No Answers Yet For Problems With ASV

JohnBFisher
My sleep doctor has opined that complex sleep apnea is caused by altitude (I live at 4600 feet elevation) and SWS posted this link about that relationship...
http://chestjournal.chestpubs.org/conte ... /1744.full
in this thread...
BiPAP ST User Needs Help with Centrals/Hypopneas
viewtopic.php?f=1&t=61719&p=579173#p579173

I still wonder if there is an underlying cardiac problem that might be causing this.
Bill

Mr Bill wrote:... I still wonder if there is an underlying cardiac problem that might be causing this. ...

If test ruled out cardiac issues, then I would tend to believe the doctor. Altitude is a known contributor to central sleep apnea.

This is in follow up to one of my earlier posts in this thread. I am confused about the Respironics Rep's advice to switch me from my BiPAP ASV to a straight BiPAP, set at 5/15.

Copied from the earlier post, with a little bit of change: I don't know what would be different with a regular BiPAP. Why it would work better. I also asked the RT why going to a regular BiPAP would makes sense, considering that during the titration study, I started with a regular BiPAP and was switched to the ASV.

She said during the initial study, the number of central events was so low that they don't really warrant treatment. But, my understanding is that during REM sleep, the number of central events wasn't so low. My read on the report is that during REM sleep, my central event index was 14.3. The total index on central events is only low because I wasn't in REM sleep very long. Does anyone have any thoughts on this?

Also, in the earlier post, I had asked if it is possible to set the ASV to function like a straight BiPAP.

I guess what I am really asking with all that is: If I could set my ASV to perform like a regular BiPAP, would it make sense to try that in order to get my residual hypopneas and/ or low patient triggered breath percent looking better?

The update on my information is that my AHI's so far this week have ranged from 4.0 to 8.0. Percent Patient Triggered Breaths has ranged from 40.1 to 64.0. And I am not feeling as chipper and perky as I would like.

Deborah

Edit to clarify reference to Respironics Rep

Mr Bill wrote:My sleep doctor has opined that complex sleep apnea is caused by altitude (I live at 4600 feet elevation)

I am at 4100, but I don't think that's high enough to cause central apneas. People are usually a little out of breath when they first move here, but that's the only problem I've heard of here.

Mr Bill wrote:I still wonder if there is an underlying cardiac problem that might be causing this.

You had all the standard cardio tests done, didn't you, and they turned out okay?

I just had a cardiac echo done last week. One of the medications I took several years ago has a potential side effect of cardiac problems, some of which can show up years down the road. So, every couple years now, I get to have an echo done.

Deborah

Paper_Nanny wrote:The update on my information is that my AHI's so far this week have ranged from 4.0 to 8.0. Percent Patient Triggered Breaths has ranged from 40.1 to 64.0. And I am not feeling as chipper and perky as I would like.

And here is the big lump of graphs from the past week...













Many times I did edit this post in an attempt to make the graphs of Decent and Proper Size so that they could be Read With Ease. I hope that I did succeed.

This is a graph I compiled yesterday that was of interest to me. It is the trend data from my ASV showing the graph of percent patient triggered breaths along with the inverse of the graphs of hypopnea index and total ahi. It is very clear that as self initiated breaths go down, the ahi and hi go up. Or that as the ahi and hi go up, the patient triggered breaths go down. Which is cause and which is effect? And is it correct that it is the breaths I am initiating during these times that are the hypopneas and not the ones the machine is initiating?

What can I do to correct the situation? I already decreased my EPAP min from 8 to 6 and that lowered the AHI quite a bit. But how can I lower it even more?




edit to correct typographical error

I wonder how well patient initiated breaths would correlate with sleeping on your back?

Mr Bill wrote:I wonder how well patient initiated breaths would correlate with sleeping on your back?

As far as I can tell, I don't sleep on my back much. Husband has only seen me sleep that way a few times in the mornings after he has gotten up for work. Before he gets up, I'm not sure there is room for me to sleep on my back. We have a regular double bed and it's him, me, and two large dogs sleeping together. I usually sleep on my right side and I think being sandwiched between Dog and Husband keeps me from rolling over.

I know I fall asleep on my side and any time I have gottn up in the middle of the night, I wake up that way. Husband hasn't seen me on my back when he wakes up during the night.

