Resmed vs. Respironics - Help

[NightHawkeye]

I'm referring to the first setup screen for APAP (after you press the APAP button, and it fades away), where you have 3 scales: Max pressure, Initial prressure, and Min. pressure. Initial pressure is the one I'm talking about.

Yes, no need to clarify. I understood that perfectly, Ozij. I simply latched onto the wrong terminology by mistake due to the fact that the same pressure Icon is used in the manual for both CPAP pressure and Initial pressure. (Honest, I thought I was making things clearer at the time. )

What I did last night was to increase my Initial pressure to 7.5 cm (confirmed in the "Settings" screen in the software data), and I'm certainly no worse this morning for having done that. Data for the night shows some of the better results I've seen recently. Only four apneas and far fewer than normal hypopneas. I still spent about half the night at 4 cm pressure (doesn't bother me a bit) with another hour and a half mostly plateaued between 9 cm and 10 cm. The rest of the data consisted of short segments around 7 cm to 8 cm.

Of course, it's just one night's data, and with about an hour's less sleep than usual for me. Interestingly, I don't even have a hint of aerophagia this morning. Not sure what that means, but I'd be happy for that to continue.

Perhaps last night's results provide a hint of better therapy for me, as was your intent in bringing it to my attention. If better therapy results, then you will have my undying gratitude, Ozij.

Regards,
Bill

[NightHawkeye]

3) Might this hypothetical problem be alleviated with a supplemental dental device?

Did I mention I just got a dental device? (I honestly don't remember posting that.) Only had it a few days. It's actually reasonably comfortable. My primary reasoning had to do with my own TMJ issues and wanting to give an FFM a try. So far, I only spent one miserable night with the FFM though. Fortunately, I got sidetracked with Ozij's finding about the PB algorithm. Also, it's worth noting that for some reason I woke up without the dental device in my mouth this morning but have no recollection of taking it out. I do remember putting it in. Strange.

Anyway, in regards to the airway, I can't tell that the dental device has resulted in any improvements in either reduced pressure or number of events, but it's comfortable enough that I intend to continue using it. Actually, without having used the dental device all night I had TMJ pain this morning, something which surprisingly (to me) I did not experience any of the nights I used the dental device. Again, strange. Although I don't experience TMJ pain often, it's not uncommon either. Perhaps, for me, there's another benefit to the dental device.

Regards,
Bill

[-SWS]

3) Might this hypothetical problem be alleviated with a supplemental dental device?

Did I mention I just got a dental device? (I honestly don't remember posting that.) Only had it a few days. It's actually reasonably comfortable. My primary reasoning had to do with my own TMJ issues and wanting to give an FFM a try. So far, I only spent one miserable night with the FFM though. Fortunately, I got sidetracked with Ozij's finding about the PB algorithm. Also, it's worth noting that for some reason I woke up without the dental device in my mouth this morning but have no recollection of taking it out. I do remember putting it in. Strange.

Anyway, in regards to the airway, I can't tell that the dental device has resulted in any improvements in either reduced pressure or number of events, but it's comfortable enough that I intend to continue using it. Actually, without having used the dental device all night I had TMJ pain this morning, something which surprisingly (to me) I did not experience any of the nights I used the dental device. Again, strange. Although I don't experience TMJ pain often, it's not uncommon either. Perhaps, for me, there's another benefit to the dental device.

Regards,
Bill

Also wondering about the various tongue-restraining devices that seem to suit or fail some folks better than others.

Forgetting about APAP's potential weaknesses for just a moment, I'm wondering to what extent this hypothetical problem may play a role regarding excessive residual AI for optimally titrated CPAP patients (with that optimal simply being: "best highly imperfect AI results achieved").

I suspect physiology can yield more than just a few reasons to return excessive residual AI scores. Also wondering how hyoid bone placement or size characteristics may contribute to this as a hypothetical problem for perhaps some/many cases of excessive residual AI, even on fixed-pressure CPAP.

Anyway, the exploration of this hypothetical case might even resume with: "Hey! Let's assume this does happen in at least some cases..." Boy am I hoping conversation continues along this line. But I also need a little break because of a little sleep deprivation on my part. There's no dishonor in being a conversational slacker at times!

