Why doesn't APAP respond to apneas?

[Snoredog]

I would go for a new sleep study. Your pressure setting is higher than my morbidly obese father. Find a hospital based sleep clinic that does a full night titration study, rather than waking you in the middle and fitting you with a cpap.

sit back a while you might learn something Patient is not morbidly obese and the titration studies from the lab are found on the first 8 pages of this thread.

We are discussing the way a machine responds to a particular event, if you can't deal with that start your own thread or at least demonstrate the courtesy to have read the entire thread before commenting.

[dsm]

Snoredog said "I don't like IPAP working pressure bumping into that ceiling and like it even less when I see Periodic Breathing introduced."

That 1st bit bothered me too!.

What is actually happening during those periods of IpapMax is the machine is cycling between epap & IpapMax at the fall back BPM or the AUTO calculated BPM (can't recall which BPM one Bev settled on but recall it being AUTO). That can be a tad disconcerting to a new bilevel user. I keep coming back to Bev's headache she mentioned.

But, that one PB score doesn't worry me at all - I see them from time to time & being such a tiny one off events I ignore them .

DSM

#2 In my own charts you can see consistently that the time at IpapMax is short and passes quickly as PS resorts to normal.
Bev's data there could still refelect her anxiety with this new type of (bilevel) therapy use.

[dsm]

I would go for a new sleep study. Your pressure setting is higher than my morbidly obese father. Find a hospital based sleep clinic that does a full night titration study, rather than waking you in the middle and fitting you with a cpap.

sit back a while you might learn something Patient is not morbidly obese and the titration studies from the lab are found on the first 8 pages of this thread.

We are discussing the way a machine responds to a particular event, if you can't deal with that start your own thread or at least demonstrate the courtesy to have read the entire thread before commenting.

What Snoredog really meant to say was - "thanks sbouche for your obvious concern for Bev, but we already have the data you have suggested. It is in the start of the thread. Cheers Snoredog".



DSM

[dsm]

This data is my own & what I call an example of the good therapy this machine delivers.
In particular contrast the way PS reverts pretty quickly to normal after a PS cycle has
occurred.

Note the 'av tidal flow' & the 'av tidal volume' numbers. These are what I consider good.
These numbers tend to suit my height & weight. Bev's will be lower. I am not saying Bev's
data should look the same as this, just putting forward a contrasting set of data that helps
one view Bev's data.



DSM

[-SWS]

Bev, I realize I said earlier that I was going to give you my analysis of your second night's data. May I take a one or two day rain check on that? I think this thread is waaaaay top-heavy on play-by-play analysis right now.

Besides, Bev, what I'm hoping for is that you can generate data at those same settings for at least another night or two. Let's find out if your physiology settles into this modality even better than it has already. That also gives us peanut gallery warriors a chance to continue with our analysis as you generate two or three night's data at this setting.

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Snoredog, I'm glad to see what you said about limiting to a 10 cm PS regarding how high you might set IPAP max. My earlier 3 cm suggestion was to get Bev acclimated to minimal, fixed Bilevel cycling. She's already riding the high-spirited horse like a champ. Don't think she needs to desensitize to BiLevel at PS=3 cm considering last night's successful SV ride.

Okay, at this point what issues do we think we might be in analytical disagreement about? I'm not sure, but is one of those potential areas whether the ASV can differentiate central from obstructive events? What else? I'll flag tidal volumes calculated from the AVAPS literature as one potential area for discussion. What else?

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Doug, are there any analytical areas of disagreement that you and I want to continue exploring as Bev generates more data (hopefully)?

[jnk]

I guess I've been called worse things than a bifurcated dysregulated breather!

You were..... by Jeff/jnk..... in this very thread..... on page 8.
Hmmmmm..... sounds a little like Professor Mustard in the Conservatory with the Lead Pipe.

omg, I'd forgotten about what jeff said, in good fun. LOL!! . . .

