Question on Pressure - Updated Info.

Hey SWS,

Save some for me

Now where did you find those self filling beer glasses I'll take a dozen thanks

DSM

-SWS wrote: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.

Newcomer here but I am afraid that composition is not a strong point of mine so I won't try to come up with a general statement. I will comment on my thoughts as I have read this thread from the onset and struggled with the technical jargon.

When I first saw Doric's initial comment I thought "whoa, this is not good" for only a few seconds then common sense took over because I know that there are many people using the ResMed products with pressures above 10 and doing quite well on them. I could see where someone that is completely new to the whole CPAP thing might be alarmed at statement #1 by itself, but quite honestly, if I had been that novice I likely wouldn't have understood the implications of the 10 cm limit (in its abbreviated form which might alarm someone) either.

It is enough for me to simply add a because........ to statement #1. Because Resmed concentrates on preventing apneas instead of simply responding to active apnea events with a pressure increase. For me as a newbie, that is enough. ResMed's choice to address events that occur at pressures greater than 10 cm with the prevention approach is simply another intricate form of treatment.

It seems like every manufacturer of CPAPS wants to have a unique feature to set itself apart from the others. As a newbie I have no need to dwell on line by line differences in each machine. Way to confusing. The ultimate goal is a reduction of whatever apnea events are occurring. Different companies seem to take different routes to the ultimate goal. I would suspect that in most cases any of these routes would be sufficient for the majority of sleep apnea patients. There may be a few that need one route over another for optimal results but that is the way things go in the medical community because we can have unique needs.
Brenda

-SWS wrote:...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.

Pugsy wrote:When I first saw Doric's initial comment I thought "whoa, this is not good" for only a few seconds then common sense took over because I know that there are many people using the ResMed products with pressures above 10 and doing quite well on them. I could see where someone that is completely new to the whole CPAP thing might be alarmed at statement #1 by itself, but quite honestly, if I had been that novice I likely wouldn't have understood the implications of the 10 cm limit (in its abbreviated form which might alarm someone) either.

Good point.

This newbie will offer:

1. IF you have a valid NPSG;

2. AND you have a valid PAP Titration (the data is accurate, not necessarily that "ideal pressure" is achieved);

3. THEN data will be available that will allow one to accurately select an xPAP machine to suit their needs (and BTW, reread Den's point-- if you are stable on CPAP, then switching to a Turbo Dial Wingin' APAP may get you what you deserve).

4. BUT if you don't have valid a NPSG and PAP Titration;

5. AND decide to self-treat with an APAP using wide-open algorithm;

6. THEN chances are there's going to be an awful lot of "trial and error" before you get where you're going (assuming you get there at all) using A10.

As a frin'stance, let's say one has severe OSA that needs a treatment pressure of 15 cmH2O to address obstructive apneas. If you're using A10, why would you set low baseline to anything less than 15 cmH2O? And if there is a good reason, like "Well, my NREM and non-supine AIs are pretty good, so I don't need or want that much pressure during those times", then your choices are:

1. Don't sleep on your back;

2. Don't go into REM;

3. Don't use A10.

Using the above example, if we KNOW that all the OAs are effectively treated on 15 cmH2O, if a CA does show up (like some post-arousal thing), then A10 will do what it's supposed to do, namely, ignore it.

Muffy

I am positional and suffer from severe allergies. I was titrated 16/14 by the tech to deal with an AHI of 114.7, obstructive events. Doc changed that to 16/12. I use an autobilevel with A10. I run it 8 to 16 with a PS of 4. Many nights my 95 centiles are below 13/9. Some nights I hit 15/11 for my 95 centiles, though. Some nights my pressure line stays flat, other nights it dances, but my AI stays below one and my machine-estimated AHI is always below 10, usually below 5. I might do OK rigging something to stay off my back and using plain bilevel, but right now the auto seems to be doing its thing for me even when I end up on my back in REM. I would love to get a week of PSGs on each autobilevel to see which algorithm was really best for me as an individual. But my anecdotal guesstimate is that A10 seems to be working well enough for now for this hoser.