Genuinely hope that line of inquiry continues...

[dsm]

More comments on using pressure to clear in-flight OSA obstructions.


CAs and using pressure increases
--------------------------------------
1) While Apaps use caution & very slow pressure increases (to avoid either trying to treat CAs with pressure or induce them) timed Bilevels are designed to tackle CAs. This is a given fact. And, they do use rapid pressure increases (ipap) combined with rapid pressure drops (epap) within one breathing cycle as their mechanism for dealing with CAs - point being that pressure as therapy is used by the right device at the right time.

OSAs and using pressure increases to clear occlusions
-------------------------------------------------------------
2) Again Apaps show great caution in increasing pressure with an OSA event be it a partial occlusion (hypop) or a full occlusion (block).

But anyone on a Bilevel knows that these machines merrily carry on fliping between epap and ipap during an OSA block & I have charts that show that even at 15 CMS they don't clear OSA blocks that are underway (my CPAP titration was originally for 13 CMS then later 12 CMS so 15 CMS should have been able to clear anything I ever encountered if pressure can clear a block).

http://www.internetage.com/cpapdata/menu_0804.html

The above chart was during a period of monitoring & experimenting with settings to see what effect they might have. From the chart shown, If I reduce the ipap CMS, the number of AIs drops, they will also drop if I increase epap (which is more or less to be expected).

Point here is that Apaps really don't try to clear in-flight OSA occlusions & the above chart sees pretty good proof that even a machine that can rapidly raise the pressure (in this case by a whopping 8 CMS) wasn't clearing the multitude of OSAs once they had started.

Note this machine was in Spontaneous mode - the BPM was quite normal (max 19 av 14.5) & in S mode the machine doesn't go to IPAP until the sleeper actually starts to breath in. The tidal volume was what I consider good.

Any comments



DSM

#2 clarified intent & meanings
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CPAPopedia Keywords Contained In This Post (Click For Definition): Titration, CPAP, APAP

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CPAPopedia Keywords Contained In This Post (Click For Definition): Titration, CPAP, APAP

[Velbor]

I will not pretend to understand all of what you have been talking about. I understand enough to enjoy and appreciate the information. It does bother me, though, that being (I trust) of reasonable intelligence and possessing (I trust) a greater-than-average scientific knowledge, that I can't always figure out WHAT you are talking about.

There seem to be three trains of thought going around and around:
(1) discussion of the pathophysiology of apneas (and sometimes hypopneas),
(2) discussion of the behavior of AutoPAP machine algorithms, and
(3) discussion of how topic (2) impacts, or is impacted by, topic (1)

Around and around you go, agreeing with each other, arguing with each other, "insulting" each other, apologizing to each other, being pedantic, and being humble.

Don't get me wrong - I enjoy reading your stuff. Just wish I knew where you all think it's going. I have no objection to collecting random facts with the possibility that they'll be useful and/or meaningful sometime later. But I get the feeling (very possibly mistaken) that individually and/or collectively you believe that you are moving toward some endpoint. My thinking that you think that you have a direction, and my not being able to decipher what it is, may be contributing to my difficulty in following the conversation.

The thread started with a question about ResMed vs. Respironics. I found myself particularly intrigued, for selfish reasons, by one "offhand" comment which had come up earlier:

What about the folks who have persistent apneas which are never resolved by CPAP therapy. I could point to numerous postings to illustrate this. Sure, lots of folks get their AHI's down below 1.0, but just as many have consistently high residual AHI's. If they're not caused by centrals what else could they be caused by? Corks, maybe? Maybe some similar physiological mechanism?

and a more recent comment:

Also wondering about the various tongue-restraining devices that seem to suit or fail some folks better than others. Forgetting about APAP's potential weaknesses for just a moment, I'm wondering to what extent this hypothetical problem may play a role regarding excessive residual AI for optimally titrated CPAP patients (with that optimal simply being: "best highly imperfect AI results achieved"). I suspect physiology can yield more than just a few reasons to return excessive residual AI scores. Also wondering how hyoid bone placement or size characteristics may contribute to this as a hypothetical problem for perhaps some/many cases of excessive residual AI, even on fixed-pressure CPAP. Anyway, the exploration of this hypothetical case might even resume with: "Hey! Let's assume this does happen in at least some cases..." Boy am I hoping conversation continues along this line. ....

