Question on Pressure - Updated Info.

SWS

Maybe I am wrong & maybe I am right, I only ever saw you belatedly correct, often in a obscure wording, the misunderstandings.
There have been many times when some of our regulars, did not correct this glaring misunderstanding but IMHO set out
to reinforce it. So I have often seen it as an act by omission.

I do agree with JNK, you would focus on the technical accuracy of your statements BUT very pointedly skirt the issue that I would
raise that the A10 statement, in isolation, clearly caused misunderstandings to newbies. You always came back and argued that
I was questioning your technical accuracy but would skip around the real issue that the A10 mantra, as it was, caused
misunderstandings to non technical people.

This thread is the 1st time the matter has been taken to some conclusion & only because DoriCs statement was so compelling,
she eradicated all wiggle room.

So on the matter of technical accuracy, to your credit you now have a double statement set that goes a good way to explaining
the A10 point and in terms many can follow. Thanks.

Steve, my perceptions will only change when I see this A10 matter dealt with fairly on a consistent basis. As I have already
said, I doubt it will happen, but lets see.

DSM

[quote="-SWS"

My proposed revision for my own future posts:
1) Resmed will not directly respond to frank apneas above 10 cm,
2) Resmed will effectively treat apneas above 10 cm by preventing them.

Confusing? Clarifying? Misleading? Underhanded wording? Truthful?

Thanks in advance.[/quote]

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Hi -SWS

Sorry to say this -SWS. but by adding the word "frank" without a definition of what you mean by "frank" , you have now gone from clarity to confusion.

Maybe I have got it wrong and your first two sentences were not correct and needed clarification. Fair enough, but I hope you will try again.

cheers

Mars

-SWS wrote:
This is a tough topic apparently filled with faaaaar more social challenge than technical challenge:
1) Resmed will not directly respond to apneas above 10 cm, and
2) Resmed will effectively prevent apneas above 10 cm in most cases.

So what's so technically complex about the above two sentences? :?: I don't plan on changing my views or words about technically-easy sentence one or technically-easy sentence two one iota. So please get over it. Resmed apparently doesn't plan on changing highly basic technical truths either.

Yes, there are yet other posters here who love to cite technically-easy sentence one while omitting technically-easy sentence two. That's not where the technical confusion comes in guys. That's where the social chaos enters the picture. .....

The newcomer-confusion enters the picture only when posters neglect technically-easy sentence two in blue text above. (polite smilies go here)

Agreed, -SWS, you and your two statements are not the problem.
The problem, as I see it, is that YOU are not being quoted, either in full (both statements) or partially (the first only).
Paridoxically, the problem, as I see it, is that it is RESMED that is being quoted:
"The pressure will not rise above 10 cm H2O when an apnea is detected ....."
and it is RESMED which omits your statement #2 (in any useful, accessable way, made in continuity with their equivalent of your statement #1).

It is ResMed itself which has created confusion, not by any inaccuracy, but by inadequate communication. I might also have written, "by inadequate attention to public relations" but I suspect that you would not receive that formulation kindly!

Velbor

Velbor

Resmed did an interview many years ago in which a number of points were made - why 10 CMs ?, what A10 does over 10 CMs & why ?.

The so called Resmed statement 'doesn't respond to apneas' statement was grabbed out of context & in isolation & used because it
created the very effect much of this thread has been dealing with.

I have no doubt they regret that interview (still present on another website) was ever given because they have paid quite a
price for it being used against them.

I can assure you that Resmed do not go around quoting just that portion of the A10 action. Actually Ozij linked us to an
interview with Dr Berthon-Jones where he explained A10 very clearly and in full context. I saved a copy of it somewhere.

I'll dig it out & provide a link. Problem with any detailed article is that only a few of us will read it. Most of us tend
to go for the one liners.

DSM

Here is a link to the interview with Dr Berthon Jones - I am sure we can glean 2 or more factual statements that fairly explain the issue from his interview. He invented & developed the A10 algorithm.

http://www.internetage.ws/cpapdata/resm ... 0906r1.pdf

When Ozij 1st link to this I located a full set of outstanding articles that deal with very current CPAP topics & are great reading but some do get technical. Here is the full set, any of them can be clicked & downloaded as PDF docs.

http://www.internetage.ws/cpapdata/resmedica/

The one at the top of the list (10) is newest & has some interesting comments about CompSA that I think most people can read & understand.


