BILEVEL PAP Therapy Pearls: Clearing the First Hurdle

StillAnotherGuest wrote:
<snip>

Darn, I'm stuck already. If I want to post a link to a graph, should I put ***CAUTION - CONTAINS GRAPHS*** in the Post Subject or put the link in blue?

SAG

SAG,

Just PM me with it if posting it here causes angst

Cheers

DSM

dsm wrote:Allowing for where this has led, did you PM Dr K ? - (I would hope so).

No. "Dr. K" made it clear earlier in the thread that that was not an option:

BarryKrakowMD wrote:Quick Heads-Up on Personal Messages

I do not object to receiving Personal Messages, but I must explain why I cannot respond to them.

dsm wrote:Just PM me with it...

Why? Did you take a class in Swahili?

OK, here's the thread where Expiratory Adjuncts were covered when EPR first hit the market, and musings how EPR might affect airway stability.

The New Rule is links to posts with graphs will be in red, so get ready!! Hide the children!!

An Analysis of EPR and CFlex

SAG

Rested Gal,

I at last had some time to get out the various Bilevels & confirm their ipap to epap switching and all of them do as you say (incl Healthdyne, Bipap Pro II) which is to switch to epap after approx 3 secs (give or take a little). I believe his also confirms what was said at the link I provided that most Bilevels are hard coded for a max 3 sec ipap phase.

As a sidenote - in prior posts when I say 'slowly stopping breathing'. I am meaning breathing out slowly and 'gently' slowing the exhale until there is no air flowing (this is something that happens for me sometimes esp if on my back, there are a number of explanations which I won't go into here but it happens).

As another sidenote when I say ipap I am meaning Inhalation pressure & by epap am meaning exhalation pressure ...

Re the EPR feature on my Resmed Vantage. This is where my experience seems different to your observations. The EPR feature really does act like a timed mode BiLevel. First let me explain why this test matters to me. I use a full face mask because I tend to switch between nose & mouth breathing as I get a lot of nasal flow restriction.

Typically when I nose breathe, will tend to take (I guess) long slow breaths - just can't get the air in faster. I have been using nasonex and on occasions Otrivin to try to open my nasal airway. The slower breaths will often be 4 to 5 secs long +/-. That would explain why I always had difficulty with the BiPap (Pro II & Auto) units as these (from what I understand) are set to a max of 3 secs ipap so will switch to epap while I am still wanting to breathe in. I have read comments from many people over the past few years where they too comment on Bipaps switching to epap too early. The Knightstar PB330 and the Vpap IIIs units haven't given me that problem.

Re EPR, this feature allows long slow inhaling and exhaling & on exhale no matter if I try to disrupt it by slowing noticeably & stopping breathing, the machine will, well within a couple of seconds, revert normally to ipap mode - again.

Restated, no matter how I exhale, once I stop exhaling, the EPR feature reverts to normal pressure. If I deliberately try to slow an exhale up to the point of stopping air flow, the machine *always* goes back to ipap normally and when I try to stop exhaling - it goes back to ipap within a couple of seconds. Also, under these situations EPR doesn't disable itself but works again on the next breath. When I said in an earlier post that the EPR was canceling when I stopped exhaling, I was wrong, it just ends normally. canceling was quite the wrong word.

In many runs of testing & timing the *whole exhale cycle* I couldn't get the EPR to stay in EPR (epap) for longer than a couple of seconds after ending the exhale. Normally, the EPR reverts to ipap right at the end of a normal exhale.

I revisited the data from Resmed on the EPR feature & my understanding is that it will cancel (disable) the EPR if the machine detects OSA but my breathing out slowly & stopping is more akin to a central & as mentioned EPR on my machine will within *a couple of secs* of the end of my exhale (say exhale = 4 to 5 secs), start moving back up to the normal inhale (ipap) pressure - *and* continue on as normal (ipap - epap - ipap - epap). This happens repeatedly & predictably.

This is close enough to how a timed mode bilevel works that I feel confident in describing it as being 'like' a timed bilevel, as I have here in the past. My PB330 will switch from epap to ipap after 4 secs from exhalation cessation if I try the same test as I did with EPR. In fact there is little difference in how the two work when set with a gap of 1 2 or 3 CMS other than the lack of risetime adjustment on the EPR machine.