Now, time for my confession. I seem to fit into this category. All of the posts claiming that PAP "success" is getting an AHI under 5.0, and suggesting that those of us who don't accomplish this are necessarily "not doing something right", engenders feelings of inferiority. Well, posh!! I renounce such notions!! I've been at this game long enough to have "tweaked" all reasonable possibilities, while my average AHI hangs around 10. (Yes, I use a ResMed auto, so the machine figure is allegedly "higher" than reality. One night's use of a Respironics auto gave a 7.5 value. And yes, leaks are well controlled. And no, having had multiple PSG's, never even one Central Apnea has been identified.)

So, masters of (1), (2) and (3), work me into your theorizing. I do much better with PAP (even if ResMed!) than without it. I do somewhat better with straight CPAP than with AutoPAP, but not really enough to make a significant difference. But I do best using a dental (mandibular advancement) appliance. Why?? Corks??? Eggs?? What parts of your conversation are useful to me at a practical level? As NightHawkeye indicated, my situation is not unique. Where does my sort of experience fit into your deliberations? Please, do continue along this line.

In any case, you have my gratitude for providing fascinating, even if difficult (and, .... perhaps .... sometimes .... obscure) reading.

[dsm]

<snip>

Don't get me wrong - I enjoy reading your stuff. Just wish I knew where you all think it's going. I have no objection to collecting random facts with the possibility that they'll be useful and/or meaningful sometime later. But I get the feeling (very possibly mistaken) that individually and/or collectively you believe that you are moving toward some endpoint. My thinking that you think that you have a direction, and my not being able to decipher what it is, may be contributing to my difficulty in following the conversation.

<snip>

Velbor,

There has been a significant amount of learning going on here by the bulk of us - old timers & newcomers alike.

I for one am working on a quiz that poses many questions based on typical CPAP terminology and situations & purpose of particular machine usage.

The quiz will be in sections (beginers level to advanced levels ) and is intended to help people understand what they do and don't know & to guide those interested to learning more.

I have done a 1st cut at the quiz & am now refining & adding new sections. Much of the answers will be based on points covered here.

I'll eventually post the quiz on my own CPAP website

DSM

#2

PS this has been one of the more polite threads we have managed to sustain and that has IMHO open the floodgates quite wide in accepting each others points of view - to me that is a major breakthrough in itself.

SWS does use very technical medical terminology & that poses some challenges in following some of his threads but in its own way, this provides an intellectual challenge that certainly pushes me to deeper understanding of the point at hand.

It is also clear to me that there are different perceptions among us & while some of us are very detail minded others are more concerned with impressions of xPAP therapy & less on specific nuts & bolts detail. That in itself reflects the wide interests and capacities of us participants. It can cause communication blocks but again I believe this particular thread has been one of the best for bringing the diversity of our views together.

DSM
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[-SWS]

Don't get me wrong - I enjoy reading your stuff. Just wish I knew where you all think it's going. I have no objection to collecting random facts with the possibility that they'll be useful and/or meaningful sometime later. But I get the feeling (very possibly mistaken) that individually and/or collectively you believe that you are moving toward some endpoint. My thinking that you think that you have a direction, and my not being able to decipher what it is, may be contributing to my difficulty in following the conversation.

Greetings, Velbor. Think of conversation at a cocktail party: highly unstructured, overly animated at times, and plenty diverse. By the way, will you have yours shaken or stirred?

I'll rejoin this thread in a few winks. In the meantime you're guaranteed to get some interesting opinions. At least I hope you do.

[rested gal]

Very insightful post, Velbor. Yeah, I think some people want concrete answers, definitions, measurements, etc. (where bottom line is, "it depends".. lol! ) while others are more willing to look at many "it depends" scenarios.

A big cocktail party, for sure, as -SWS said...with people talking, listening, discounting some things, having a lightbulb go on, drifting away from one conversation to take up another... the usual.

