Why doesn't APAP respond to apneas?

[-SWS]

If Bev could get hold of a bilevel machine, and I think she can....

What you have in mind would be nice!

[rested gal]

In the meantime... Bev, are you game for asking the place where you had your sleep study to give you CD copies of your studies? The raw PSG data on CD. SAG's offer is a fantastic opportunity for you to receive an extremely knowledgable "second opinion" about your previous sleep studies.

From page 11:

Any chance on getting a hold of the raw data discs (the actual sleep studies themselves)? Speaking of a fishing expedition, I'd like to go on an alpha intusion hunt.

SAG

[Snoredog]

Snoredog, CPAP + SV would entail IPAP min also being set at EPAP's value.

If it were me I would also eventually go back to trialing SV---but only after learning how to sleep and feel extremely comfortably with the small, fixed pressure cycling of ordinary BiLevel (thus with IPAP min and IPAP max both set only 3 cm above EPAP). Then once I was very comfortable with that fixed BiLevel pressure cycling, I would re-trial SV---first with auto BPM, and then with manual backup and IT settings.

Absolutely positively catch up on sleep with the old APAP machine first IMO.

Never did find out what rise time Bev is using.

I thought if IPAP and EPAP differential was 3 or less that was still CPAP (i.e. EPR for example). My thoughts with the 14 cm pressure is we would be at her AFLEX pressure settings where 14 to 17 cm range the outcome wasn't all that bad but we could see how SV might improve her fatigue (in the back of my mind I think she has a tiny bit of UARS and well that PS might just resolve those spontaneous critters for less fatigue). But then on her PSG's they showed her spontaneous arousals low at only 3.1 per hour, since mine is like 30 hr, I figured that was nothin

My other thought was if we stayed close to CPAP with those settings we might be able to avoid the PB. Any central dysregulation would be controlled by the fixed backup settings.

Rise time: 1-6 with 6 being the slowest, I'd try 3 for starters, not sure but I think in SV mode it is handled by digital autotrak, but it is a user changeable setting.

I'd like to see her try the same settings as her Aflex with the 4 cm max pressure support. If she uses the fixed backup BPM=10 and IT=1.2 we can be pretty assured it will eliminate any central dysregulation seen.

Is there anything you have seen on her reports that would suggest Chronic hypoventilation? Because if that is the case the SV machine is contradicted for those patients (section 2.4 in the manual).

[OutaSync]

"Bev, I'm still of the highly-speculative impression that you're a "tightly strung" or "neurologically defensive" sleeper. I think any set of disruptive stimuli is inclined to devastate your sleep architecture. That means GERD, pain, aerophagia, unfamiliar environmental input (new surroundings, new sound, etc.), and now the pressure pulsing of auto SV can account for deteriorated sleep and even defensively-dysregulated breathing at times. "

I think that describes me well. I've always had a hard time sleeping in strange places or when everything isn't as it should be, i.e. guests in the house. Sometime in the early morning I am sleeping well enough that once I didn't even hear the neighbors garage sale! When my alarm goes off during this, it's very hard to wake up.

"Never did find out what rise time Bev is using."

Is rise time the same as IT? Rise Time was set for 3. I didn't see any way to set IT

"In the meantime... Bev, are you game for asking the place where you had your sleep study to give you CD copies of your studies? The raw PSG data on CD. SAG's offer is a fantastic opportunity for you to receive an extremely knowledgable "second opinion" about your previous sleep studies."

Yes, I will do that.

"Has your doc ever tried you on Xyrem?"

No,he hasn't mentioned that.

I'm really tired today, head hurts, chest hurts, can't concentrate on work.

Bev

[Snoredog]

Bev: Don't forget you are bifurcated too

don't feel bad, when I search up some of the words SWS uses, they show up under that Scolarly google thingee, when I search for words I've used, they show up under you really are dumber than a 5th grader google thingee.

[OutaSync]

Thanks, Snoredog, that made me laugh, and I needed that!

Also love your avatar.

Bev

[OutaSync]

I just got off the phone with my sleep center. They told me that they do not give out anything but the 3 page report. I told him I needed the raw data for a second opinion and he said he would check with the head Dr. and call me back.

Bev

[Songbird]

Bev: Don't forget you are bifurcated too

don't feel bad, when I search up some of the words SWS uses, they show up under that Scolarly google thingee, when I search for words I've used, they show up under you really are dumber than a 5th grader google thingee.

Me, too, Snoredog!! I'm very comforted to be in such good company. Won't tell you what I initially thought "bifurcated" meant. Let's just say it had nothing to do with science.

Marsha

[Guest]

Bev: Don't forget you are bifurcated too

......I don't even want to know what the therapy is for that.


..........that doesn't involve any kind of probe , does it???

[dsm]

Snoredog, CPAP + SV would entail IPAP min also being set at EPAP's value.