Just for the record, it's all because of my exchange with that Ambien-pushing, green-tea-guzzling, quickly-becoming-addicted-to-her-SV Bev, that I have now been coffee-free, Benadryl-free, and alcohol-free since that post on page 8. Her good example has healed me. I have actually even taken up green tea, believe it or not. My wife and workmates can't believe it! The only vice now left me is my ongoing codependent relationship with my autobilevel machine.

There is something about this thread that really warms my heart. I hope Bev feels all the love from everyone posting, as well as from the many who are closely following this thread, all wishing and praying the best for her.

Bev, I have no doubt you will eventually get used to that machine. No need to rush it. It will happen. Don't count sheep jumping over a fence in your head tonight; count cpaptalk friends/family all clicking our mouses for you!

[dsm]

SWS,

I am more than happy at this time to go with the wise advice you just passed on to Bev.
Also I feel we have ironed out any issues re what makes PS support work & am happy as to your whys.

Re this point "whether the ASV can differentiate central from obstructive events" I am sure we agree that it can't as long as we
make it clear that an 'obstructive hypopnea' appears as no different from a 'hypopnea' as far as ASV is concerned. Any 'no flow'
event (I assume this means under 100ml) will be treated as a central & PS will be applied at the AUTO calculated rate or the set
backup rate.

I am sure we agree that the SV algorithms rely on the titration of epap to have dealt with conventional obstructive apnea events
so it can treat any irregular fluctuations of volume that PS addresses and any irregular breathing rate.

Cheers DSM

[StillAnotherGuest]

I would go for a new sleep study.

Actually, that's not such a bad idea.

Both of the NPSG were noteworthy for their lack of REM, undoubtedly due to the Lexapro. Further, Lexapro can also cause significant sleep fragmentation. Thus, one wonders what the value of either of them were in really analyzing sleep (back on the "another cause for the EDS" bandwagon).

BTW Bev, do have any symptoms of narcolepsy (cataplexy, visual or auditory hallucination at sleep onset or awakening and/or sleep paralysis)? While Sleep-Onset REM is a hallmark of the disease, it could easily have been hidden by the Lexapro. It's seems a lock that you have the other symptoms (the EDS and sleep fragmentation).

I am still sooooooooooo curious about the severe desats in the Split Study PSG (and to an extent, in the Titration). They certainly have the appearance of being REM-related (REM can be suppressed, but not necessarily entirely eliminated). And if that were REM, then it would also be relatively early onset and give more support to the narcolepsy angle.

Further, understanding what happens in REM would give a much better idea on treatment course. If events in REM were few or mild, then you could make the case for "central dysregulation" (which really doesn't happen in REM). If the SDB is largely REM-related with severe sleep fragmentation and sleep-maintenance issues, then ASV might not be the greatest idea (the BiPAP Auto might be a better algorithm).

Here's a technical question. If you have the Back-Up Rate turned on, and it's set at a rate of > 6, then how many events would you actually "see", regardless of their origin?

Find a hospital based sleep clinic...

It's a center!

SAG

[-SWS]

Doug, I don't see anything in your summary above that I disagree with.

The suggestion for a sleep study is a great one IMO as well. Re: SAG's rhetorical question about events seen at BPM rates > 6... That > 6 time frame gets into the 10 s definition of hypopnea. But if you don't see it because it's been ventilated, then theoretically you missed seeing it because it's presumed to be a successfully treated hypopnea. Granted that presumption doesn't factor all pathology scenarios and therefore will be flawed lacking a proper diagnosis. However, you will see residual hypopneas that just didn't respond to ventilation, or went unresolved for lack of a proper pressure/flow target calculations from the algorithm.

[Snoredog]

Okay, at this point what issues do we think we might be in analytical disagreement about? I'm not sure, but is one of those potential areas whether the ASV can differentiate central from obstructive events? What else? I'll flag tidal volumes calculated from the AVAPS literature as one potential area for discussion. What else?