I found myself particularly intrigued, for selfish reasons, by one "offhand" comment which had come up earlier:

What about the folks who have persistent apneas which are never resolved by CPAP therapy. I could point to numerous postings to illustrate this. Sure, lots of folks get their AHI's down below 1.0, but just as many have consistently high residual AHI's. If they're not caused by centrals what else could they be caused by? Corks, maybe? Maybe some similar physiological mechanism?

Often (not always...just "often") it's a simple matter of their not having their pressure set high enough, imho. Particularly the minimum pressure with an autopap, or the EPAP setting in a bilevel. It can also be a matter of "it depends." Depends on knowing what needs treating in the first place -- simple OSA? OSA along with centrals? CompSA? OSA complicated by other health conditions...GERD, for example? Vocal Cord Dysfunction? And even at the treatment end of things -- mouth breathing with a non-FF mask?

Some, like you, Velbor, have indeed tweaked all reasonable possibilities, but I think most fall into the "haven't optimized" everything they can yet category. Especially mask issues, other health issues, pressure setting issues...or maybe haven't yet really identified accurately exactly "what needs treating" in regard to their particular sleep disordered breathing.

I have no objection to collecting random facts with the possibility that they'll be useful and/or meaningful sometime later.

Me too. Fascinating nuggets turn up when least expected sometimes.

Personally, I think one of the most interesting things that has come out of this meandering thread so far has been ozij's information about the way the PB 420E autopap operates around its unique "initial pressure" setting, if that setting is "set" where it was designed to be used.

Don't get me wrong - I enjoy reading your stuff.

Same here.

[Snoredog]

[quote="-SWS"]On the contrary Bill. Please let me explain.

The perceived cumbersome part of our conversation right now goes on my part. I'm having some trigeminal neuralgia pain just "nipping" away throughout much of my discussions (hopeful surgery in early May! Woohoo!). I'm fairly certain that TN pain is making both me and my analytic approach downright insufferable for some people (sorry!!!).

When I work theories all by myself, I at least attempt to build just as many competing theories as I can. Then I very comfortably proceed to analytically kick the living daylights out of just as much as I possibly can---both as I go along and when I reach some tentatively conclusive endpoints.. So I'll analytically flip and flop with myself just like a carp---only much quicker than my bud, Snoredog, could ever humorously document for my own benefit of laughter.

But I'm very comfortable when I approach problems in my preferred manner this way. It's when I attempt to employ that approach with others where I get in trouble because of my lacking social acumen. Not yours, my friend. So the reason I wanted to step out of only that part of the discussion is because I think I may be hindering it. And I don't want it hindered.

Everyone agrees that at least after occlusion everything that you and Doug say is happening. Ozij even succinctly points out that before administering CPR we need to literally pull the tongue up and out of the way.

I think what you guys are saying (despite my poor attempts at searching for any possible refinements along the way) is that once that occlusion occurs, it can render CPAP momentarily useless. I'm inclined to agree on that point.

So here are only a few points I was hoping people might have gotten around to at least speculating about:

1) Might this be a rare or prevalent problem regarding excessive residual AI (since residual AI varies widely across the population)?

2) Might this hypothetical problem in relation to CPAP be associated with certain craniofacial characteristics?

3) Might this hypothetical problem be alleviated with a supplemental dental device? etc., etc., etc.

I can't force anyone to further explore this issue. But I was hoping for a rest as I quite enjoyably watched others explore the issue. Bill, don't you dare think I'm scooting around you. Very specifically it's your contrasting views that I appreciate most. Why the hell would -SWS want to have conversations with clones of -SWS? Makes no darn sense to me I tell you!

Kudos to what you guys do with topics and how you do it! Me thinks you'd never guess I'm such a big fan!

[NightHawkeye]

My thinking that you think that you have a direction, and my not being able to decipher what it is, may be contributing to my difficulty in following the conversation.

Rest assured, Velbor, that there is not only direction, but also a very clear goal (however clear or unclear it may be to any of the individual participants here).

... (drumroll, please) ... Comparison of Respironics, ResMed, PB, F&P, & other machines

The thread started with a question about ResMed vs. Respironics.

Appropriate, yes? (But, why has ResMed fallen by the wayside?)