jnk wrote:I am positional and suffer from severe allergies. I was titrated 16/14 by the tech to deal with an AHI of 114.7, obstructive events. Doc changed that to 16/12. I use an autobilevel with A10. I run it 8 to 16 with a PS of 4. Many nights my 95 centiles are below 13/9. Some nights I hit 15/11 for my 95 centiles, though. Some nights my pressure line stays flat, other nights it dances, but my AI stays below one and my machine-estimated AHI is always below 10, usually below 5. I might do OK rigging something to stay off my back and using plain bilevel, but right now the auto seems to be doing its thing for me even when I end up on my back in REM. I would love to get a week of PSGs on each autobilevel to see which algorithm was really best for me as an individual. But my anecdotal guesstimate is that A10 seems to be working well enough for now for this hoser.

Aaamen !

DSM

jnk wrote:I am positional and suffer from severe allergies. I was titrated 16/14 by the tech to deal with an AHI of 114.7, obstructive events. Doc changed that to 16/12. I use an autobilevel with A10. I run it 8 to 16 with a PS of 4. Many nights my 95 centiles are below 13/9. Some nights I hit 15/11 for my 95 centiles, though. Some nights my pressure line stays flat, other nights it dances, but my AI stays below one and my machine-estimated AHI is always below 10, usually below 5. I might do OK rigging something to stay off my back and using plain bilevel, but right now the auto seems to be doing its thing for me even when I end up on my back in REM. I would love to get a week of PSGs on each autobilevel to see which algorithm was really best for me as an individual. But my anecdotal guesstimate is that A10 seems to be working well enough for now for this hoser.

Jeff, the part that is working perfectly fine for you is the Autoset aglorithm. As you point out, you have hardly any apneas at your higher than 10 pressures. Therefore, the A10 algorithm isnt' even engaged in your case. A10 is just the part of the Autoset algorithm it that keeps if from responding to frank apneas -- when they appear at a pressure above 10. A10 seems clearly irrelevant for this hoser, since you have other events letting the Autoset algorithm drive your pressure up and down, as necessary.

Resmed about the Autoset

Breath-by-Breath Monitoring and Flow-Time Curve Analysis

AutoSet devices monitor breathing on a breath-by-breath basis and deliver only the pressure that patients need--when they need it.
AutoSet devices actually act preemptively by monitoring the patient's inspiratory flow-time curve. A flattening of the inspiratory flow-time curve typically precedes an upper airway obstruction, which will cause an apnea, hypopnea, or snoring.
By monitoring and responding to the flow-time curve, AutoSet devices reduce the number of respiratory events and arousals, enabling better sleep quality.

Simply put, JNK, you are not an example of the breathing pattern on which the Autoset algorithm fails because of its A10 part.
You are an example of the majority of cased in which the Autoset algorithm succeeds because it can do the pre-empting it was meant to do. A10 is not bothering your therapy at all, since the Autoset algorithm manages to pre-empt your apneas very very well. This is true of the majority of people.


O.

All I know is that I had an AHI of 114.7 in my diagnostic, it took 16/14 to address my obstructive events in my titration, and I am being successfully treated (as far as I can tell) with a ResMed autobilevel, with whatever algorithm(s) is/are hiding inside there by whatever name(s).

For all I know, though, the Respironics autobilevel would be just as successful or even more successful in treating me. I will likely never know, though, unless Respironics wants to send me one of their machines for free and pay for a week of NPSGs for me to do a comparison to see which machine best fits my needs.

I would love to read all examples documenting instances in which a patient failed to get good treatment with one company's auto and then got great treatment with another company's auto. In my opinon, until those cases are documented, analyzed, and standardized, I see no reason to tout the effectiveness of one company's autos over the effectiveness of another company's autos whenever people come to this forum looking to buy one.

