An APAP Shootout (sort of) on Academic Journal

[-SWS]

So far everyone very understandably has nothing but guesses about APAP efficacy. I agree there's a lack of adequate clinical data and even methodology regarding APAP efficacy. My view/guess may lie somewhere in the middle of Rested Gal's and GoodyUT's, but it's nothing more than yet another guess or opinion about APAP efficacy. However, I do probably lean a little more toward Rested Gal's efficacy ideas.

I suspect that "suboptimal" therapy, that still manages to suffice as "viable" therapy just may serve simple common-denominator etiologies well enough in most cases. I don't think any of the APAP algorithms are intentionally tailored to specific etiologic subpopulations, Chuck. Rather, I think each manufacturer simply developed their own unique/patentable auto-titrating treatment platforms. But more specifically, that each treatment platform under development was found to viably serve a reasonable majority of the patients tested---each platform inadvertently leaving significant minority percentages outside the margins of efficacy.

And Chuck, your own A10 pressure-based treatment results were definitely anomalous in my opinion, which is exactly what drove me into your summertime thread with great interest in the first place.

I love this thread and I apologize to any who are bored by it.

[GoofyUT]

SWS-
I completely agree with you. I too, believe that the various manufacturers developed their algorithms to treat a modal group in the population of SDB suffers. But, I believe that this population is multi-modal, and that one algorithm's shape better accomodates one mode than another, and it is worthwhile and essential to find the algorithm that best accomodates each individual's mode. I believe that as the science matures, we'll come to understand better the indications that suggest membership in a particular mide and therefore, which algorithm works best for that individual. And, I believe that we'll see more algorithms developed (such as ResMed's ADAPT SV) to better accomodate the new modes that are being discovered.

BTW, I am talking about optimal treatment. I don't believe that viable treatment is acceptable, desirable or ethical. Not when optimal care is within one's grasp and the current state-of-the-art.

_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): resmed

[Goofproof]

After page 2 of this thread, I put on my mask and turn the Remstar Auto on, I don't want to take a chance of being accidently unprotected, while reading this thread.

I side with Rested Girl, APAP's in general, if set correctly, provide good treatment for the majority of users. Some out there have complex issues that APAP's aren't 100% good at treating, but generally they work pretty good, and the cases that don't respond need better solutions.

At a AHI of 0.49, I have found my solution, for those that haven't keep looking. Jim

[Wulfman]

After page 2 of this thread, I put on my mask and turn the Remstar Auto on, I don't want to take a chance of being accidently unprotected, while reading this thread.

I side with Rested Girl, APAP's in general, if set correctly, provide good treatment for the majority of users. Some out there have complex issues that APAP's aren't 100% good at treating, but generally they work pretty good, and the cases that don't respond need better solutions.

At a AHI of 0.49, I have found my solution, for those that haven't keep looking. Jim

And, I'm here to present the opposing view.

I side with......ME. CPAP's in general, if set correctly, provide good treatment for the majority of users. Some out there have complex issues that CPAPs aren't 100% good at treating, but in general, they work pretty good, and the cases that don't respond need better solutions.

At an AHI of 0.6 (for the last 7 days), I have found my solution, for those that haven't....keep looking.

Edit: As of this AM 01/19, my AHI for the last 7 days is 0.5
Edit: As of this AM 01/20, my AHI for the last 7 days is 0.4

Den (ho, hum......going to bed now)

But, you DO need the software to tweak your therapy!!!

[-SWS]

BTW, I am talking about optimal treatment. I don't believe that viable treatment is acceptable, desirable or ethical.

Well, of course, clinical definition for all of these are presently a big challenge in light of that scientific maturation cycle you pointed out earlier.

But what I earlier termed as viable, perhaps could have better been termed as some "reasonable range" of optimal---rather than a discrete pinnacle that may be all too clinically rare. But, just who among us is receiving optimal versus viable APAP treatment is anyone's guess at this point in sleep science.

