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Wow! Am loving this thread! If you're interested in the techie side of things, here is a link to the Pdf's of Respironics Patents (thanks to Derek).

Respironics APAP Patent Application (49 pages/3 Mbytes)

Respironics Apnea/Hypopnea Detection Patent Application (14 pages/1Mbyte)

Perry wrote:

Jerry Ask:

But, assuming the machine is 'reading' me, am I likely to notice a difference in the way I feel going from an average AHI of 2.0 to !.0? Just depends, doesn't it on how well the machine is 'reading' me. But, practically, what is the advantage of reducing the disturbances by one per hour. Some of the forum members are reporting untreated AHI's of 30 or even 40 per hour. Am I 'splitting hairs'?

Jerry: At that level you are splitting hairs. Those are phenominal numbers.

Most sleep labs will not prescribe PAP treatment at all for a real "sleep lab AHI" below 5.

Everyone has some events each night. The "apneas" that you machine may be reading might just be sleep transition events that a sleep lab would not count (when transitioning from awake to sleep it is not uncommon for a person to have an stoppage of breathing similar to an "apnea" - and the normal person does this transition several times a night. The sleep lab can see that your brain is in transition and does not count these events at all - your APAP cannot see that your brain is in transition - and counts and even potentially responds to the event).

There was some research done at the University of Wisconsin - Madison that did indicate that long term heart damage could be caused by as low of "sleep lab" AHI's as 4. I do not know if this has actually affected the clinical treatment of OSA yet - I do know that other sites were attempting to duplicate the studies a couple of years ago.

If it helps for comparison purposes: I average an AHI from my APAP of 4 to 8 each night. However, the Hypopnea detection is set at 35% flow for 8 seconds and the Apnea detection is set at 10% flow for 10 seconds (I am using a machine that allows a person to change these settings - It is no longer available, and I am hoping that it's successor kept the user definable events section).

Perry

Very helpful, Perry. Sounds like the machine reports may exaggerate the number of apnea and hypopnea events as compared to a sleep lab study?

My sleep lab resulted in an AHI of 9.5. If I am averaging under 2 at 8 cm with practically no snores, it seems that I am at an effective therapy level. Thanks for sharing your results. If you are satisfied with your therapy, then that is reassuring for me with my results.

BTW, I see you joined this forum this month, but you obviously have been involved in PAP for a long time. Did you just find the forum or have you posted under another name, previously? Anyway, you have a lot to contribute and I'm glad you are participating.

Jerry

Jerry, you must have missed Perry's introductory post:

Any oldtime posters from other forums remember: Perry

Jerry, you know how bad news gets reported and good news is seldom noticed? I think most of us who get intrigued enough about these machines to read about how they work do tend to zero in on the interesting differences.

I love reading about this stuff, even though I'm not technically inclined enough to understand most of the "inner workings".

However, I do believe that ANY properly setup autopap will work well for MOST people who have OSA. The few people who need one autopap rather than another (or no autopap at all) are...well...few and far between, imho. If a person has a problem with one machine or another, or even with all autopaps, there's plenty of time to look at what the incompatibility problem might be. But as Perry said, there's not much way of knowing that ahead of time. It really does take just trying it out.

Just keep remembering, when talking about machine incompatibilities, we're talking about with only a few people. MOST autopaps can deliver excellent treatment to MOST people. And those "Most" can use ANY autopap for equally effective treatment. People who have underlying breathing disorders like asthma might want to choose the only autopap that can give relief of exhalation when running in autopap mode (Respironics REMstar Auto with C-Flex) but otherwise, ANY modern autopap will most likely suit MOST people.

I wouldn't be discouraged by the fact that the only way you can know if a particular brand of autopap will work well for you is by trying it. Nor by the fact that it might take some tweaking to get it going "right" for you.

What's the worst that can happen? You have a machine that cost only a couple of hundred extra dollars compared to the cost of a data-yielding straight cpap machine. Besides, the autopap can always be run in straight cpap mode if it turns out that's what works best for a person....in the FEW cases of the FEW people that autopap doesn't gee and haw well with them.

