Question on Pressure - Updated Info.

General Discussion on any topic relating to CPAP and/or Sleep Apnea.
-SWS
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Re: Question on Pressure - Updated Info.

Post by -SWS » Tue May 26, 2009 9:44 pm

Plowboy wrote:Ok, I am going to try this again from a novice point of view. The whole intent, as I understand it, is to "splint" my airway open so I can draw breath and not desaturate, cause a big dump of adrenaline into my system, stress my organs and cause general havoc. That being said, If I set my pressure to a specific level in CPAP mode, all I need worry about is being able to handle the constant pressure from a personal "comfort" level, try and drop my AHI to the lowest possible level (snores, leaks and all rectified for the sake of this argument). Once I am comfortable and acclimate, maybe then begin to play with the settings to achieve a more comfortable experience, learning the technical stuff along the way as it applies to my specific equipment.

I equate this discussion with some of the IT gurus I work with, their preferences have nothing to do with the comparative simple functions I need from a computer, I just need it to open excel, word, etc., etc., and don’t really care about processor type, platform, bios settings, etc. As long as the damn thing performs at the simple level I need to do my job, that’s all I care about

Ditto CPAP therapy, if it keeps me around a little longer and improves my quality of life, I don’t really care at this point to fiddle with the damn thing and confuse as well as discourage my compliance. I think the Dr. and the DME should have set mine to CPAP only right now and we could have got into the technical stuff after I was kind of "dialed in".


Phil
Phil, did you by any chance get a satisfactory pressure value from a sleep study? If so, I'd start off by setting the machine that way. A fixed-pressure CPAP value? Or perhaps even two fixed IPAP and EPAP BiLevel values?

Yes, the idea with CPAP is to stent the airway open---with a worst-apnea-case pressure. The other bells and whistles are intend to offset unintentional side effects, or just the discomfort of pressure, that you may not even experience.
Last edited by -SWS on Tue May 26, 2009 10:05 pm, edited 1 time in total.

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DoriC
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Re: Question on Pressure - Updated Info.

Post by DoriC » Tue May 26, 2009 10:05 pm

-SWS wrote:Doug, if you think DoriC's statement is a slam-dunk in logic, that's fine. I completely disagree with you. Here's the heart of what DoriC said:
DoriC wrote:Very few things made any sense to me at the time but something did jump out at me that I thought I understood perfectly. "Resmeds do not respond to apneas over 10cms".
But her statement contains only one of those two highly basic A10 concepts I have highlighted in blue. It would be beneficial to understand exactly why the other basic A10 concept I have highlighted in blue is missing from that initial perception.

These are the two simple truths that newcomers should be able to easily understand IMHO:
1) Resmed will not directly respond to apneas above 10 cm, and
2) Resmed will effectively prevent apneas above 10 cm in most cases.
Sorry I didn't get back sooner. I think I can safely answer that I truly don't remember reading very much about the #2 statement although I'm sure it was explained many times but may have gone over my head at that confusing time when I knew nothing. I do remember interpreting #2 as responding only to snores(didn't even know what flow limitations were) but not to the dreaded "stop breathing" events. #1 seemed to be such a definitive statement that needed no explanation, while #2 would have required a followup question such as "so how does it prevent apneas above 10cm", when I was not yet ready to join in any discussion.

Den, you got me thinking and now I remember that the machine used during titration looked nothing like the Resmeds I see here for home use, it really looked like a piece of hospital equipment which also scared the daylights out of us. And I can remember the tech telling me that they would keep manually raising the pressure all night ( so no auto there). It's strange that I've seemed to block some of those early scary days out of my memory, all I remember is it wasn't pretty!

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Re: Question on Pressure - Updated Info.

Post by DoriC » Tue May 26, 2009 10:26 pm

SWS, BTW, I think your simple solution to this ongoing confusion is to always use #1 & #2 in any discussion about A10.

