BIPAP AUTO-SV SETTINGS HELP

[dsm]

One of the big challenges in a complex thread like this one is keeping the interactions polite (our egos are involved ).
If there is anything I have learned & am still learning in spades, it is in the value of polite interaction & remembering
the value of a smile. It can be hard to work out what someone else is thinking when they write particular words & that
can lead to misunderstandings. Then there is the problem of deliberately saying something that is confrontational,
sometimes in response to what seemed like someone else's confrontational comment. A difficult ground to be on.

I think some base rules have emerged in offering advice where the user has a complex machine (Bilevel S/T or ASV machine)
1) Absolutely refer the user back to their RT/Doc if they don't like their RT/doc encourage seeing another
2) Try to gather as much of the users circumstances as possible as often some details explain the problem
3) Avoid overloading the user with too much complex information & too many instructions
4) Only ever try incremental changes - avoid multiple settings changes

When people ask for help, it is very natural to assume they are ready for it. Many of us here want to offer what help
we can. The downside is if the 'help' is actually a hindrance & that is often difficult to see at the time. There is a high
degree of 'trier beware' involved.

DSM

[CROWPAT]

I am disappointed, of course, but still learned. Learning how to deal with this mess is imperative. 30 minutes with my sleep doctor yesterday just seemed to confirm that he knows little about SV/ASV treatment for complex apnea and he is honest enough to say so. His position is that few doctors focus on those machines because regular CPAP/APAP/BIPAP machines are used to treat the vast majority of patients. He is always interested in what I find out about how to use my machine and how I react to changes in machine settings.
Perhaps Muffy will find this thread at some point and provide a new perspective.
My thanks to all who have tried to help. I check the forum several times a day.
Pat

[-SWS]

I am disappointed, of course, but still learned.

Well, don't be disappointed just yet.

As we experimentally attempt to isolate your response trends to those individual machine-parameter variations, we might start to build a useful picture of which machine-based parameters yield highest dyscontrol

Those tell-tale 13/13/13 and 11/11/11 paired results just opened up a whole new avenue of hope regarding experiments toward beneficial treatment changes.

So far we have been focusing on CROWPAT's complex sleep apnea as if it were an SDB problem comprised of two opposite-vector disordered responses on a pressure-treatment scale. And that's essentially what you need for "permissive flow limitation" to work: some tolerable middle-ground pressure with intolerable obstruction sitting out-of-the-way albeit waiting at the low-pressure end of the scale, and an intolerable central component sitting out of the way at the high end of that same pressure treatment scale.

But CROWPAT's 13/13/13 and 11/11/11 experiments revealed something different about his central component: his periodic breathing tends to worsen at lower fixed pressures. And CROWPAT's sleep study summaries support that same observation. We now need to look at CROWPAT's complex breathing problem as if it were a three vector problem. Not the simple two-vector problem that can sometimes be much better solved with "permissive flow limitation".

Instead of viewing CROWPAT's physiologic response and proposed treatment experiments with: 1) greater obstructive severity waiting for him at the lower end of the pressure scale, and 2) greater central severity waiting for him at the higher end of the pressure scale, we can now assume this three-vector physiology model instead:

1) increased obstructive severity waiting for CROWPAT at the lower end of the CPAP pressure-treatment scale,
2) increased pressure-induced central apneas waiting for CROWPAT at the higher end of that same pressure scale, and
3) increased periodic breathing waiting for CROWPAT at the lower end of that scale

CSDB/CompSAS is an inherently hypocapnic disorder.... Meaning that a blood-gas CO2 shortcoming or deficit tends to trigger central problems. And typically, higher pressures exacerbate that hypocapnic tendency. But whoa! While higher pressures, indeed, induce CROWPAT's central apneas, lower pressures are specifically increasing his periodic-breathing rate.

As it turns out, there are many kinds of periodic breathing and there are multiple pathophysiologic reasons to trigger periodic breathing. When it comes to periodic breathing, sometimes a hypocapnic problem (CO2 threshold) is supplemented by a twitchy hypoxic or low-O2 threshold. Here, we might think more in terms of a disordered or relative low-O2 threshold with respect to triggering periodic breathing---as opposed to a hypoxic/hypoxemic cellular-damage focused O2-threshold paradigm.


So at 11/11/11 we can see CROWPAT's respiration becoming less volume-efficient and his PB increasing significantly compared to higher CPAP pressures.

In my next post I'll discuss how the above statement might be factored into CROWPAT's upcoming experiments...

[-SWS]

So at 11/11/11 we can see CROWPAT's respiration becoming less volume-efficient and his PB increasing significantly compared to higher CPAP pressures.
In my next post I'll discuss how the above statement might be factored into CROWPAT's upcoming experiments...

