Thoughts about the future of wide open 4–20 setting/detecting optimal APAP pressure

I must have gotten some things wrong, and I stand corrected.

It’s still a mystery to me why my AirSense 10 gives me a much higher pressure than what is needed in order to treat my apneas and hypopneas if I set the maximum pressure to 20. I wonder if other machines would react in a similar way.

alexander wrote: ↑

Sun Aug 25, 2019 2:14 pm

It’s still a mystery to me why my AirSense 10 gives me a much higher pressure than what is needed in order to treat my apneas and hypopneas if I set the maximum pressure to 20. I wonder if other machines would react in a similar way.

Because it treats more than apneas and hyponeas in auto mode....snores and FLs are actually a much bigger driving force for pressure than people realize and you don't necessarily see evidence of those happening as much as a flagged event can be seen easily.

Pugsy wrote: ↑

Sun Aug 25, 2019 2:24 pm

alexander wrote: ↑

Sun Aug 25, 2019 2:14 pm

It’s still a mystery to me why my AirSense 10 gives me a much higher pressure than what is needed in order to treat my apneas and hypopneas if I set the maximum pressure to 20. I wonder if other machines would react in a similar way.

Because it treats more than apneas and hyponeas in auto mode....snores and FLs are actually a much bigger driving force for pressure than people realize and you don't necessarily see evidence of those happening as much as a flagged event can be seen easily.

What more than apneas and hypopneas does it treat? Would you suggest in most cases then to set the maximum pressure to 20?

alexander wrote: ↑

Sun Aug 25, 2019 2:29 pm

What more than apneas and hypopneas does it treat?

What part of this did you not understand?

Pugsy wrote: ↑

Sun Aug 25, 2019 2:24 pm

Because it treats more than apneas and hyponeas in auto mode....snores and FLs are actually a much bigger driving force for pressure than people realize and you don't necessarily see evidence of those happening as much as a flagged event can be seen easily.

Snores and Flow limitations are considered early warning signs of the airway collapsing or trying to.

alexander wrote: ↑

Sun Aug 25, 2019 2:29 pm

Would you suggest in most cases then to set the maximum pressure to 20?

Yes....that's what I do myself. I let the machine sort it out and I don't worry about it. It won't go anywhere without a good reason.
Now if the going anywhere caused a problem....then I would decide whether or not I wanted to limit where it wanted to go.
Main thing might be aerophagia. If someone had bad aerophagia at say 14 cm...and the machine wanted to go higher I might limit the max to 13 and make a compromise in therapy. It's a case by case basis. No hard fast rules. Depends on how bad the aerophagia might be and what the machine was wanting to go higher to kill.
Since you have never had bad aerophagia...you don't really understand just how ill it can make person. It's a lot more than a little belching and farting. It can be extremely detrimental to a person's sleep and how they feel/function during the day.
It is counter productive to kill everything with more pressure if we sleep like crap and feel like crap by killing everything with more pressure.

I have had really bad aerophagia twice...so I know just how ill it can make a person.

Pugsy wrote: ↑

Sun Aug 25, 2019 2:24 pm

Because it treats more than apneas and hyponeas in auto mode....snores and FLs are actually a much bigger driving force for pressure than people realize and you don't necessarily see evidence of those happening as much as a flagged event can be seen easily.

Sorry, I had some brain fog or something similar, and was a bit unsure how to comprehend. I understand.

Pugsy wrote: ↑

Sun Aug 25, 2019 2:24 pm

Yes....that's what I do myself. I let the machine sort it out and I don't worry about it. It won't go anywhere without a good reason.
Now if the going anywhere caused a problem....then I would decide whether or not I wanted to limit where it wanted to go.
Main thing might be aerophagia. If someone had bad aerophagia at say 14 cm...and the machine wanted to go higher I might limit the max to 13 and make a compromise in therapy. It's a case by case basis. No hard fast rules. Depends on how bad the aerophagia might be and what the machine was wanting to go higher to kill.
Since you have never had bad aerophagia...you don't really understand just how ill it can make person. It's a lot more than a little belching and farting. It can be extremely detrimental to a person's sleep and how they feel/function during the day.
It is counter productive to kill everything with more pressure if we sleep like crap and feel like crap by killing everything with more pressure.

I have had really bad aerophagia twice...so I know just how ill it can make a person.

Thanks for the explanation. I’ll try it out to see if it can work for me.

alexander wrote: ↑

Sun Aug 25, 2019 1:48 pm

palerider, I’m not an expert. I see that people in this thread discuss the machine chasing a variety of events,

People say a lot of completely erroneous things, this is the internet, with just a little bit of effort, you can find that the world is flat, or a donut, or trapezoidal, aliens from other planets walk among us, some are reptilian inside their human suits, and far more "pearls of wisdom".

alexander wrote: ↑

Sun Aug 25, 2019 1:48 pm

and by chasing I assume that they mean that the machine increases pressure when it shouldn’t.