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Re: Question on Pressure - Updated Info.

Post by -SWS » Tue May 26, 2009 10:58 pm

DoriC, thanks for that feedback! I just looked at your old posts, and see your husband came full circle, very close to his PSG value of 13 cm fixed pressure. And that 12 or 12.5 cm fixed pressure value Den mentioned seems to be what works best for him now. So here we have a good case study in favor of at least trying what the sleep lab recommends, instead of instantly hopping on the APAP bandwagon per message board fanfare.

And what a fierce political movement APAPs can be on this message board.
Wulfman wrote:As far as DoriC's husband's therapy goes, the vast majority of his apneas were/are "frank"......

Any more questions???

Den
Thanks for the invitation. I'd like to understand that Resmed disaster prediction a little better. If it's nothing more than an intuitive opinion, then it stands just fine for me as precisely that.

But if there are precise factors such as the frank apnea comment above, I wouldn't mind hearing the specifics that roll into that Resmed disaster prediction. Terrible leaks alone are enough IMHO. But they're an APAP disaster prediction---not a Resmed specific disaster prediction. But I'm curious about that generalized frank apnea observation. Again, thanks for that invitation for follow up questions.

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dsm
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Re: Question on Pressure - Updated Info.

Post by dsm » Tue May 26, 2009 11:25 pm

Phil,

Put simply, going onto cpap therapy is something some people have to do (to keep their jobs ) & others go onto, to improve their health & well being.

For years there has been growing concern at the numbers of people on cpap machines who give up. The single biggest cause of abandoning the therapy is related to mask management, that is dealing with the leaks, the discomfort of breathing out against pressure, the claustrophobic effect of sleeping with a mask on, the personal inconvenience. In addition to mask management are other issues such as bloating from ingesting air caused by the cpap therapy (aerophagia), and even issues like the embarrassment some of us used to or may still feel (I sure did but not now).

The problems increase with the pressure applied. As a simple rule of thumb, once a person is given a titration pressure of around 16 and higher, the problems become quite a struggle.

Autos were one line of thinking that the machine could start low & only raise pressure when events are detected. It has had quite mixed results as the best results only seem to occur when the range of pressures is set very close to the titration (i.e. 2 CMs below & say 2 CMs above).

CPAP & Bilevel are the two stalwarts of the therapy.

DSM
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DoriC
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Re: Question on Pressure - Updated Info.

Post by DoriC » Wed May 27, 2009 9:06 am

SWS, thanks for reading my early posts, I can't tell you how many times I was ready to give up especially since it's so difficult being the caretaker and not actually knowing what it feels like. I was urged a few times to put the mask on myself and turn on the cpap but couldn't bring myself to actually do it. I'm such a baby! Nowadays, Mike dons and adjusts the mask himself, adds water to the HH and it is pretty much routine. I have so many heroes on this forum who took me under their wing, too many to list all of them, but Hawthorne at the beginning and Den to this day have our everlasting gratitude.
Thanks for going easy on me on this thread, I think I was in a little over my head!

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is not an act but a habit"-"Aristotle"
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-SWS
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Re: Question on Pressure - Updated Info.

Post by -SWS » Wed May 27, 2009 9:50 am

Well, you did quite well in this thread, DoriC. Thank you for providing all your valuable input!

But most of all, I am so glad you, Hawthorne, and Den got your husband's therapy nicely squared away! Very nice!

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Re: Question on Pressure - Updated Info.

Post by DoriC » Wed May 27, 2009 10:46 am

Well, since I'm always itching to adjust the pressures just to "see",(don't be mad, Den!), you'll be interested to know that I tried a narrow range of 11-13 last night and hubby's AHI was 0.3!

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Re: Question on Pressure - Updated Info.