But, hey, that's just me.

jnk wrote:All I know is that I had an AHI of 114.7 in my diagnostic, it took 16/14 to address my obstructive events in my titration, and I am being successfully treated (as far as I can tell) with a ResMed autobilevel, with whatever algorithm(s) is/are hiding inside there by whatever name(s).

For all I know, though, the Respironics autobilevel would be just as successful or even more successful in treating me. I will likely never know, though, unless Respironics wants to send me one of their machines for free and pay for a week of NPSGs for me to do a comparison to see which machine best fits my needs.

I would love to read all examples documenting instances in which a patient failed to get good treatment with one company's auto and then got great treatment with another company's auto. In my opinon, until those cases are documented, analyzed, and standardized, I see no reason to tout the effectiveness of one company's autos over the effectiveness of another company's autos whenever people come to this forum looking to buy one.

But, hey, that's just me.

I can't point to the examples (although I have a few names in my head), but I have read posts where someone switched to a different brand/model of machine and reported "feeling better" or "better therapy" (and whatever goes with that). Doesn't even have to be the two "R" companies, either.....there are other brands/models that work better for some people.

Who would you propose doing the "standardizing"? Most users and manufacturers have their own preferences.....may be a little hard to quantify.

As I mentioned before, my feelings about "Autos" (in general) is slightly myopic , but I believe that users (new or otherwise) need to be informed that there ARE differences in the way the different brands/models work before they go diving into that pool.


Den

Wulfman wrote: . . . I have read posts where someone switched to a different brand/model of machine and reported "feeling better" or "better therapy" (and whatever goes with that). . . .

It is difficult for me to form impressions of overall effectiveness from anecdotal subjective accounts or to formulate recommendations that I would consider useful to the average first-time auto buyer. But, then again, I have friends that switched from Toyota to Honda because they feel they get a better ride. But that may be just because they are comparing their 1990 Corolla to a 2009 Accord, so that may be throwing off their assessment of the real reasons for their personal preference of brands.

Wulfman wrote:Doesn't even have to be the two "R" companies, either.....there are other brands/models that work better for some people.

In my case I needed (OK, I admit it, "wanted") an autobilevel, not just an auto, so that narrowed my choices a bit.

Wulfman wrote:Who would you propose doing the "standardizing"? Most users and manufacturers have their own preferences.....may be a little hard to quantify.

And that is my point. We as posters on this board similarly may need to be careful about making assumptions about the effectiveness of machines based on our own preferences that some take to be standard. Our personal attempts to quanify may be little more than expressions of our own prejudices and assumptions. If we don't like scientists doing that, we shouldn't either, in my opinion. Manufacturers have biases, but so do users, exactly as you said. So if the scientists doing the studies are expected to make disclosures, we should be quick to make sure the information we pass on is not based on conclusions we have reached based on imperfect understandings of algorithms that may, or may not, be as effective, or less effective, for any individual asking about autos. If someone would like information about algorithms, great. There are people here who understand them. And a person experiencing obstructive apneas when his pressure is above 10 cm may be better treated by a ResMed and treated worse by a Respironics, if that person, like most, has standard precursor events. Or it may be the opposite for him. It is an unknown, depending on the nature of that person's precursor events. To imply otherwise would be misleading based on a misunderstanding of a small part of the treatment picture, imo.

Quantifying and standardizing is, as you say, tricky business. The question asked affects the answer "found." And I'm not sure the industry has neutral parties to look to for that kind of testing, since it takes funds to find answers, and the answers would be of more use to the manufacturers than to the public, in all likelihood. I am just saying that either company could easily find the model nonstandard patient who responds best to one company's approach and point to that, so individual cases prove nothing without defining which edges of which bell curve should be included. In a perfect world, all companies would make information available that would allow docs to know which machines match up best for which patients. That kind of protected information is not available for financial reasons. So I understand this board wanting to give out information on algorithms. I just say that if we expect the professionals to be careful, so should we be. Otherwise would be a double-standard, in a sense, in my view.