These are simply the statements of people that are ignorant of facts. They may be perfectly fine individuals, but THEY ARE WRONG. Disregard their commentary.

alexander wrote: ↑

Sun Aug 25, 2019 1:48 pm

So my understanding, which might be wrong, is that the current machines do in fact increase pressure in some cases when they should not. Is my understanding correct?

No, your understanding is wrong.
Here's a video explaining the actual real reasons that auto machines increase pressure:
https://www.youtube.com/watch?v=-gie2dhqP2c

alexander wrote: ↑

Sun Aug 25, 2019 1:48 pm

I have little knowledge about pressure increases due to snores (I don’t think I normally snore),

Watch the video, you'll have understanding.

alexander wrote: ↑

Sun Aug 25, 2019 1:48 pm

leaks (I usually don’t have a problem with this),

I already TOLD YOU that the machines DO NOT INCREASE PRESSURE DUE TO LEAKS, in fact, the opposite.

alexander wrote: ↑

Sun Aug 25, 2019 1:48 pm

and aerophagia (I don’t swallow that much air).

That concept is ludicrous, and nobody has said that machines increase pressure due to air swallowing, (and if they did, they are full of crap, and spouting same). ask yourself, how would the machine know you'd swallowed air?

alexander wrote: ↑

Sun Aug 25, 2019 1:48 pm

I was just summing up what was mentioned in this thread.

And has already been refuted.

alexander wrote: ↑

Sun Aug 25, 2019 1:48 pm

What I do have some personal experience with (but admittedly not much knowledge about) is flow limitation. If I set my maximum pressure to 20 then it will probably go to 13. However, most of my apneas and hypopneas are treated around 6.0–7.0. In my case, what I believe happens, is that increased pressure leads to increase flow limitation, which leads to increased pressure. I might of course be wrong, but what I do know is that with my current pressure settings I get restful sleep, and my AHI is usually around 1.

You're *WRONG*. put simply and bluntly, the only reason that your pressure has gone up is *because* of either snores or flow limitations. As I said, you have cause and effect reversed.

There's more to sleep disordered breathing than just apneas and hypopneas, learn that simple concept.

palerider and Pugsy, I’m glad to be wrong, and I have to say that I feel much more alert after a night with maximum pressure set to 20. Here is a screenshot of my night: https://i.imgur.com/pEoWK04.png

So what I’ve learned is that the machine increases pressure for the right reasons, and that SDB is more than apneas and hypopneas. It’s also flow limitation and snoring. And that swallowing air might be a reason for capping the pressure, but that it’s reducing the effect of the therapy.

What bugs me a bit now is that it’s possible to have a really low AHI, and still have disturbed sleep.

alexander wrote: ↑

Sun Aug 25, 2019 11:33 pm

What bugs me a bit now is that it’s possible to have a really low AHI, and still have disturbed sleep.

"bugs you"?

Turn off the calendar, turn off the right panel, bring in the flow limitation graph.

palerider wrote: ↑

Mon Aug 26, 2019 12:03 am

alexander wrote: ↑

Sun Aug 25, 2019 11:33 pm

What bugs me a bit now is that it’s possible to have a really low AHI, and still have disturbed sleep.

"bugs you"?

Possibly not the best choice of words, but English is not my native language.

palerider wrote: ↑

Mon Aug 26, 2019 12:03 am

Turn off the calendar, turn off the right panel, bring in the flow limitation graph.

https://i.imgur.com/DqJBXcG.png

Does it look acceptable?

Pugsy wrote: ↑

Sun Aug 25, 2019 2:41 pm

"...If someone had bad aerophagia at say 14 cm...and the machine wanted to go higher I might limit the max to 13 and make a compromise in therapy. It's a case by case basis. No hard fast rules..."

This is actually the fuzziest part of xPAP therapy.

At the core (talking garden-variety sleep apnea with no other complicating issues), it's really simple: supply enough air pressure to splint the airway open, but not so much that the therapy itself causes issues (waking leaks, aerophagia, etc). So, you want the pressure to be at least "X", and in *some* cases, no more than "Y".

Finding that "Goldilocks" pressure range for a given person is the trial & error part that takes time, patience and ability to read & accurately review your data. It varies person to person. Most all of us have the time & patience. Thank goodness we have this forum with PAP veterans willing to lend their skilled, experienced "eye" to accurately assess the data from time to time.

I had to lower the upper limit on mine as I noticed a pattern of aerophagia above a certain pressure. Over time, my lower limit and upper limit got close enough together that I just changed to CPAP mode, set to the pressure the machine settled on every night. That works for me. It probably won't work for most others. I accept that since my machine no longer auto-adjusts, there will be the occasional night where I may have higher apnea events. But in my particular case, so far that means most nights my AHI is below 1 and about one night out of 10, my AHI may see 3+ -- and I think that depends on what I have for dinner (may or may not be odd - I don't know).