The other night, though, Husband did say he had heard the flap on my mask making a werid flapping noise. He said it sounded like snoring through the mask. I wasn't on my back, but did have my head flopped over funny. He said the noise went away once he turned my head back over. I checked the data in the morning and there were hypopneas flagged and patient triggered breaths were low.

So, maybe it correlates not so much with being on my back as with my head being turned funny? But how would I know if I were doing that? Maybe I could sew a tennis ball to the back of my head gear to keep my head from tipping and see if it made a difference in my patient triggered breaths?

Deborah

Well, then, whatever position you start sleeping in each night seems to give you the most self initiated breaths. It looks like you go 2 to 5 hours and then you initiate far less. Maybe its a sleep stage but maybe its sleep position. For myself, if I sleep without my ASV my pulse oximetry repeats like clockwork. I go for an hour at good saturation followed by an hour with regular deep oxygen saturations and so on, repeating all night. When using the ASV, I see the same pattern but fixed with respect to oxygen saturation. The oxygen saturation is good but every hour for about an hour it gets choppy in O2 saturation (staying above 90%) and to a lesser extent in heart rate.

According to the sleep tech my oxygen saturation pattern without an ASV looks like one that is typical for REM specific OSA. Except it seems to be REM specific CSA. I guess CSA is supposed to get better during REM stage for most people but that is where mine is worst. The portions of the night when oxygenation is good, I was actually 'awake' according to the brain scans.

Mr Bill wrote:It looks like you go 2 to 5 hours and then you initiate far less. Maybe its a sleep stage but maybe its sleep position.

I was thinking it was sleep stage, but maybe not. Maybe it is position. I wonder how I can figure out what position I am sleeping in.

Mr Bill wrote:According to the sleep tech my oxygen saturation pattern without an ASV looks like one that is typical for REM specific OSA. Except it seems to be REM specific CSA. I guess CSA is supposed to get better during REM stage for most people but that is where mine is worst.

If I am reading my report correctly, that is exactly what mine looks like. REM specific CSA.

In the graph I posted of the patient triggered breaths and the inverse of the apneas, does it look at all cyclic to anyone? Like the rising and falling pattern repeats across time? One of the other things I am wondering about is whether the apnea and PTB's are on their own special time cycle.

Deborah

Going back to a suggestion made by BrianinTN, I am going to change my pressure support to three and see what happens. Here's hoping for a good night of sleep,
Deborah

Paper_Nanny wrote:The update on my information is that my AHI's so far this week have ranged from 4.0 to 8.0.

Those numbers aren't awful, but (a) they're actually comparable to your diagnostic study, suggesting we aren't getting much improvement, and (b) the fact that you aren't feeling "chipper and perky" as you put it is most concerning.

Paper_Nanny wrote:during REM sleep, the number of central events wasn't so low. My read on the report is that during REM sleep, my central event index was 14.3. The total index on central events is only low because I wasn't in REM sleep very long. Does anyone have any thoughts on this?

People are more prone to have events in REM. Even so, though, your overall numbers and how you feel both support treatment. Which is why you're here!

Paper_Nanny wrote:If I could set my ASV to perform like a regular BiPAP, would it make sense to try that in order to get my residual hypopneas and/ or low patient triggered breath percent looking better?

The act of configuring the ASV to act like a BiPAP should not, in and of itself, improve your situation. However, changing some of the settings on your ASV could yield improvement (or they may not). I'm not trying to be wishy-washy here; we just don't have any way to know ahead of time given the available data.

Let me try to break it down a little more simply. Our ASVs do everything a BiPAP does, plus some extra:
* A standard BiPAP will not dynamically adjust pressures; our ASV will. (And an Auto-BiPAP will too.)
* A standard BiPAP does not feature servo-ventilation on top; our ASV does. (Unique to us.)
* A standard BiPAP does not have a backup rate; our ASV does. (A BiPAP S/T does this too.)

The backup rate kicks in when you fail to take a breath (we're usually talking about central events here). See all those places where your patient-triggered breaths plummet? Without the backup rate part, the machine can do nothing for you. You simply...don't breathe. That's why ASVs and BiPAP S/Ts (the S/T stands for "Spontaneous/Timed" -- if you don't breathe spontaneously, the timed part kicks in) are the treatments of choice for central apnea conditions. Going to a straight BiPAP will generally not address central apneas.