So far, we have covered some important aspects of the Respironics and Puritan-Bennett functionality as revealed by their respective patents.

This frank discussion of basic functionality has been needed here for a long time. I believe that this message board provides sufficient motivation for the topic to continue, perhaps in this thread, certainly in other threads, regardless of how many of the current participants stay in the game. The question of which machine is best (dare I say that?) is not likely to be squelched. The answer, of course, depends on a number of things, some machine related, some dependent upon who's gonna use the machine.

The motivation for the topic to continue appears strong ...

Here are the relevant APAP patents for the various manufacturers (as provided by Respironics in their recent patent 7168429).

5245995 - Sullivan
5259373 - PB
5549106 - PB
5845636 - PB
5458137 - Respironics
6058747 - Respironics
5704345 - ResMed
6029665 - ResMed
6138675 - ResMed

The above are all clearly assigned (I think). Other patents apply as well, although the lineage of their assignments to existing companies is more obscure:

5645053 - Remmers (This is the one I started out with.)
5335654 - Rapoport
5490502 - Rapoport
5535739 - Rapoport
5803066 - Rapoport (This is the one Ozij referenced.)

The game is open to all. Price of admission is digging into patent literature. They're not nearly so difficult to follow as you might think. Just stay away from the CLAIMS section when starting out. (Ozij, to her credit, didn't do that though.) The claims section is legalese, but also where important critical details lurk.

Other data is applicable to the discussion as well, including slick sheets from the manufacturers (although those, as one might suspect, need to be despun).

Hope this helps answer your question, Velbor.

Regards,
Bill (who still questions why, on God's green earth, this discussion is so emotionally laden)

Edit: P.S. http://www.freepatentsonline.com allows free and easy access to the patents. Registration is free. Patents can be viewed online or can be downloaded in PDF format. Simply enter the patent number in the search field. Alternatively, comprehensive searching is also available on-site there.

[Guest]

hi all,

patency, patency, patency!

Mckooi

[ozij]

hi all,

patency, patency, patency!

Mckooi

Patent see, patent see....

Another source is http://www.google.com/patents it gives links to the USPTO.

O.

[StillAnotherGuest]

And without knowing exactly what's in the algorithms (Is what's in these patents actually in the machines?) there's often little chance of matching patients up with the "best" algorithm.

No argument about that. But do look at the FDA quote - PB is pretty clear there about how the auto mode is expected to be used in this machine.

Further, given the timeline of the patent (1996-1998), the algorithm under consideration is undoubtedly the one in the 418P, and that machine was a slug when it came to returning to baseline.

SAG

[Snoredog]

And without knowing exactly what's in the algorithms (Is what's in these patents actually in the machines?) there's often little chance of matching patients up with the "best" algorithm.

No argument about that. But do look at the FDA quote - PB is pretty clear there about how the auto mode is expected to be used in this machine.

Further, given the timeline of the patent (1996-1998), the algorithm under consideration is undoubtedly the one in the 418P, and that machine was a slug when it came to returning to baseline.

SAG

Depends on the FL's seen, turn command on FL1 off by unchecking the box and it is no slug returning to initial pressure baseline, in fact probably the fastest machine out there, can take some of the others 10 or more minutes to do the same.

[ozij]

The FDA document.

Received: May 9,2003

http://www.fda.gov/cdrh/pdf3/k031470.pdf

The GoodKnight 420 Evolution can operate in either Constant or Automatic mode. In Constant mode, the device delivers a constant positive airway pressure to the patient at a fixed level prescribed by the practitioner between 4 and 20 cmHrO. In Automatic mode (APAP mode), the practitioner sets a maximum and minimum pressure range above and below the prescribed reference pressure and between 4 and 20 cmHz0. The pressure is adjusted within this range according to the patient’s respiratory pattern and the type of respiratory events detected. Data concerning the type of events detected, their frequency and duration, etc. is stored in the device data memory and can be accessed by the practitioner through the use of the optional Silverlining'" software. Pressure delivery for
the GoodKnight 420 Evolution is regulated by a pressure sensor which monitors both ambient and output pressure and provides feedback to the control system.