Which "unknown" would you rather face? Wondering if a single pressure really was right for you all night long when you have only a straight cpap machine to use? Or wondering if you might be one of the FEW that don't do well on "this autopap vs that autopap vs autopap at all?" Autopap users can always set their machines for straight cpap if they want to or need to. But you can't go auto with a straight CPAP machine.

If I were interested in getting an autopap, I'd simply pick the one that has features I want (size? do I want or need exhalation relief? how does it download? what software do I prefer? etc.) Chances are very, very good that no matter which autopap a person chooses, it's quite capable of giving them good treatment and will work very well with them.

Rested Gal Says:


People who have underlying breathing disorders like asthma might want to choose the only autopap that can give relief of exhalation when running in autopap mode (Respironics REMstar Auto with C-Flex) but otherwise, ANY modern autopap will most likely suit MOST people.

Sorry RG. I have to disagree with you on this.

The problem with asthma is that lung capacity is reduced in such a way that a persons inhale breathing curve is affected. Fact is - that it often looks like a "Flow Limitation" or in certain extreme cases like a "Hyponea" (some asthma can come on suddenly - also note that developing asthma typically shows up in the middle of the night to early morning while a certain body chemical is low). Thus, many APAPs will falsely over-respond when faced with someone who's asthma is not under control. Other machines may count them as some form of mouth leakage events (exhale puffs for the AutoAdjust LT) and stop the automatic algorithm as PAP does not work when people start loosing air from their mouth with a nasal mask.

I have personally experienced both reactions by different machines.

I also find it instructive that if you read a full study on any of the machines (not the summary results commonly available) that you will notice that the Mfr's always eliminate people with asthma from the studies on efficacy of APAPs (at least up to 2 years ago).

Thus, the asthma needs to be under control. It really does not matter if the exhale energy is reduced as some of the current machines have. The problem is allowing the machine to properly read you.

By the way - a tidbit of PAP history. Respironics did not invent the concept of automatically varying the fan so that inhale and exhale was easy (The C-Flex concept). This was first introduced as a software upgrade to the AutoAdjust LT in mid product stream. People who already owned one and the software package could download a program from a website to a floppy disc (creating a boot disc) that allowed you to rewrite the actual software inside the AutoAjust LT with this and other upgrades. This had no effect on how the machine handles asthma (personal experience - and this is my base machine - the one that worked best for me from all the machines available several years ago. It is also the APAP I started with in 1999 - it just took me a year to learn how to set it up).

Concerning the ratios of people with problems with different machines. I agree with the basic message - that Most people can use any of the modern APAPs. However, I do think you underestimate the number of people who would do best with one specific machine.

With one specific exception - all the machines currently on the market that I am aware of were basically in existence during the summer of 2003 and I discussed with the Mfr's the details of how they were going to work. In most cases they were just minor tweaks on previous machines. I had tested a RemStar Auto (the newest machine on the market). Now I need to verify exactly what the Mfrs have done and play with the software (and get some patient files) before I post my summary of how they work and problems you should watch for (and I may well have the information here in some boxes for most of the machines); but, I doubt that much has changed in the percentages. The Mfr's were fully aware that there machines did not work for all.

If you take my previous listed stages of treatment (see page 1 of this thread):

Walking Dead
Basic Treatment
Advanced Treatment
Mental Zest

I agree that any APAP will get virtually anyone to the Basic Treatment Stage.

My experience working with people previously who were trying to make their machines work - and who tried different machines indicates that roughly 90% of people could get to Advanced Treatment with any machine. That leaves about 10% who needed a different machine in order for them to be able to live a reasonably productive life.

The numbers for "Mental Zest" are an unknown - but clearly lower than the numbers who get to Advanced treatment. One of the problems here is that many times there are other medical issues that have to be resolved to get to Mental Zest, not to mention proper nutrition and at least some exercise (many times OSA is just be one of several problems). This is why it took me years. I had the APAP set right within a year (after learning a lot about how it and I worked). Resolving the other problems took several years (low blood sugar, food sensitivities).

However, a gut feel based on the small numbers I know who made it and the ones who didn't - would indicate that perhaps as many as 25% of APAP users might need a specific APAP to really get back to the stage where they really have zing again.