If it were me I would also eventually go back to trialing SV---but only after learning how to sleep and feel extremely comfortably with the small, fixed pressure cycling of ordinary BiLevel (thus with IPAP min and IPAP max both set only 3 cm above EPAP). That gets away from wondering which events might be SV induced. It also gives Bev a chance to find the best fixed IPAP and EPAP values that address her obstructive components.

Then once I was very comfortable with that fixed BiLevel pressure cycling, I would re-trial SV---first with auto BPM, and then with manual backup and IT settings. I would use the above determined EPAP as SV's EPAP. And I would use the above determined IPAP as SV's new IPAP min. I would experimentally set IPAP max at no higher than 10 cm above the EPAP value. Again, I'd give auto BPM another shot before heading off to manual BPM and IT settings. I'd at least initially employ whatever rise time I found most comfortable while running at fixed BiLevel.

Absolutely positively time to catch up on sleep with the old APAP machine first IMO.

Never did find out what rise time Bev is using.

This seems to me to be the safest path at the moment. Bev's latest night's data shows *no* improvement just decline.
At least Bev can set the machine up as either CPAP or Bipap (no PS) but still get familiar reports.

The data recorded though, is really not granular enough to detect even the epap-ipap fluctuations - in my tests they just showed as bars. Also it seems the SV has two particular PS algorithms (Ive been searching the patent #s on the machine to try to find them) in my tests there was one mode where the epap-ipap cycling was regular but with ipap increasing by 2 CMs until approx 10 above IpapMin. Then there was another modality where the machine did short 'puffs' with each new puff being 2 CMs higher. I am assuming one modality is for dealing with central dysregulation & the other (the 'puff' mode) for periodic breathing.

DSM

[-SWS]

Speaking of bifurcation during Bev's two titration studies: she experienced no central dysregulation on CPAP; however she did experience central dysregulation on BiLevel. So the actual BiLevel pressure cycling itself may very well have been sufficient stimuli to cause central dysregulation. In light of that, I'm not surprised that Bev found the much larger and more erratic pressure pulsing of SV therapy even more disconcerting.

In my mind the big question will be whether a patient like Bev can eventually find BiLevel pressure pulsing to be comfortable. If so, then there's a chance that SV therapy may be able to correct episodic (a.k.a. bifurcated) central dysregulation when yet other disconcerting stimuli are presented. If so, SV may end up being the best modality for Bev after a certain adaption period. Could be entirely wrong about that "neurologically defensive" stimuli-based theory.


Snoredog, the SV contraindication with hypoventilation has to do with the algorithm's downward skewing of running flow targets---which in turn generate under-treatment. Here, Bev is receiving the opposite algorithmic response: over ventilation via extended periods at IPAP max.



Did I ever tell you guys about the pirate who walked into a bar with a trifurcated-breathing parrot on his shoulder....?

[-SWS]

Then there was another modality where the machine did short 'puffs' with each new puff being 2 CMs higher.

The short 2 cm puffs are the machine's attempt to take a best indirect guess at whether an apnea is central or obstructive (one requiring more pressure to resolve than the other for identical under-target flow values). Following that best guess based on directly measured flow deltas immediately after those 2 cm puffs, the machine will then attempt a commensurate pressure response.

Not at all an accurate way to truly differentiate obstructives from centrals, but algorithmically helpful none the less. Knowing the measured flow delta in response to those preliminary 2 cm puffs helps the algorithm to make the correct pressure/flow calculations for targeting and resolution.

[OutaSync]

This is the response I got from the RT at my sleep center in response to me sending him the same page that you all looked at:

"It was nice to here from you again. Your download looks great, how did you feel this morning? I just got the one page (page 5 of 6). From looking at it, it appears to be working fine for you. If you could send the rest of the pages I could give you a better answer. Take care."

[-SWS]

Well, your RT's impression was also my first impression. Many of those measured parameters look good. However, frank PB was never mentioned on your PSG's, despite my suspicions you experienced irregular breathing not meeting PB scoring criteria. On the Encore reports you score PB, and that hints at the possibility of irregular breathing having gone from slight to worse.

The RT may not be familiar with analyzing that "pegged-out" IPAP peak trace if he doesn't work with autoSV very often. Regardless, I'm still of the impression that SV might serve you MUCH better once you get through a period of comfort or adaptation regarding BiLevel therapy. There's plenty of trial-and-error and analysis just ahead, Bev!

[-SWS]

Then there was another modality where the machine did short 'puffs' with each new puff being 2 CMs higher.

The short 2 cm puffs are the machine's attempt to take a best indirect guess at whether an apnea is central or obstructive (one requiring more pressure to resolve than the other for identical under-target flow values). Following that best guess based on directly measured flow deltas immediately after those 2 cm puffs, the machine will then attempt a commensurate pressure response.

Those quick short 2 cm pressure probes may currently be the most disconcerting sensory stimuli of all for Bev while using that machine.