It seems to me, folks get on PAP therapy and their expectations are similar to taking medicine, where you can easily determine their "dosage" is as simple as requiring "X"-mg of medicine per lb of body weight. But it's not that easy. With PAP therapy, I believe it's possible for identical twins to need different machine settings (perhaps slight, but different regardless).

Like Jerry Rosa (Rosa String Works) likes to say about luthiery, "It's simple, but it's complicated". I think that applies to PAP therapy too.

That's my take on it from the peanut gallery with all the other laymen.

-JD

alexander wrote: ↑

Sun Aug 25, 2019 11:33 pm

What bugs me a bit now is that it’s possible to have a really low AHI, and still have disturbed sleep.

There is simply a lot more to good sleep quality than AHI numbers. Accept it and move on. Getting nice low AHI numbers is actually the easy part but it doesn't guarantee anything except a good math score. There are people who don't have enough flagged AHI events to warrant the OSA diagnosis who still have extremely disturbed sleep due to airway issues. It is not all AHI only stuff.

JayDee wrote: ↑

Mon Aug 26, 2019 4:55 am

At the core (talking garden-variety sleep apnea with no other complicating issues), it's really simple: supply enough air pressure to splint the airway open, but not so much that the therapy itself causes issues (waking leaks, aerophagia, etc). So, you want the pressure to be at least "X", and in *some* cases, no more than "Y".

JayDee wrote: ↑

Mon Aug 26, 2019 4:55 am

Finding that "Goldilocks" pressure range for a given person is the trial & error part that takes time, patience and ability to read & accurately review your data. It varies person to person. Most all of us have the time & patience. Thank goodness we have this forum with PAP veterans willing to lend their skilled, experienced "eye" to accurately assess the data from time to time.

JayDee wrote: ↑

Mon Aug 26, 2019 4:55 am

It seems to me, folks get on PAP therapy and their expectations are similar to taking medicine, where you can easily determine their "dosage" is as simple as requiring "X"-mg of medicine per lb of body weight. But it's not that easy. With PAP therapy, I believe it's possible for identical twins to need different machine settings (perhaps slight, but different regardless).

Exactly...that's why so much of this OSA and cpap stuff comes with that big YMMV sticker. It's not cut and dry or simple for a lot of people despite people expecting it to be or wanting it to be. If dealing with OSA or any sleep disordered breathing problem was as easy as just getting a low AHI...that's the easy part but we don't always get there without problems along the way (like the aerophagia stuff) or simply the other stuff that points to sleep disordered breathing that isn't included in the AHI but is still a huge factor in terms of overall sleep quality and without good sleep quality that AHI number is meaningless. I can get a perfect AHI score of 0.0 but that doesn't mean I slept great and if I don't sleep good I already know that I won't feel so good.

People expect to take a pill have the pill fix everything...they expect cpap to do the same thing...but often it just doesn't work out that way either for the pill or the cpap machine. Life would sure be simpler if it did but life is never simple.
Pills have side effects...so does cpap and sometimes the side effects are worse than the original problem. Sometimes we have to decide which problem is the worse problem and accept less than perfect.

alexander wrote: ↑

Mon Aug 26, 2019 12:15 am

palerider wrote: ↑

Mon Aug 26, 2019 12:03 am

alexander wrote: ↑

Sun Aug 25, 2019 11:33 pm

What bugs me a bit now is that it’s possible to have a really low AHI, and still have disturbed sleep.

"bugs you"?

Possibly not the best choice of words, but English is not my native language.

So, you're not happy with reality?

alexander wrote: ↑

Mon Aug 26, 2019 12:15 am

palerider wrote: ↑

Mon Aug 26, 2019 12:03 am

Turn off the calendar, turn off the right panel, bring in the flow limitation graph.

https://i.imgur.com/DqJBXcG.png

Does it look acceptable?

No.
wiki/index.php/Sleepyhead:Organize
Or, from the link at the top of the forum that you should have read before posting:
viewtopic/t158560/How-to-post-images-for-review.html

Pugsy wrote: ↑

Sun Aug 25, 2019 2:24 pm

alexander wrote: ↑

Sun Aug 25, 2019 2:14 pm

It’s still a mystery to me why my AirSense 10 gives me a much higher pressure than what is needed in order to treat my apneas and hypopneas if I set the maximum pressure to 20. I wonder if other machines would react in a similar way.

Because it treats more than apneas and hyponeas in auto mode....snores and FLs are actually a much bigger driving force for pressure than people realize and you don't necessarily see evidence of those happening as much as a flagged event can be seen easily.

Actually its well established that the ResMed algorithm overshoots the needed pressure by a wide margin. This is a byproduct of the "fast response" that is designed into ResMed. Personally, I like to set the mask straps at the lowest force to withstand the pressure so it would drive me crazy to have the pressure run up to 15 when I only need 11. Of course, the best thing is to have the initial pressure set correctly to start.

Although some folks praise the ResMed fast algorithm, I wonder if its responsible for so many people complaining about leaks.

There is always soft response.
JPB