I don't think there is any disagreement on the central/obstructive differentiation ability, I think both types are included in Apnea Period count, I don't have EncorePro where I can easily confirm the AP=Apnea Period, but my guess is that is what they mean.

I would like to know why she went into Periodic Breathing? and how that can be prevented as I see that as a sign of instability just like central dysregulation (must be that bifurcation point you were talking about). I know the machine did what it was supposed to in the presence of PB but it seems we have gone to the opposite end of the scale per say.

What happens to Inspiration Time in Auto SV mode? Does the SV just target peak and volume with pressure support and/or does it also manipulate IT to also control peak?

[OutaSync]

Yes, I agree that more data would be good. I'll try to get some good sleep tonight.

Marcia and RG,
Thank you for the kind words. It's people like you that jnk is referring to when he talks about the warmth.

jnk, good for you! Eating healthy isn't all that bad. Green tea is a good start.

Thanks, all,

Bev

[Snoredog]

I would go for a new sleep study.

Actually, that's not such a bad idea.

why that is what we would expect to hear coming from a PSGT , but If not mistaken, I think she mentioned her doctor had already exhausted this years allotment of insurance approved PSG's. He thinks she is doing just fine.

While her Aflex report doesn't look all that bad (didn't I mention that?), she still has excessive daytime fatigue. Does she have CSDB? sorta looks like it.

Don't know if it helps SAG, but Bev mentioned she once tried Melatonin and had to stop it because of vivid dreams. Since melatonin is thought to encourage REM could it be she has a problem going into REM?

[dsm]

Okay, at this point what issues do we think we might be in analytical disagreement about? I'm not sure, but is one of those potential areas whether the ASV can differentiate central from obstructive events? What else? I'll flag tidal volumes calculated from the AVAPS literature as one potential area for discussion. What else?

I don't think there is any disagreement on the central/obstructive differentiation ability, I think both types are included in Apnea Period count, I don't have EncorePro where I can easily confirm the AP=Apnea Period, but my guess is that is what they mean.

I would like to know why she went into Periodic Breathing? and how that can be prevented as I see that as a sign of instability just like central dysregulation (must be that bifurcation point you were talking about). I know the machine did what it was supposed to in the presence of PB but it seems we have gone to the opposite end of the scale per say.

What happens to Inspiration Time in Auto SV mode? Does the SV just target peak and volume with pressure support and/or does it also manipulate IT to also control peak?

Snoredog,

I am pretty sure I have SV data somewhere that states it tracks rate as well, also within the 4 min tracking window. When the rate falls outside the target & if BPM=AUTO it uses averages to set INSP & ratio & then uses cycling and PS to bring the sleeper back in line.

I am confident in saying it tracks and responds to
1) flow
2) rate

In fact zero flow (a central) is a zero rate of BPM - it is safe to say the machine uses the same basic mechanism to deal with a no-flow central as it does with a a variation outside the target rate be it AUTO controlled or a backup rate.

DSM

[Songbird]

Just for the record, it's all because of my exchange with that Ambien-pushing, green-tea-guzzling, quickly-becoming-addicted-to-her-SV Bev, that I have now been coffee-free, Benadryl-free, and alcohol-free since that post on page 8. Her good example has healed me. I have actually even taken up green tea, believe it or not. My wife and workmates can't believe it! The only vice now left me is my ongoing codependent relationship with my autobilevel machine.

Jeff! That's incredible!! And you're still putting complete sentences together. I'm overwhelmingly impressed. (How are YOU, by the way? Still concerned. Still praying.) Have you tried ICED green tea? Nectar of the gods!! (I'm serious.... love the stuff.) Vices? I have a few left (if I'm not careful, this OSA thing and this wanting-to-do-well-so-I-can-make-the-forum-proud thing are going to force me into becoming a disciplined person, and I can't hardly stand the thought. ), and one of the top ones is my ongoing codependent relationship with this forum. This thread in particular illustrates many of the reasons. As you said,

There is something about this thread that really warms my heart. I hope Bev feels all the love from everyone posting, as well as from the many who are closely following this thread, all wishing and praying the best for her. Bev, I have no doubt you will eventually get used to that machine. No need to rush it. It will happen. Don't count sheep jumping over a fence in your head tonight; count cpaptalk friends/family all clicking our mouses for you!