Wulfman wrote: believe that users (new or otherwise) need to be informed that there ARE differences in the way the different brands/models work before they go diving into that pool.

I agree with you 100% there, Den. I think any time a person asks about autos, I would want to mention my impression of the limitations of autos. I might even point to the A10 algorithm as an example of how autos do not prevent all apneas from occurring. But I would be careful not to give the impression that ResMed is less effective in preventing apneas when they occur at pressures above 10 cm, since I believe that impression would be an inaccurate understanding of what autos attempt to do and why.

Only my opinion, and I'm wrong a lot.

jeff

jeff-- maybe you are wrong a lot! Most of us are!!!

In this case, I think you are so RIGHT!!

Although it's a little OT, I just had a thought about technical phrasing when I read Mars' comment about the word "frank" and how a mere mortal like myself might not understand what that meant as it relates to OA. (I only learned it by Searching here). I was a medical office manager and worked for this one Dr who always forgot to give instructions in layman's terms to our patients and as an example would tell them to take this or that medicine "bid"(2x daily). Because they were feeling too ill or just intimidated by the "white coat", they never questioned him but would always have to come into my office and timidly ask what bid meant. It's over-simplified I know, but I'm sure there's a message in there somewhere relating to this very interesting thread.

Doric,

I think what you are saying is very important. Doing medical support work, I was always told to use language that an eigth grade student could understand. Sometimes when we are so caught up in the logic and jargon associated with a particular illness, we forget new people don't have that knowledge. SWS has fully acknowledged this as an issue. Plus, there are people who will NEVER be interested in the details of how it all works, they just want the bottom line. Sometimes the newbies get blown out of the water with all the technical info.

I would say, consider that you are explaining this to a child. Make it as easy to understand as possible. Then there can be second and third line info, for those who want more technical data.

DoriC wrote:Although it's a little OT, I just had a thought about technical phrasing when I read Mars' comment about the word "frank" and how a mere mortal like myself might not understand what that meant as it relates to OA. (I only learned it by Searching here). I was a medical office manager and worked for this one Dr who always forgot to give instructions in layman's terms to our patients and as an example would tell them to take this or that medicine "bid"(2x daily). Because they were feeling too ill or just intimidated by the "white coat", they never questioned him but would always have to come into my office and timidly ask what bid meant. It's over-simplified I know, but I'm sure there's a message in there somewhere relating to this very interesting thread.

That's a good point.

I will try to state my personal position in English.

I believe that the purpose of an automatic positive-airway-pressure machine (an "auto") is to prevent as many abnormal breaths and breathing stoppages (apneas) as it can by reacting, as comfortably for the patient as it can, to changes in breathing that may indicate an upcoming problem so that it can raise pressure.

Different brands of autos monitor differently and make decisions differently, but all autos can treat obstructive apnea effectively in most people, it seems, and especially so when the machine is set up with a mimimum pressure that is close to what a patient needs to prevent breathing stoppages.

Some machines attempt to figure out when the brain was responsible for a breathing stoppage, and some machines don't attempt to do that. Some machines lower pressure a little and raise pressure a little at regular intervals in order to test whether changing pressure makes things better or worse, some machines don't do that. Some machines allow for customization of how it reacts, some machines don't. One brand of machine may be better for a particular patient than another brand of machine, but the manufacturers don't release enough information about how their machines work for doctors or DMEs to be easily able to match patients who have unique problems to the machine that might have the best chance of being most effective for that special case.

The changes in pressure that occur with an an auto may disturb the quality of sleep for some for a while. Some never get used to pressure changes at all and end up doing better using a machine that is not an auto. Others eventually get used to the pressure changes, especially if the minimum is set high enough that the pressure changes aren't as sudden or drastic.