It would be interesting to hear what others find when they try slowly stopping breathing while say using EPR=3 (as explained above). I believe they will find it works is pretty much as explained above. My settings are cpap=13 & EPR = 3.

Cheers

Doug

Once again, -SWS, I come back to you with hat-in-one-hand and a Subway Thin-Sliced Crow Sandwich in the other.

You told me to think outside the box...

-SWS wrote:Absolutely no disrespect, sir... But that's what any subscriber to a biologically-mechanistic paradigm with a linear problem-solving approach might "have". I believe that type of paradigm and linear approach to be absolutely essential in science. However, it doesn't necessarily work well regarding exploration of a largely unknown behavioral/cognitive side of the autonomic sleep bridge. Rather, it politely says: "Everybody needs to get back on the biologically mechanistic side of the bridge and resume thinking inside the mechanistic box."

But did I listen? Noooooooooooooooo..............

For over a hundred posts in this thread, and 20 years before this (I'm "somewhat" older than I look), I have said "Watch out for cardiac oscillations, they can really mess you up". Cause other than Rapoport, Norman, et al and the PB420E, nobody really got much benefit from looking at 'em.

So last night, I sees this commercial where a young woman is walking out to her car in the middle of the night, all alone in a deserted parking lot. She looks at her electronic car key, sees a flashing red light and thinks to herself, "Aha!! Jack-the-Ripper is in the back seat of my car!!" and runs off to safety. (Course, one would have thought that maybe some other alarm would have sounded before that point, but that's the "scientific" me.)(Or better yet, a young woman walking out to her car in the middle of the night, all alone in a deserted parking lot, doesn't need an alarm system, she needs a lobotomy.)

So somebody took this:



...and, using this phenomenon (ballistocardiography) did this...



and now is probably a zillionaire.

Well, I'll show them! I am working on a system where, when cardiac oscillations are seen on a pressure transducer, an alarm will sound to alert the user that Jack-the-Ripper is on the other end of the CPAP machine.

Am I "out of the box" or what?

SAG

Yikes!

Did you notice the ghostly image in the window of that car, which is standing in broad daylight?

O.

SAG,

Interesting info

Reading that brought to mind a graph of mine from 2006.

http://www.internetage.com/cpapdata/menu_0815.html

Now do those spikes qualify as cardiac oscillations, nightmare peaks or evidence of regularly spaced very nice dreams.

Joking aside, I never did get any comments as to why these spikes would occur with such regularity and with such short bursts of such high jumps.

Cheers

DSM

[quote="-SWS"]"Cause vs Epiphenomenon"-I'm still wondering about those stretch receptors. I'm wondering whether "optimally patterned" stretch can have a mitigating effect--even when stretch-related receptors are presumably neither cause nor epiphenomenon.

Again I'm digging for parallels. I'm once again thinking of a mother, instinctively trying to sooth her crying infant. The child is crying for a reason unknown to the mother. Rocking has worked so often in the past, that the mother occasionally makes use of a small indoor swing. This time the mother places her crying infant in the swing. She repeatedly places her hand against the child's shoulder, gently swinging her child until the crying is eliminated.

Here the mother discerned neither the cause nor the epiphenomenon of the situation. She applied her mitigating technique to the infant's shoulder. While the infant's shoulder is certainly a physiologic mechanism, it most certainly was neither cause nor epiphenomenon.

However, anxiety was clearly involved here. So was maternal instinct. And maternal instinct is arguably a case of innate behavior very efficiently solving some extremely tough problems. Here the mother instinctively relies on a soothing rocking pattern to stabilize her infant's disturbed emotional state. The infant was crying and even happened to manifest highly disrupted breathing. The mother's rhythmic technique stabilized all that. And instinctive rocking is the same technique she uses to induce sleep in her child at bedtime.

Why do central apneas in CPAP-intolerant patients sometime resolve with BiLevel? Can rhythmic vagal input mitigate hypothetical anxiety-related central apneas (even when stretch receptors are presumably neither cause nor epiphenomenon)? Can yet other types of rhythmic or soothing neural input mitigate anxiety-related central apneas?

Does anybody have more ideas for Dr. Krakow? I admit that mine are far out there and pretty strange. So what's new?

А есть, какая нибудь альтернатива?