DSM

I've pulled out these pertinent comments & added a brief comment of my own in parenthesis ...

> best approach is to respond very quickly to loud snoring, and then fine tune using flattening
(why the A10 responds quickly when well below 10 CMs)

> actual apnea is pretty rare on AutoSet, because in most cases the responses to snoring and
flattening get the pressure up quickly enough to prevent apneas. (Berthon-Jones explanation of
SWS's line #2)

> when you are on CPAP, this tendency to have what are called central hypopneas - hypopneas
that are nothing to do with the state of the airway - is increased. If you make an automatic CPAP
device that responds to hypopneas, you will put the pressure up to the maximum while the patient
is awake.

> I mentioned before that the higher the pressure, the more central hypopneas you will have.
At a pressure somewhere around 10 cmH2O, the central hypopneas become central apneas.
On the other hand, the vast majority of obstructive apneas are already well controlled by 10 cmH2O,
and we are only fine tuning using snoring and flattening

> So it is a pretty good bet that if the pressure is already above 10 cmH2O, any apneas are most
likely central, and you should leave them alone (except in patients with central apneas due to heart
failure). But if the pressure is below 10 cmH2O, most apneas will be obstructive and you should put the
pressure up. There’s nothing magical about 10 cmH2O, it’s just a good place to put the line in the sand.

> You can’t over-treat obstructive apnea. You really don’t want the patient having unresolved
obstructive apneas. And we want not just to prevent apnea - we also want to keep the airway sufficiently
open for the subject to breathe easily and regularly and stay asleep. But you can use too much pressure.
The higher the pressure, the greater the side effects. Although this has never been proven, it is rather
obvious - no pressure, no side effects! So you want to use the lowest pressure possible while keeping the
airway nicely open.

*******************************************************

These points really cover all Resmed's rationale for A10 & as mentioned we should be able to glean a
few one liners from them.

*******************************************************

Am adding these interesting points as well...

Q> Likewise can a device that responds to hypopnea over-treat it ?
A> The funny thing is that it can both over-treat and under-treat. It will put the pressure up through the
roof in some subjects, who have lots of central hypopneas. And it can completely miss repetitive severe silent
inspiratory flow limitation that is totally disturbing the patient’s sleep without there being any hypopneas. If
this occurs without CPAP, it is called upper airway resistance syndrome. It is just as bad for you as obstructive
sleep apnea. But a CPAP machine that responds only to hypopneas will treat your obstructive sleep apnea, and
give you upper airway resistance syndrome instead.

This paragraph is partly cover up above but is here in its entirety ...

Q> Why is it important for an automatic CPAPdevice to respond to flow limitation, snore and apnea?
A> The characteristic flattening of the flow-time curve caused by flow limitation is the very best signal for
fine-tuning the pressure, once you have eliminated apneas and snoring. But if you are just falling asleep, you
can go very quickly from having a totally open airway to snoring very loudly, in a way that produces somewhat
chaotic or messy flowtime curves, without seeing the characteristic flattening. So the best approach is to
respond very quickly to loud snoring, and then fine tune using flattening. Rarely, you can go straight from awake
and unobstructed to asleep and apneic, and so it can be useful to increase pressure in response to apnea as well.
However, actual apnea is pretty rare on AutoSet, because in most cases the responses to snoring and flattening
get the pressure up quickly enough to prevent apneas.

DSM

dsm wrote: . . . JNK - a question for you
What is the use of a very accurate statement that is couched in terms that few can possibly understand ?. . . .

Accuracy requires context. -SWS has always made the 10-cm-A10 statements in the context in which they are most useful, imo. Part of the context of his statements is the fact is that he is making them. I find -SWS's statements more helpful than ResMed's own statements. Or as Velbor put it so well:

Velbor wrote: . . . It is ResMed itself which has created confusion, not by any inaccuracy, but by inadequate communication. . . .

I understand that you do not like the context in which certain facts are used. I agree that the way certain facts are used by others on this board makes them misleading. But I see no way anyone can blame -SWS for that. In fact, as -SWS just said:

-SWS wrote: . . . I agree that some people are clearly bashing Resmed with highly selective half-truths. . . .