You are so right, Jeff. At first blush, one might think that three of our group in particular might need to get out more , but not only are they having this discussion simply because they love this stuff, they're doing it for Bev. That alone is pretty amazing, when you think about it. Then there are their personalities, which only add depth to all of this. (By the way, Snoredog, I love your avatar!! )

Steve, Snoredog and Doug, even though most of what you guys are saying is worlds beyond my comprehension, I've read every word. I expect others are in the same boat. Maybe it's just the many years of oxygen deprivation , but I'm finding this stuff fascinating. And like you said to someone else, Snoredog, as I've been reading, I HAVE caught some of the concepts and learned a little. (Don't tell ME there aren't any more miracles!! ) More than that. The WAY you're discussing it is a lesson, in and of itself. For the most part, even though you've strongly disagreed on a number of points, you're limiting the disagreements to WHAT is being said rather than WHO is saying it. Okay, there have been a couple of near-disasters, but you even got past them. High marks, guys. You definitely get my vote for .

In closing, I told a dear friend of mine that I wasn't going to share a particular thought, but I've changed my mind. On the other hand, recalling several thousand times in my life when my intent didn't come shining through and someone thought I was being snotty, nasty, etc., I'm going to qualify my thought before sharing it.

NOTICE: Please file the following thought, which has occurred to me several times during this particular discussion, under HAVING fun, not MAKING fun; GOOD-HEARTED TEASING, not COMPLAINT; the kind of fun you'll only find in a tight-knit group of highly cherished people, be it family or friends: https://www.youtube.com/watch?v=1_47KVJV8DU

Carry on, boys.
Marsha

[dsm]

Couple of extra points

Firstly I have looked everywhere I can to locate the data I have that states that when a no-flow situation arises (SV will treat this as a central & fall back to the current AUTO target or the set backup rate) that it uses PS as well as cycling. I know I did a test a week or two back, so again tonight I'll try another test that should provide clear proof. This will be to set a backup rate of 4 (lowest), raise IpapMax to 30 (highest), set epap to 4 (lowest) and IpapMin to 6, then run the machine with the mask held against a pillow (I want the mask vents to work as normal but obviously there will be no breathing - simulating an extended central). If I run that for 5+ mins the activity should show clearly on the Encore report - I will expect to see the cycling (pressure changing epap to ipap) but am also expecting to see the ipap pressure rise like steps each cycle until 30 CMs is reached and to stay there at 30 CMs. If granular enough it (encore) should show the BPM cycling at 4 breaths a minute and the changing pressure quite clearly. It just occurred to me that I will be demonstrating what used to happen to our member dllfo (who has a BipapSV).

Also here is another SV chart that I consider one of my worst nights (according to the data) but for me sleeping it seemed pretty much like any good sleep night. In the data there is massive leaks (early on), Periodic Breathing (several times), AIs, HIs - but a pretty good peak flow and a pretty good av tidal volume. Total AHI scored was 4.0. One reason for this chart is to show Snoredog some more serious PB scoring than what Bev's chart showed and why I commented that one PB score is not worth bothering about.

http://www.internetage.ws/cpapdata/dsm- ... -bad-1.jpg

DSM

PPPPPS
#999 Also this link is an important factor in understanding some of this thread a must see
http://au.youtube.com/watch?v=XRLPI47BL0c&NR=1

PPPPPPPPPPPS Revised !!!
Based on trials whatever you do, don't listen to the link posted in the post ahead of this one
(you will never get it out of your head, not even if you play the antidote link)