Post by Wulfman » Wed May 27, 2009 10:56 am

DoriC wrote:Well, since I'm always itching to adjust the pressures just to "see",(don't be mad, Den!), you'll be interested to know that I tried a narrow range of 11-13 last night and hubby's AHI was 0.3!
LOL!
I'm not mad. As long as it's working for Mike, that's what counts.......as long as he's sleeping well, feeling good and his leaks are under control.

Den
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Re: Question on Pressure - Updated Info.

Post by Plowboy » Wed May 27, 2009 12:12 pm

DSM,

Sorry If I came across as a little agitated, I am actually tolerating the therapy quite well, I just wish the actual Dr. I went to was better informed and the RT was also, they seem to take it for granted that a person automatically knows all this stuff and will adapt easily. I am nothing if not persistant and will folow through no matter how uncomfortable but my confidance in the medical community is much lower now than it was before I started on this journey.

I echo many folks on here that appreciate all the advice and direction given by you "long timers".

Many thanks,

Phil

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Re: Question on Pressure - Updated Info.

Post by raylo » Wed May 27, 2009 1:44 pm

Did someone ask for a perspective from a relative newcomer?

I just bought a new machine and decided on an auto adjusting machine. I decided to go the auto route because, in spite of compliance and tolerance, and in spite of 2 incremental raises from my titrated pressure of 8 cm to 9 cm and then 10 cm, I was having what felt like too many bad nights. Often (but not always) they were nights with higher AI or AHIs. I knew/know enough to realize that zero AIs may not be a realistic goal, and that AIs may indicate REM sleep (just like a "regular" person). My doctor even gave me samples of provigil (I have yet to take one).

When deciding on which machine I did question the whole "doesn't respond to apneas above 10cm" thing? But somewhere I realized that it had to be responding to something over 10 cm or what would be the point. I took it upon myself to get clarification in a different thread that I was on the right track. I must admit the idea still lurked around my mind for a bit. I also talked about my machine choices with my doctor (who is not as up to date with what is in the market as we are here) and settings. I was able to talk to him in an informed way because I visit here so often.

I would encourage anyone who has a decent doc who will talk with them to engage them in getting information needed to make a purchase decision. Don't get me wrong, I don't just do what the doctor says without question, but I think he should be involved in my therapy decisions We talked about my present state, my good nights and bad, AIs an AHIs, the fact that Resmeds are said to count more hypopneas. One thing that might be important in deciding which machine/algorithm might be whether or not there were any indications of central apneas in the sleep study.

He didn't think it was absolutely necessary for me to have an auto or any particular brand, but he did agree it was worth doing if I was getting another machine anyway. So I went from 10 cm to 7-14. I had thought that was too wide open, but I am using the full range with most time spent at lower pressures. However, my AI appears to be lower - although that is subject to who is counting, and my AHI is much more stable, regardless of how it is counted.

All in all I'm pretty comfortable with where I am right now, and that is due to the wide range of information available on this site. Including from all the main contributors to this thread. It would seem that your differences are minor compared to the lack of info generally available a dn unexplained statements.

Yes statement 2 needs to be there, but thank goodness for the dialogue that broings stuff like that out.

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Re: Question on Pressure - Updated Info.

Post by jnk » Wed May 27, 2009 3:28 pm

-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.
I'll bite:

Does statement one mean that all other brands do respond to the one lone, sudden, unaccompanied, frank apnea?

Does statement two mean that ResMeds are generally more effective at prevention than other brands?

My point in asking those questions is to illustrate that it is always possible to misunderstand wording, even perfectly truthful and accurate wording like yours. Or ResMed's.

My belief is that whenever any post to a newbie looking to buy a machine points out the limitations of one brand of auto without pointing to the limitations of its competitors, that post can be misleading to the newbie even when it is accurate.

The occasional ResMed mini-bashing by others (even if done in innocence and ignorance) irritates me. But it irritates me even more when someone unfairly accuses you, -SWS, of having had any part in that bashing. I assume DSM is trying to be funny when he accuses you of tricky wording, since anyone who has read this board for any amount of time knows that such accusations are beyond ludicrous. In my opnion, the only ones who mislead are those who repeatedly point out limitations of one brand of auto to newbies looking to buy but never mention the limitations of the other brands.