I am amazed at just how many people here such as yourself tweak until they reach optimal, versus what likely happens much more often in the real world: non-compliance. That's another comparative efficacy number I really wish we had data on. I am convinced the compliance rate is higher here than out in the real world---because of the vast information shared, not to mention the intangible aspects of peer support. Here I'm enjoying peer support at 10:45 PM. Couldn't do that in the real world. Goodnight!

[dsm]

It was a good thread while it lasted

D

[Goofproof]

The advantage I find of APAP, is more options, somewhat easy of use, and lower overall treatment pressure.

The best gain is being able to track what is going on, and I had that under control with CPAP, and the Remstar Pro2 before APAP, in fact, for a while I backtracked in treatment, with the APAP. The more options you have, the harder you make it for yourself to find the answers. It's easy to make wrong conclusions, when changing variables in our treatment, you have to step back and see the bigger picture. Jim

[rested gal]

I side with......ME. CPAP's in general, if set correctly, provide good treatment for the majority of users. Some out there have complex issues that CPAPs aren't 100% good at treating, but in general, they work pretty good, and the cases that don't respond need better solutions.

LOL, Den...yup, regular cpap does probably provide perfectly good treatment for the majority. Would for me.

It's easy to make wrong conclusions, when changing variables in our treatment, you have to step back and see the bigger picture. Jim

You're right, Jim. I've sure reached plenty of wrong conclusions in my time...still do! Thanks to the message boards, I've gotten lots of help and guidance getting my treatment going right -- and as comfortably as possible.

[drbandage]

This is not my area of expertise, but I thought the following document was helpful in understanding what is considered to be standard of care in APAP, at least by the American Academy of Sleep Medicine. FWIW.

http://www.aasmnet.org/PDF/autotitratingreview.pdf

<return to lurk mode>

[rested gal]

Thanks for the link, drB. Very interesting reading.

[StillAnotherGuest]

Actually there was another APAP algorithm shootout in the same issue of the same journal, and the editorial was also on these two articles.

I would try to summarize the editorial, but not the second shootout since the latter has funded by a company related to Weinmann (manufacturer of SOMNOplus masks and SOMNOsmart APAPs).

No, wait a minute, it's the "Measure, Check and Control" Group in Germany. That sounds like a pretty good independent testing outfit to me.

Measure, Check & Control GmbH& Co.

OK, maybe not.

Well, for starters, in the model set up in the bench study by the Barcelona group, assessment of snoring was included, and they also looked at prolonged flow limitation with leaks, obstructive apnea with leaks, and created a closed-loop patient simulation, generating a typical patient response to the application of increasing pressure (during which only 3 machines were able to succeed in inducing normalized breathing).

Hmm, one of them was the SOMNOsmart 2....

...some other interesting results from that bench study concerned the machines employing forced oscillation technique (FOT) as a means to accurately discern central events and respond accordingly...

Well, SOMNOsmart 2 uses FOT.

By process of elimination, after the shootout the only one left standing is...

Ahh, WTH, it's all a conspiracy anyway.
SAG

[GoofyUT]

[quote="drbandage"]This is not my area of expertise, but I thought the following document was helpful in understanding what is considered to be standard of care in APAP, at least by the American Academy of Sleep Medicine. FWIW.

http://www.aasmnet.org/PDF/autotitratingreview.pdf

<return to lurk mode>

[StillAnotherGuest]

Course, on the other hand, in order to get someone to do a large scale study on humans using the different APAPs, I mean, y'gotta eat, so who's gonna cough up the dough to take say, 6 different machines, x-hundred patients, and do multiple night PSG (a single night won't do it, you really need a mean over several nights)? The time factor alone, each "volunteer" patient needs to spend 18 nights (or maybe 21 if you want to establish a baseline) in this project. So if we got 2100 test periods per x-hundred patients, even if we run 2 patients per tech, and depending on the salary structure of the area where you do this thing, you get up to 300,000G's in acquisition costs alone real quick. Add in the professional component (Dr. ABSM-guy, what do you charge for a month of your time?), administrative costs (oh yeah, administrative costs)...