Apparently not... As I read several posts above, it sure sounds as if everybody is very politely closing up shop. I'm admittedly a little surprised by the sentiment in light of doctor-approval for CROWPAT's parameter-variation type experiments.

So is the consensus that we do NOT want to continue with xPAP parameter-variation type experiments----despite the CPAP testing portion having rather quickly flushed out a revealing pattern?

[CROWPAT]

I'm not closing out anything as long as you have ideas that make sense to me. Your 3 observations above make sense to me. What next?

[Guest]

In my next post I'll discuss how the above statement might be factored into CROWPAT's upcoming experiments...

Yes?

[-SWS]

CROWPAT, right now I would suggest at least a couple nights of recuperation at your favorite settings of 12/14-22/auto.

Perhaps Muffy will find this thread at some point and provide a new perspective.

That would be great. I've always had this far-fetched fantasy that Muffy, StillAnotherGuest, sleepydave, and NotMuffy would someday join forces and form an awesome SDB think tank.

What next?

Well, I think we should continue learning your physiology in response to careful xPAP parameter variation experiments.

Do you remember that three-vector SDB model I mentioned above? As it turns out your obstructive component, central apnea component, and periodic breathing component might not each contribute a nice, even 33.333% share to these following-day symptoms:

The one thing I have noticed on the BiPapAutoSV is that when my "Breathing on my Own" number is 99.9% I feel better even if some of the other numbers are not as good as usual.

So our parameter variation experiments tend to reveal response trends to various xPAP parameters. Each of your three SDB sub-components probably have their own unique optimal pressure settings. And after last night's 11/11/11 physiology-response test, we discovered a very prominent periodic breathing component. It seems to become emergent or more prominent with descending fixed pressure. So attempt to subjectively assess on a 1-to-10 or perhaps 1-to-100 scale how that periodic-breathing component might have contributed to today's symptoms. Did that PB make you feel unusually foggy-headed today? Or did it not make a significant impact on today's symptoms regarding that foggy-headed feeling you were hoping to improve?

When we get nights where PB becomes almost non-existent, but you have some typical high-pressure apneas, how will THOSE days subjectively compare with today's PB-based experience? So we can learn your physiology's immediate sleep-data responses to the various xPAP parameter changes. But you can also start keeping tabs on whether central apneas or PB happen to contribute disproportionately to your following day symptoms. We just might be able to adjust your BiPAP autoSV settings to steer clear of your most problematic pressure-setting parameter(s). But we need to methodically learn how your physiology reacts with the various CPAP, BiLevel, and SV parameters first. And that takes time. So we need to be methodical and patient.

In my next post I'd like to kick around the idea of CROWPAT comparing basal SpO2 at low pressures versus high. If his periodic breathing really is triggered by a slightly lower basal O2, then a supplemental O2 bleed added to a lower BiPAP autoSV setting might yield his best results yet:

He was briefly titrated to 20 cmH2O. He was changed to ASV and went 1 hour and 20 minutes with no obstructive events at an ASV pressure of 7 cmH2O. However, his breathing pattern appeared to be irregular on ASV

So above we have a low ASV pressure of 7 cmH2O addressing CROWPAT's obstruction but still yielding irregular breathing. Would love to know what CROWPAT's basal O2 happened to be at that pressure and a few others...

[CROWPAT]

I concur that the three elements you identified are unlikely to be equal contributors.
I was clearly affected negatively by the unusual amount of periodic breathing.
Lower PB yields better days (even with the inevitable fog that develops). Having 0 or near 0 PB is quite common for me at 12/14-22/Auto.
It took me months of experimentation to settle on those numbers as what was needed for minimal AHI - my focus until we started this.
100% patient initiated breaths (or even 99%) are always better days too.
On good days I awaken with the feeling that I am almost there with some feeling of an odd "slight pressure" inside of my skull that eventually turns into the usual daily fog.
Sleep onset with any setting is rarely more than 5-7 minutes unless I am troubled by mask leaks or under a great deal of work stress.
O2 levels during ASV titration are shown on page 4 of the 2007 report that I emailed to you.

[dsm]

Am prompted to ask this question re the normal settings that seem ok & following on SWS's observations,
Did you try epap=IpapMIN & IpapMAX=20+ at all when developing you current settings ? if yes what results did that yield ?