-SWS, I personally would not want you to ever water down the facts with adopting the wording of any advertisement literature. I like how you have said it in the past and are saying it now just fine, even if some will continue to misunderstand. So please don't let the circumstance that some misuse facts, or misunderstand facts, or make accusations against you for mentioning facts, keep you from the good work you do here. That's all I ask.

Although I am new (10 months), these would be my points about brand algorithms for any newbies looking to buy an auto:

1. No auto is designed to prevent all apneas, but all brands of autos are effective enough for most people.
2. Ignore the posters who try to steer you toward, or away from, a particular brand based on their misunderstanding of the algorithms (despite how clearly and accurately -SWS has repeatedly explained the facts on this board).
3. Whichever brand of auto you get, if you have trouble getting good results with it, try restricting the range based on your data or running it in CPAP mode before spending your money on another brand.


Confusing? Clarifying? Misleading? Underhanded wording? Truthful?

jeff

-SWS
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Re: Question on Pressure - Updated Info.

Post by -SWS » Wed May 27, 2009 3:44 pm

All good points, Jeff. Thanks for adding that.

Thanks DoriC, plowboy, and raylo for your added comments as well.

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Re: Question on Pressure - Updated Info.

Post by dsm » Wed May 27, 2009 4:21 pm

JNK,

I share your admiration for SWS & his regular expounding of accurate detail. I also agree that the two statements that SWS now puts up are a way of describing aspects of the Resmed algorithm.

I admit I was taken aback that DoriCs ipso facto comments, were being questioned while the point she made in support of my case appeared to be being skirted around. What she said got right to the heart of this A10 issue. It was only when others also began to say they had similar reactions that the point appeared to be accepted. My frustration is & has always been how durned blatantly obvious that this all was - we have had this argument for over 2 years that I recall. IMHO Blind freddy could see the issue !. DoriC just happened to nail it dead center and flattened any misinterpretation.

That I believe is a good thing. Do I believe this will raise its ugly head again - yes!, I think it will be raised again & unless you or I or some other person who knows the accurate story steps in, the misconception will be allowed to stand.

DSM

#2

JNK - a question for you
What is the use of a very accurate statement that is couched in terms that few can possibly understand ?.
Is it fair to wonder why any such statement is made in such a way ?
The writer can always step back and say "what I said was 100% right - whether anyone grasped it was not my problem."

Vendors go to a lot of trouble to explain respiratory matters in laymans terms & because this is a laymans forum there
needs to be considerable thought given to clarity in a message. I accept that no one will always get it right.

D
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-SWS
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Re: Question on Pressure - Updated Info.

Post by -SWS » Wed May 27, 2009 5:42 pm

So who is "Blind freddy" and how exactly does he relate to my constantly getting implicated in Resmed bashing by one and only one person on this message board?

And I don't believe I side skirted DoriC's information either. I wasn't involved in her original threads. Rather, I tried to find out exactly why my summarized information in blue statement number two failed to get imparted. That's a statement summarizing A10 information that I have repeatedly mentioned in other threads. And there are plenty of candidate reasons for that information to not have been imparted.

I agree that some people are clearly bashing Resmed with highly selective half-truths. I thought I had clearly acknowledged that in my first of four points at the tail end of this thread: viewtopic.php?f=1&t=42124&st=0&sk=t&sd= ... 45#p371307.

So again, why am I repeatedly getting implicated when I never took part in the original MAP-era Resmed bashing or any other Resmed bashing thereafter? See my comment in the post linked above about totally screwed logic or yet other motives. As a refresher, that was one of my posts about two fiercely opposed half-truth camps around here versus the less convenient but worthwhile full-truth approach.