...so again, who's gonna cough up the dough? "Sponsored by a grant from the Acme CPAP Company." There ain't a lot of other motivated groups out there.

Ooh, maybe we can get Consumer Reports. Right after they're done with the infant car seat thing.

Fun Things to Know About Forced Oscillation Technique (FOT)

(FOT-- that still sounds like a potty-mouth word!)

You can end up with a lower pressure:

AutoSet vs. Somnosmart

The Autoset titration pressure (P95) was on average significantly higher than the Somnosmart titration pressure (9.9 ± 2.6 cm H2O vs 7.0 ± 2.5 cm H2O, respectively; p = 0.005). The P50 of the Somnosmart was on average 2.4 ± 1.5 cm H2O lower than the P50 of the Autoset. Moreover, the P50 of the Somnosmart (4.5 ± 0.7 cm H2O) was quite close to the lower pressure limit of the device. Figure 1 shows the Autoset recommended pressure (P95) plotted against the Somnosmart recommended pressure. It can be seen that 12 of 15 patients had higher Autoset than Somnosmart recommended pressures (p = 0.009). Inspection of a Bland and Altman plot (Fig 2 ) displays considerable lack of agreement between the Autoset and the Somnosmart P95s. The bias was calculated at 3.0 cm H2O.

So we're talking about 3.0 cmH2O less. That's a lot.

It could very well be due to FOT (snicker)(sorry, can't help myself):

Effects of High-Frequency Oscillating Pressures on Upper Airway Muscles in Humans

In summary, we have shown that when the upper airway is briefly subjected to a pressure wave of 30 Hz with an amplitude of 4 cmH,O, there is an increase in the activity of some muscles of the upper airway. This occurred in normal subjects and in patients with a range of obstructive sleep apnea. In the latter, the response of the upper airway muscles can be sufficient to open the obstructed upper airway. The occurrence of similar responses in the sternomastoid and diaphragm suggests that a number of receptors are activated by the stimulus. It is possible that these responses could be utilized in developing new treatments for sleep apnea.

And what is an extremely interesting tidbit:

Although it is clear that the stimulus we used is an artificial one, it does mimic in part the high-frequency ressure oscillations that occur in snoring. We suggest that one of the reasons that a snorer can resist complete upper airway obstruction, despite the generation of suction pressures as high as -80 to -100 cmH,O in the upper airway, is that the pressure oscillations and tissue vibration trigger reflex activation of the genioglossus and other upper airway muscles. It is possible that a reduction or loss of sensitivity of such a reflex might be a mechanism by which snoring evolves into sleep apnea.

Now THAT may certainly give some thought about having surgery to correct snoring!
SAG

[SamCurt]

What I can just say is, if Uncle Sam thinks it's big enough problem, NIH and other grants would prove big enough to acquire all CPAP producers in the world, let alone doing bigger investigations.

[-SWS]

One of my all-time favorite threads for sure! I love the points SAG brought out in his previous post, and I always immensely enjoy his humorous style of delivery. I'll be vacationing out-of-the-country in a week, and preoccupied before then with my own client-based work. I hope this wonderful thread doesn't go away anytime soon! As it turns out I have some more thoughts that I would like to contribute to this thread. So if this thread does happen to fade away, I'll resurrect it in a few weeks.

But speaking of wonderful threads, I would like to move a copy of SamCurt's quote below into drbandage's very important thread that is currently underway:

What I can just say is, if Uncle Sam thinks it's big enough problem, NIH and other grants would prove big enough to acquire all CPAP producers in the world, let alone doing bigger investigations.

The extremely important thread:
viewtopic.php?t=16617&postdays=0&postorder=asc&start=0[/quote]