What more should, or could, he say?

Here is a wild opinion of mine for you, DSM: In my opinion, ResMed is darn proud of the very statement that keeps getting used "against" them here. ResMed, I believe, considers the statement that the A10 algorithm doesn't respond to apneas over 10 cm to be a major selling point and something that professionals need to hear. After all, the professionals are ResMed's main customers, not us. Most people take whatever machine is handed them, after all. The people who participate in these boards are the exceptions, not the rule. Individuals buy one machine at a time, but DMEs hand out hundreds and doctors prescribe thousands. That is the audience for the statements ResMed makes about their machines. Doctors often resent manufacturers speaking directly to end users, too, just as they resent drug companies advertising to patients. ResMed is smart enough not to alienate their business buyers who make up the backbone of their profit model.

That is why I am particularly thankful that people like -SWS, SAG, ozij, and rested gal, and a host of others, deal with us nobodies out here trying to make a go at making our therapy work for us. They are making information available to us that is insider information of the most valuable kind, because it is tailored to the user. No one else is in the business of providing that, as far as I can see. I am flattered that people of that caliber are willing to interact with me/us. When they do, I see no reason for us to belittle them for doing so. It is common courtesy not to publicly question their motives or accuse them of having a hidden agenda when there is no evidence of that. -SWS occasionally makes technical comments that are hard to understand. But he does it for a reason, and I have found his statements nothing but helpful, even when I've had to pull out the dictionary to catch the nuances.

mars wrote: . . . by adding the word "frank" without a definition of what you mean by "frank" , you have now gone from clarity to confusion . . .

I believe that the word "frank" is ResMed's wording, as I think ozij mentioned earlier in this thread.

I think it is often difficult to make a technically accurate statement easy to follow. Statements on medical and technical issues generally require compromise between specific, exact wording and broad common wording. Make a statement that is too exact, and you lose the nontechnical reader. Make a statement in common language that is too broad, and the technical-minded cry foul. In my opinion, -SWS walks that fine line admirably time after time. There is no way he could please everyone all the time, and personally I'm happy if he pleases himself while freely sharing the fruits of his experience and research and treating us all with such gentlemanly respect. I think he deserves the same treatment in return, don't you, DSM?

But I feel silly "defending" him. He doesn't need it.

jeff

mars wrote:

-SWS wrote:
My proposed revision for my own future posts:
1) Resmed will not directly respond to frank apneas above 10 cm,
2) Resmed will effectively treat apneas above 10 cm by preventing them.

Confusing? Clarifying? Misleading? Underhanded wording? Truthful?

Thanks in advance.

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Hi -SWS

Sorry to say this -SWS. but by adding the word "frank" without a definition of what you mean by "frank" , you have now gone from clarity to confusion.

Maybe I have got it wrong and your first two sentences were not correct and needed clarification. Fair enough, but I hope you will try again.

cheers

Mars

Got Google? Look it up. There are lots of references to it.

Den

Jeff

I hear your points but just want to add this - I can't see why Resmed would be pleased with that single A10 sentance when people like DoriC read it and then tell their supplier "no I don't want one of them thanks". I understand exactly what DoriC was thinking & it is most likely how I would have though 3 years ago.

Peace

DSM

PS I would add that IMHO the reasons Resmed's sales have rocketed lately is because of the quietness of the blower & the EPR feature. Certainly not because of the A10 one liner.

Wulfman wrote:

mars wrote:

-SWS wrote:

My proposed revision for my own future posts:
1) Resmed will not directly respond to frank apneas above 10 cm,
2) Resmed will effectively treat apneas above 10 cm by preventing them.

Confusing? Clarifying? Misleading? Underhanded wording? Truthful?

Thanks in advance.

---------------------------------------------------------------------------------------------------------------------------------------
Hi -SWS

Sorry to say this -SWS. but by adding the word "frank" without a definition of what you mean by "frank" , you have now gone from clarity to confusion.

Maybe I have got it wrong and your first two sentences were not correct and needed clarification. Fair enough, but I hope you will try again.

cheers

Mars

Got Google? Look it up. There are lots of references to it.

Den

Hi

Thanks for the suggestion.