ResMed believes that most stoppages that occur when the machine pressure is already above 10 cm H2O of pressure are likely caused by the brain, not an obstruction, so ResMed chooses not to factor in those stoppages to the machine's decision-making process as to what the pressure should be at the moment. Respironics machines similarly ignore any stoppage that is not followed by another stoppage, at any pressure. Those are not bugs, they are truly features. They are different approaches to treating sleep disordered breathing. Both approaches can work for most.

Some, however, have taken ResMed's statements about its approach and misunderstood it and attempted to make the case that anyone who has information indicating he may need a pressure higher than 10 cm to treat him is not a good fit for that brand. That is a gross misunderstanding that does not take into account what autos are for and how they do what they do. I find it interesting that those same people do not, for some reason, similarly misunderstand the Respironics approach. I think that is because one approach makes sense to them personally, and the other approach does not. Therefore, whenever someone asks about autos, some say "if you have apneas that require more than 10 cm of pressure to prevent, don't buy a ResMed." That is misguided at best, malicious at times, silly on many levels. I agree ResMeds may not work for everyone. But other brands don't work for everyone either, and no one attempts to explain that to first-time auto buyers, that I have read anyway. It is easier to make a misstatement about ResMed's approach than it is to make a misstatement about other brands, so ResMed gets punished for having revealed a part of its approach that it is particularly proud of. That likely convinces other brands to hush up information about their approach in order to keep message boards from twisting anything.

NO auto attempts to react to every apnea. ALL autos have complicated ways of trying to prevent apneas.

In my case, I needed more than 10 cm of pressure to prevent apneas when I was titrated. My ResMed is preventing apneas in my case. That doesn't prove I no longer need more than 10 cm to prevent apneas. It proves my ResMed is raising my pressure above 10 cm in order to prevent apneas, which is, after all, what an auto is supposed to do, regardless of what events it is monitoring to choose what pressure it thinks I need at any given moment to prevent apneas. It would be circular reasoning to claim I am not benefitting from ResMed's approach because I am not having events, when the whole point is to prevent events.

Bottom line:

Did it take more than 10 cm of pressure to prevent apneas when you were titrated? Don't worry, a ResMed is as likely to prevent those as any other brand, unless you are some rare exception, because it will see the indications that an obstructive apnea is looming and it will raise the pressure above 10 cm to prevent the apnea. Or at least, it is designed to do that and will try to do it to the best of its ability. It seems to do that for me. Your mileage may vary. Some apneas will still get through, though, just as with any other brand of auto. Only an official test at a sleep lab would be able to properly measure how YOU react to each brand's machines to indicate if another brand would allow more, or fewer, events in your particular case, or would disturb you sleep more, or less.

My mind could always change on those conclusions of mine above, though. I have only used ResMed machines, so I have no way of knowing if I would feel I was getting better sleep using another brand. If I could trade in my ResMed for another brand for a few months in order to find out, I would do it in a heartbeat, though, because I am curious that way by nature.

jeff

ps- Is that any better, guys? At least a little?

jnk, I would like to add to your astute observations. When I was trying to decide what machine to buy as a backup (that might turn into my main machine), I found it a daunting task to make a really good decision. There is very little objective information out there and a good portion of what is available requires a lot of researching or explanation to get any value out of it (like the whole Resmed 10 cm thing). There are varying degrees of relevant subjective information available. I did my best to get all I reasonably could, but when it came time to decide I realized I didn't have enough of the right information. No matter what, short of trying every machine for extended periods with accurate oxygen tracking and many sleep studies, I would be guessing at which machine was right for me therapeutically. How long do you have to try before you know if it is bad nights vs. the wrong machine (or mask, or pressure, or what ever)? Of course, that begs the questions: Is lower AHIs the goal? More restorative sleep? “Less oxygen desat? Would the difference in quantifiable therapeutic results be enough to make a significant difference in how I felt? Would it be enough to overcome an economic "value proposition" difference? How much would I trade in therapy to get quieter performance or some special new feature?