The auto-adjusting part is what lets your EPAP and your IPAP vary. EPAP should be high enough to prevent obstructive events; IPAP increases are typically used to deal with hypopneas and flow limitations. Unlike the previous models of ASVs by Respironics, when when they made ours and the new System Ones, they wrote algorithms to let EPAP vary as well, to allow dynamic treatment of obstructive apneas. This is why the previous Respironics titration protocol was adamant that patients needed a solid CPAP or BiPAP titration to establish their baseline pressure before being titrated on the ASV, whereas with current models, that recommendation is relaxed.

Paper_Nanny wrote:Respironics Rep's advice to switch me from my BiPAP ASV to a straight BiPAP, set at 5/15.

Oh yes, your question! If you want to try this, I see two options, although before I lay them out, I'd say those pressures sound a bit weird to me because of the huge gap in pressure support.

OPTION A: Try his settings, but really use them as minimum pressures only. Let the ASV do what it's designed to do to prevent events. The settings to accomplish this would be:
min EPAP = 5
min PS = 10

This would ensure your ASV always has an EPAP at 5 or higher, and that it always has an IPAP at 15 or higher. The ASV will be able to raise EPAP in response to obstructive events, and it may increase your IPAP above 15 for hypopneas.

My hunch is this won't help, and you might even see your PTB drop more. If it does improve, it doesn't mean that BiPAP was better; it just means your ASV needed different settings.

OPTION B:
If you really want to do "exactly" what they asked for, then these would be the settings to use:
min EPAP = 5
max pressure = 15
min PS = 10

That will keep your EPAP and your IPAP locked in place, so your machine will behave like a BiPAP S/T (i.e., a BiPAP with the backup rate).

Paper_Nanny wrote:Going back to a suggestion made by BrianinTN, I am going to change my pressure support to three

I think that one came from StillAnotherGuess. ResMed's titration protocol calls for increasing min PS to address hypopneas (interestingly, Respironics's does not), and that's been the conventional wisdom for a while. I hope it does work in your case, but it's not assured.

BrianinTN wrote:

Paper_Nanny wrote:Going back to a suggestion made by BrianinTN, I am going to change my pressure support to three

I think that one came from StillAnotherGuess.

Aw, geeze, Brian... Some things I read on here go in one eye and out the other, but your suggestions don't. I particularly remember you saying that about the pressure support because you groaned when you mentioned it. And I wondered to myself, "Did Burrhus Frederic groan when the pigeon randomly pecked at the bar which released a bit of bird reward to him?" As I wondered about that, I turned and patted my dog Ralph on the head and reminded him that even Ralph gets the answer sometimes. We tell him that to make him believe that he, too, is capable of being a Good Dog, even though we secretly suspect it is only through random chance that he gets the answer. Breaking my nose, however, was most definitely the result of premeditated, logical, well reasoned thinking on his part.

But enough of that... This is from your post on Friday 17 June 5:05 AM

BrianinTN wrote:Also, while mentioning this makes me groan, the lab kept your pressure support at a minimum of 3, while your ASV at home isn't doing that right now -- so perhaps in your particular case the higher IPAP was useful in addressing some of your hypopneas. There is insufficient data to draw that conclusion at this point, however, and with your home data looking so good, I definitely would not tinker there any time soon.

So, with my home data not looking so good any more, and me not feeling so chipper and perky, I set the pressure support to 3 last night. My AHI went down to 2. I will be interested to see what happens over the next few nights. When I changed my EPAP min, my AHI initially looked much better, but then got worse over time.

Maybe what my body likes is the novelty of new settings? Maybe I will find my happy breathing- while- I- sleep place by changing my settings every week of so? Maybe what my body would also like is for me to replace the velcro on my head gear. The closure on the left side came loose last night and got tangled all up in my hair. Detangling it was not what I wanted to be doing in the middle of the night, but I did it. I am committed to making my treatment work.



And some trend data--

Paper_Nanny wrote:Some things I read on here go in one eye and out the other,

If things you're reading on here are going out of your eyes, you might have a bigger problem on your hands than just sleep apnea.

Paper_Nanny wrote:I particularly remember you saying that about the pressure support because you groaned when you mentioned it.