SWS do you have any thoughts on that epap/ipap gap minimum being set to 2 vs say 4 ? - reason I am prompted to ask is
that on my own experimenting, I am satisfied I was able to eliminate 2 years of regular cramps that I was getting (less so
on the Bipap AutoSV than on the Vpap Adapt SV) by spreading the Ipap/Epap gap from 3 to 4. The clue that prompted me
to try this was that the 2 machines with near to identical settings behaved very differently in these cramps occurring. I
attributed the more rapid control of the Vpap Adapt SV has possibly (my amateur guess) contributing to a pCO2 imbalance
and that by spreading the pressure (which is what I see the SOMNOvent CR does when controlling CO2), might be worth a
go. Now after 4 weeks*and from the 1st night of the change) no cramps at all. I could try reverting to 3 CMs gap & see if
they return. Am willing to try it as it was very much a case of not being certain why the 3 to 4 change worked so well. Am
wondering to what extent pCO2 is playing a part in CROWPAT's problems.

Cheers

DSM

[Muffy]

I've always had this far-fetched fantasy that Muffy, StillAnotherGuest, sleepydave, and NotMuffy would someday join forces and form an awesome SDB think tank.

I don't know about an "SDB think-tank", there, -SWS, but they do have (together with the other identities) a pretty good club softball team with good starting pitching and a bullpen to die for.

Perhaps Muffy will find this thread at some point and provide a new perspective.

I did offer perspective. Moe and Larry always do that.

However, in your defense, I figured it'd take about this many posts before you'd realize that.

What next?

Start scanning and posting all the NPSG data, or ask -SWS to forward it to me through our mutual friend. Include the medication list and the times you take them (especially the nighttime stuff).

No PLM in either study and O saturation remained about 90% throughout the night.

If saturation really remained at 90% throughout the titration night---and still remains that low---then I have to ask why the doctor(s) did not attempt to experimentally elevate CROWPAT's O2 baseline with supplemental oxygen.

Yeah, I thought at that point that was very significant information.

Muffy

[Muffy]

In your data download, you generally have about 9 hours of analysis period. If we divide this into 15-second Breathing Observation Periods (BOPs)(an average respiratory event time) there would 2,160 BOPs to see when you're doing well or not in re: SBD (assuming that event identification is correct and you are, in fact, sleeping).

When your D/L shows that you're doing well (like on 12.6.2009), you have about 6 events.

As soon as anybody can come up with a good reason that 2,160 stable BOPs would be "night and day" better than 2,154, then I'll support "dial wingin' ".

Muffy

[-SWS]

SWS do you have any thoughts on that epap/ipap gap minimum being set to 2 vs say 4 ?

No conclusions or even generalizations based on CROWPAT's unknown physiology at this point. And no generalizations for CROWPAT based on your individualized response to BiPAP autoSV. However, an observation that the Respironics BiPAP autoSV titration protocol defaults to an epap/ipap gap minimum of zero, which is closer to CROWPAT's 2 setting versus say 4.

What next?

Start scanning and posting all the NPSG data, or ask -SWS to forward it to me through our mutual friend. Include the medication list and the times you take them (especially the nighttime stuff).

CROWPAT, you just got very lucky. Muffy is sharp and manages a sleep center to boot. At this point, suspend the parameter variation tests and let's see what Muffy can spot on your behalf. Muffy usually comes up with some very useful advice.

As soon as anybody can come up with a good reason that 2,160 stable BOPs would be "night and day" better than 2,154, then I'll support "dial wingin' ".

My very strong preference is to not have to dial wing as well. However, 2,160 BOPs are usually in the eye of the beholder. And the common theme for so many patients on this and other message boards is that "BOP beholding" by the medical community seems to be remiss all too often.

That, in turn, is a big part of what places so many patients in the dilemma of having to dial wing. The Muffys, StillAnotherGuests, sleepydaves, and NotMuffys are in critical shortage in the real world. Plus, they occasionally need time off for softball and family. Thanks for stopping in to help out once again.

[Muffy]

Muffy usually comes up with some very useful advice.

Well, "IMHO", this old guy can really swing an axe...

https://www.youtube.com/watch?v=z2nQZPC ... re=related

Muffy

[-SWS]

Well, "IMHO", this old guy can really swing an axe...

https://www.youtube.com/watch?v=z2nQZPC ... re=related

Well that's refreshing. I thought it was going to be one of these:
https://www.youtube.com/watch?v=6wfOhilsQn8

The more I see about the complexity that some of us face, the more convinced I am it is important to engage my healthcare team as I try any experiments.

John, I wholeheartedly agree with that sentiment.

[Guest]

O saturation remained about 90% throughout the night.

If saturation really remained at 90% throughout the titration night---and still remains that low---then I have to ask why the doctor(s) did not attempt to experimentally elevate CROWPAT's O2 baseline with supplemental oxygen.

Yeah, I thought at that point that was very significant information.

The oxygen number was all my fault. I should not have relied on memory, and made a mistake by saying it was about 90 when I meant to say above 90%.