But, your point is well taken. People should initially get a machine based on the other factors, and not worry about the "What if" and just deal with it if it happens. I will note that there are a few conditions that if known would direct them to or from certain machines (for example: no use getting a machine that depends heavily on a snore precursor if the person has had UPPP and no longer snores - especially relevant if someone is trying to save money and gets offered a used Virtuoso).

Perry

"Guested" again. The login must time out (it takes me a while to write these things).

The above post is mine.

Perry

Perry there is another group besides asthmatics. Anyone that has any other medical problem that can affect respiratory effort is also in the group that can "fool" an auto. Severe gerd causing respiratory events will do it, and definitely vocal cord dysfunction.

That said, the "average", run of the mill, OSA patient will probably benefit from APAP. But as in masks, APAP is not always a one size fits all.

And Jerry, your comment about the machine over reporting events. Yes this CAN happen. Remember, when you had your sleep study, you were connected by multiple sensors. APAPS are pretty smart, but they are relying on only a couple of sensors and software to determine events. Derek's snore index testing a while back proved that the Remstar Auto can be fooled into thinking you are snoring by manipulation of the hose. Because you are using limited sensor data combined with software, a single night's worth of data should ALWAYS be taken with a grain of salt.

We are often lulled into a sense of accuracy by the colored charts and reports, but the numbers behind them are only as good as the method of collecting the data.

Perry wrote:However, a gut feel based on the small numbers I know who made it and the ones who didn't - would indicate that perhaps as many as 25% of APAP users might need a specific APAP to really get back to the stage where they really have zing again.

My gut feeling, based on the small numbers I know, would indicate that more like 2% of APAP users might benefit from using one specific APAP machine over another to deal with their particular breathing patterns as best interpreted by the algorithms of a given manufacturer. Of course, we need to be sure to emphasize the APAP can be used for titration and evaluation purposes and then simply switched to CPAP-mode for nightly use, should the individual so desire. (One caveat: we aren't doctors and anyone can offer up their "gut feelings" so take it with a grain of salt.)

Perry wrote:I will note that there are a few conditions that if known would direct them to or from certain machines (for example: no use getting a machine that depends heavily on a snore precursor if the person has had UPPP and no longer snores - especially relevant if someone is trying to save money and gets offered a used Virtuoso).

I think we should temper this statement by cautioning people that UPPP surgery does not necessarily eliminate snoring, and even if it initially does, research has shown in 50% of those cases the snoring returns, so it might still be a good idea for a person who has undergone UPPP to use a machine such as you have described that "depends heavily on a snore precursor." In fact, I would even go so far as to suggest a person who has undergone UPPP surgery would benefit from having such a machine to track the declining efficacy of the surgery as the snore detection would indicate.

Whoops, "guested" again.

That was me.

I wrote in response to Perry:

BTW, I see you joined this forum this month, but you obviously have been involved in PAP for a long time. Did you just find the forum or have you posted under another name, previously? Anyway, you have a lot to contribute and I'm glad you are participating.

neversleeps wrote:Jerry, you must have missed Perry's introductory post:

Any oldtime posters from other forums remember: Perry

Neversleeps, I did miss it. It explains Perry's background. Give me credit for recognizing an expert, however.

I've learned a lot about APAP's in this thread. The thread just sort of slipped into the APAP discussion based on input from Perry and I inadvertently encouraged it when I said to Ric,

Ric, I'm pondering your chart. You have an APAP, right? Doesn't it eliminate all apneas/hypopneas if the set pressure range is broad enough? To answer my own question: apparently not, as there are AhI's recorded for each pressure 6-11. Does this mean that the machine doesn't respond adequately to eliminate the disturbances? I'm obviously confused.

That was a very uneducated question. I know better now based on Ric's answer and the other input to this thread.

Well, I'd like to give you some more charts. I know I said I wouldn't and these are only for one night at 10 cm, the highest I have ever used on my straight CPAP REMstar Pro II with C-flex, but Wulfman encouraged me to try a higher pressure and I tried 10 cm: [Charts from My Encore, except as noted]



Just look! AHI of 0.4!!!!