However the point of clarity in what we say is so that we do not have to keep on checking Google. I may check it out, you may check it out, but others would not. And they would either be confused, or possibly misinformed.

And I guess it does not matter who invented the description "frank", it can still be confusing for newcomers.

Or it could even be - I have obstructive apneas, not frank apneas, never heard of them, so obviously this does not apply to me.

If I have something to say, and you have to Google words I have used, then I am not communicating well. Sometimes this is unavoidable. I think what -SWS is trying to do now is to cover all bases, so that further investigation and confusion is minimised.

Lets all work together on this.

cheers

Mars

dsm wrote: Maybe I am wrong & maybe I am right, I only ever saw you belatedly correct...

"Belatedly correct" people who don't use whatever A10 wording you insist on? That would make it your hot issue, Doug. Not mine.

Strange logic that anyone but Doug and Doug alone should be expected to enforce Doug's own personal A10 topic choices on this message board.

dsm wrote:I have no doubt they regret that interview (still present on another website) was ever given because they have paid quite a
price for it being used against them.

If Resmed so deeply regretted that information, they wouldn't repeatedly print those same words that Velbor just quoted year after year after year. Would they?

Velbor wrote:It is ResMed itself which has created confusion, not by any inaccuracy, but by inadequate communication. I might also have written, "by inadequate attention to public relations" but I suspect that you would not receive that formulation kindly!

I think Resmed's public relations dollars would be better spent trying to reel in Doug's Resmed public relations campaign.

But seriously, I agree with you on that point, Velbor.



_____________________________________________________________________________________________________________________________________

Mar, thanks for that very frank feedback. Pun intended. That input is appreciated in no small way.

I think I like the statements the way I originally had them.

To all of us - slights aside (they have gone both ways) - this thread has been one of the best I have seen in dealing with some warped impressions of Auto algorithms - as in any good discussion the important facts will bubble to the surface if the agitation bringing them to the surface is equal & even.

So I am saying thanks to everyone's POV and am confident a lot of folk will have gleaned a much better understanding of what their Auto is trying to do to & for them.

Now if we can just bottle up some salient one-liners

DSM

mars wrote:Hi

Thanks for the suggestion.

However the point of clarity in what we say is so that we do not have to keep on checking Google. I may check it out, you may check it out, but others would not. And they would either be confused, or possibly misinformed.

And I guess it does not matter who invented the description "frank", it can still be confusing for newcomers.

Or it could even be - I have obstructive apneas, not frank apneas, never heard of them, so obviously this does not apply to me.

If I have something to say, and you have to Google words I have used, then I am not communicating well. Sometimes this is unavoidable. I think what -SWS is trying to do now is to cover all bases, so that further investigation and confusion is minimised.

Lets all work together on this.

cheers

Mars

Try this one (quote from Bill Bolton):

viewtopic.php?f=1&t=38498&p=336931&hilit=frank#p336931


Den

Hi All

Re: Wulfman quote above -

Tried it ! Liked it !

Especially

-------------------------------------------------------------

A Resmed APAP flow generator will certainly respond to apneas arising from precursor hypopneas at over 10cm, but it will very deliberately not respond to "frank" apneas (that is apneas with no precursor events) at over 10cm, to avoid the possibility of triggering central apneas in some users.(Billbolton)

----------------------------------------------------------------

So why don't we all go down to the Forum pub, down a few cold ones, and relax for a while. What Carbonman said on another thread - something like - it is our difficulties with each other that make life challenging and interesting, (not an exact quote) can be applied here.

Still, as I so often hear on TV when one part of the US Government does not like what another part is doing - we are on the same team.

Actually, saying that never seems to make any difference

cheers

Mars

So why don't we all go down to the Forum pub, down a few cold ones...

Cheers, Mars! Don't mind if I do!


Now that I am plastered, I'll share a loose thought: that newcomers, who have read this far, can probably help draft a more suitable statement or two---than long-timers like me who have focused too long on all the details.

If any newcomers care to play <hiccup> this silly drunk man's game, I would encourage you to submit as few or many statements as you like. Summarize any statements in this thread that you happen to like. Or rewrite something brand new. Bring any statements from near or far that you think may do. Perhaps we can make them clear and fair for newcomers--- so that long-timers like me can quote them in the future.

Do that for our next excuse to have a forum group brew! <hiccup>