm sleeping a lot more and taking more naps and just don't feel refreshed.

Back on my CPAP, FLEX was explained to me as a relief against exhaling pressure. I think that's why the fellow several posts up was suggesting that it be off -- because my IPAP was so low to begin with. However, the settings I currently have been using are exactly as were dictated in my ASV titration study (you can see those results here: viewtopic.php?f=1&t=61719&p=587658#p587658). I aced that with flying colors, and actually felt oddly refreshed the next morning (although I was tired the rest of the day).

So yeah, I don't know what's going on. I'll ask the doc on Monday and hopefully he'll give me some pointers, although I don't know how much experience he has with ASVs in general.

So... I will reiterate what I said before...

Mr Bill wrote:I had no idea how tired I was till I started getting sleep. My first 3-4 months I was averaging 4-4.5 hours a night. I felt better but I remarked to my friends that now that I was getting some sleep I actually was starting to feel lack of sleep! I'm up to a little over 6 hours a night average. I just can't seem to stay asleep most nights much longer than that. But the nights I have slept 8-9 hours; Oh man! Its wonderful, my mind is so clear and sharp!

It may be a while before you really start getting rested because your body needs time to adjust to the new availability of oxygen. My DME told me six months. Part of the problem is I am so used to little sleep that even getting a little makes me feel like staying up till 2:30 am like right now, instead of sleeping, which I really am right not going to go do.

Oh one more thing, maybe this will work for you also. I find I get more pressure excursions and higher AHI on my sides than on my back. I think for me its that breathing effort seems harder on my side and on my back seems easiest as I am drifting off to sleep. Maybe that is my tendency for centrals, I'm not sure. So, I just sleep on my back and let the ASV take care of it all. Maybe you should try it. Goodnight!

BrianinTN wrote:There seems to be some confusion here.

Indeed.
ASV stands for Auto Servo Ventilation.

Auto Servo Ventilation is not APAP therapy for OSA.

You should know the difference between these two. And ASV machine can be run as a CPAP with ASV.

Deleted