Yeah, I was groaning because I was forced to give a nod to what StillAnotherGuess had said, which ripped apart the fabric of my being. Like I mentioned in my preceding post, it's definitely documented that increasing min PS (which increases min IPAP) could help with residual hypopneas. My disdain was the matter-of-fact and "this will certainly work" way in which increasing min PS had been suggested. It's a little less cut and dried than, say, increasing EPAP to address obstructive events.

Paper_Nanny wrote: As I wondered about that, I turned and patted my dog Ralph on the head and reminded him that even Ralph gets the answer sometimes.

Smart dog. When I was growing up, we named one of our cocker spaniels Sasha. There were two reasons for this. The first was a reference to the way she sashayed her butt from side to side when walking. The second was because my parents had been watching a news program with an anchor named "Sasha Foo," but she pronounced her name so quickly and with such an accent that it sounded like "Such a Fool." Needless to say, Sasha was not a smart dog.

Paper_Nanny wrote: So, with my home data not looking so good any more, and me not feeling so chipper and perky, I set the pressure support to 3 last night. My AHI went down to 2. I will be interested to see what happens over the next few nights.

Me too. Looks pretty good. What I really like is that your hypopneas dropped despite your PTB being low for a lot of the night. Your pressure lines look pretty flat too -- almost like they would on a BiPAP S/T, but shhh, I won't tell anyone if you don't.

The leak monster bit you during your first few hours of sleep. Hopefully that's just an anomaly. Related to your velcro problem? You settled in nicely by hour 4.

EDIT: I foolishly forgot to ask the most important question of all. How did you feel this morning and today?

BrianinTN wrote:Yeah, I was groaning because I was forced to give a nod to what StillAnotherGuess had said, which ripped apart the fabric of my being. Like I mentioned in my preceding post, it's definitely documented that increasing min PS (which increases min IPAP) could help with residual hypopneas. My disdain was the matter-of-fact and "this will certainly work" way in which increasing min PS had been suggested.

Yeah, my references to B. F. Skinner, Skinner's pigeons, and my dog Ralph were meant to imply that saying, "Increase the min PS" could have been a right answer by purely random chance, rather than any well thought out reason. If someoone answers, "Increase the min PS" to every xPAP question involving hyponpnea, eventually, that will be the right answer.

BrianinTN wrote:When I was growing up, we named one of our cocker spaniels Sasha. There were two reasons for this. The first was a reference to the way she sashayed her butt from side to side when walking. The second was because my parents had been watching a news program with an anchor named "Sasha Foo," but she pronounced her name so quickly and with such an accent that it sounded like "Such a Fool." Needless to say, Sasha was not a smart dog.

That's pretty funny. I like stories about how pets get their names. And even being a not so smart dog, Sasha probably did get the answer sometimes.

BrianinTN wrote:Me too. Looks pretty good. What I really like is that your hypopneas dropped despite your PTB being low for a lot of the night. Your pressure lines look pretty flat too -- almost like they would on a BiPAP S/T, but shhh, I won't tell anyone if you don't.

Ummm, yes, please don't tell anyone. I don't know if you should have told me, in fact. Especially not with my new wave form data capable machine on the way. I got a call from the DME RT on Friday. She said she had ordered the machine and when it got delieverd, she saw that it was not the right one. The machine she received was the one I already have.

BrianinTN wrote:The leak monster bit you during your first few hours of sleep. Hopefully that's just an anomaly. Related to your velcro problem? You settled in nicely by hour 4.

Yes, the velcro problem. When I woke up and went to the bathroom to fix the problem, the strap responsible for keeping most of the left side of the mask was no longer doing its job. It was just flopping about, doing nothing useful. I sewed some new velcro on the headgear awhile ago. Pain in the butt!!! The only velcro I had was the kind with the sticky tape on the back to hold it on. It kept getting all gunked up on my needle and on the thread. Jammed up my sewing machine and even got jammed up on itself when I switched to hand sewing. I got it on well enough for tonight, I think, and tomorrow I'll be getting the velcro with no sticky tape stuff on it.

BrianinTN wrote:EDIT: I foolishly forgot to ask the most important question of all. How did you feel this morning and today?

There are too many confounding variables in play for me to accurately answer that. Maybe in a day or two once other things settle out, I'll be able to say.

Deborah