I did as much research as I could. I asked in this forum for help (I asked very imprecisely). I went to my doc, to manufacturer web sites, and to online vendors for customer feedback. None of these sources had complete information and of course accuracy, impartiality, and applicability to me were in question. My doctor could tell me about my sleep study and what was okay or risky for me in general terms, but he certainly isn’t up on all the machines available in the marketplace (he really only knows much about Resmed and Respironics – and thinks both would have been okay for me).

The Intellipap probably had the most subjective reviews recently, heck they even won the challenge – but a pretty good percentage of reviewers chose the Respironics. Not one of those reviews told me conclusively what would be right for me. But the sheer number of reviews that were available without strong negatives certainly factored into my decision, maybe just as a way to ward off buyers remorse.

In short, when I was done gathering information a made a somewhat informed (somewhat wag) decision and hope it was an okay one. Knowingly. What else could I do? I wish I could have pawned off responsibility to someone else and hold them accountable, but that doesn’t happen.

So I did my homework, got all the information I could, and it was still a roll of the dice.

A note about the information and even the misinformation available on this sight: All of it, including the back and forth discourses, has been valuable to me. Even the Resmed over 10 cm thing led me to learn and get half an inch closer to making a decision instead of a blind stab in the dark.

DoriC wrote:Although it's a little OT, I just had a thought about technical phrasing when I read Mars' comment about the word "frank" and how a mere mortal like myself might not understand what that meant as it relates to OA. (I only learned it by Searching here). I was a medical office manager and worked for this one Dr who always forgot to give instructions in layman's terms to our patients and as an example would tell them to take this or that medicine "bid"(2x daily). Because they were feeling too ill or just intimidated by the "white coat", they never questioned him but would always have to come into my office and timidly ask what bid meant. It's over-simplified I know, but I'm sure there's a message in there somewhere relating to this very interesting thread.

riverdreamer wrote:Doric,

I think what you are saying is very important. Doing medical support work, I was always told to use language that an eigth grade student could understand. Sometimes when we are so caught up in the logic and jargon associated with a particular illness, we forget new people don't have that knowledge. SWS has fully acknowledged this as an issue. Plus, there are people who will NEVER be interested in the details of how it all works, they just want the bottom line. Sometimes the newbies get blown out of the water with all the technical info.

I would say, consider that you are explaining this to a child. Make it as easy to understand as possible. Then there can be second and third line info, for those who want more technical data.

I think these are very good points by DoriC and riverdreamer.

I will say that the newcomer threads I usually get involved in are the ones where problems don't seem to be getting resolved after pages and pages of the usual support. I usually limit myself to those newcomer threads because I am not as adept at describing things in simple terms to newcomers as so many of our wonderful experts are. Quite often I will intentionally use terms that I think those newcomers should research. One distinct advantage of our message-board venue is that our words stay static on the page---unlike the doctor's fleeting "bid" comment, that may have sent a few puzzled patients in search of their medications on eBay.

By contrast, the words we place on these pages can be referred to later. They can be reconsidered and even researched. I personally did not like the apnea message boards many years ago, when there were far fewer advanced concepts discussed, far fewer advanced papers linked, far less understanding in the patient population, and far fewer difficult problems resolved via highly technical message board discussions. By contrast, these days we have some wonderfully advanced posters who regularly share advanced topics with each other, toward that common goal of always learning to help others more efficiently.

We clearly need to have both beginners' discussions and advanced-topic information sharing. Not that we ever should... but if we were to leave all discussions to common-denominator language and common-denominator concept levels, then we would be back to the old days when patients on the message boards knew comparatively little about all the nuances and complexities of their apnea and treatment. Now days our intermediate-level posters seem to know far more than most of our advanced posters seemed to know seven or eight years ago.

My gratitude to the many contributors on this message board who are better than I am at conveying wonderfully basic explanations to newcomers!