Can you believe, only 4 hypopneas and 5 snores all night!! And, 9.4 hours of usage. Do you think I'm getting enough sleep? I should have chosen 'sleepyhead' for my username.

One thing, however. My wife woke me for the first time in over a month of CPAP to tell me that the mask was leaking (Swift nasal pillow). She said I can hear a rush of air. She thought it was coming from my mouth, but that will usually wake me, or I think it will. I think it was probably from around the pillows due to movement.

From Encore Pro, does this leak information mean anything to you?


Do you think the leaks could affect A/H detection? Might they not be as good as reported?

Finally, the Snore Index vs. Pressure plot:


Isn't that a beautiful plot!

Jerry

PS: RG, if you want to get rid of the red 'x' where your avatar used to be, delete it in your Preferences by clicking on the 'Delete avatar' box.

Anonymous wrote:Thus, the asthma needs to be under control. It really does not matter if the exhale energy is reduced as some of the current machines have. The problem is allowing the machine to properly read you.

Perry, maybe it doesn't really matter to YOU if the exhale energy is reduced on your auto machine but it DOES matter for me. I have not had any problem allowing the machine to properly read me. With my asthma I can inhale a lot better when I have been able to exhale completely and comfortably before I take my next breath. Without the help of cflex I wouldn't be able to tolerate the pressure working against me when I exhale. This asthmatic finds the Remstar Auto with cflex to be a godsend. I'm sorry when you tried it you found it didn't work for you.

Jerry69 wrote:...Wulfman encouraged me to try a higher pressure and I tried 10 cm.

Isn't that a beautiful plot!

You betcha!!!!!!

Den

You ready for this Jerry?

There was a study a while back that wanted to find out if any pressure was better than no titrated pressure.

Here

The study was of an open, randomized, parallel design. Ninety-one subjects with obstructive sleep apnea syndrome were randomized to either arbitrary-pressure CPAP based on body mass index before treatment polysomnography or to CPAP at settings determined by polysomnography. Both interventions resulted in similar improvements in clinical outcomes as determined by Epworth Sleepiness Score, Short Form-36 Quality of Life questionnaire, objective compliance, and subjective attitudes to treatment.

So, how much difference can a couple of cm's difference make? Only slightly better sleep efficiency. But this was only shown through PSG. Not through the limited tool of AHI.

The gist of this? Don't let the numbers determine how you feel. Let YOU determine how you feel.

Jerry, your average leak rate (33.79) for that night is fine!

Looking good!!

One thing, however. My wife woke me for the first time in over a month of CPAP to tell me that the mask was leaking (Swift nasal pillow). She said I can hear a rush of air. She thought it was coming from my mouth, but that will usually wake me, or I think it will. I think it was probably from around the pillows due to movement.

Without tape, I'm the biggest mouth leaker that's ever been... never woke me up.

Mikesus wrote:You ready for this Jerry?

There was a study a while back that wanted to find out if any pressure was better than no titrated pressure.

Here

The study was of an open, randomized, parallel design. Ninety-one subjects with obstructive sleep apnea syndrome were randomized to either arbitrary-pressure CPAP based on body mass index before treatment polysomnography or to CPAP at settings determined by polysomnography. Both interventions resulted in similar improvements in clinical outcomes as determined by Epworth Sleepiness Score, Short Form-36 Quality of Life questionnaire, objective compliance, and subjective attitudes to treatment.

So, how much difference can a couple of cm's difference make? Only slightly better sleep efficiency. But this was only shown through PSG. Not through the limited tool of AHI.

The gist of this? Don't let the numbers determine how you feel. Let YOU determine how you feel.

Mikesus, I follow your gist. The titration put me at 6 cm. I put me at 10 cm. The machine report is better, but do I feel better? Not really, but I never felt bad. Just a little sleepy and requiring [or doing naps]. But, never the 'Walking Dead' that Perry defines.

My developing philosophy: CPAP can't hurt me but potentially can help me...like vitamins. I've got the equipment, so I'll use it. I don't know if I will ever realize improvement because it looks as if any changes are going to be slow to develop. But, I don't want any newbie to misinterpret this. Some of you are walking dead and for you PAP is not an option, it is a life or death matter.

Jerry