ASV vs CPAP etc. for OSA - greater tolerability ???

Oh... it's about time I learned that eh?

Julie wrote: ↑

Sun Mar 01, 2020 4:34 pm

Oh... it's about time I learned that eh?

that's why i never respond to any thread that isn't strictly apap. i barely understand THAT without the alphabet soup of other devices!!


oh wait! i just responded in such a thread.

Thank you "squid13" (my Dad retired from the Navy in 1981 - I'm a total Navy brat!), "pugsy", "garlford", "julie", etc. for your targeted and helpful replies!

The only thing I know about ASV is what I heard on the Park/Krakow podcast. Dr. Krakow had difficulty explaining how ASV works, but said something about the "VOLUME" being less. I understood him to mean that there was less volume of air being blown with each breath, but perhaps that is not what he meant. After reading pugsy's reply I'm now thinking that Dr. Krakow may have meant less TOTAL volume due to the fact that pressure is low until an event occurs that necessitates increasing the pressure. Can anyone help clarify this?

Perhaps ASV would be no better than a BPAP set at the minimum 4 & 4 with the option to increase the inhalation pressure incrementally as tolerated (assuming I could even fall asleep with it at all!). What is the absolute minimum settings on an ASV?

The time I had an APAP to try, I actually did fall asleep ONE time (the ONLY time) during a nap. But I wasn't asleep very long before I was awakened with intolerable pressure that had me so bloated and unable to breathe even after taking the mask off that I had to sit up for a considerable length of time taking short breaths while waiting for the bloating to finally resolve. I'm assuming that it wasn't a quick increase in pressure that did that, but that the pressure was gradually increasing over minutes until it became so intolerable and had me so bloated and unable to breathe that it awoke me. Perhaps with an ASV, if as squid13 said it goes up and down so fast, maybe it wouldn't do that.

I wasn't familiar with the acronym ""EPR" and had to look it up just now. I see that it is "expiratory pressure relief." When I had what I'm pretty sure was a BPAP, I don't remember that terminology, but C-FLEX sounds very familiar. I'm having difficulty differentiating EPR, A-FLEX, BiFLEX, and C-FLEX to determine which would give the greatest pressure relief. Regarding EPR settings 1-3, what is the absolute lowest relief setting you can get? If the inhalation pressure were set to the minimum of 4 and the EPR set to 3, does that mean you would only have an exhalation pressure of 1? That would be great!

Regarding masks, I only ever tried nasal masks and nasal pillows, never full face. I did not like nasal pillows. They felt more "claustrophobic" for my nose, they irritated my nose, when the humidifier was used it caused water vapor to accumulate and run down my throat choking me, plus I couldn't stand the feeling of it resting on my upper lip. The most comfortable mask combo I settled on was the Swift FX Nano Nasal Cushion paired with the Swift FX Bella over-the-ear headgear. Unfortunately, I see that isn't offered anymore. The most interesting mask I see now is the AirFit N30, but I wish that over-the-ear headgear was still available as I definitely liked that the best.

Lastly (maybe should have been first) here is my "apnea condition":
(1) 2008 in-lab study, nearly a failure, only 3.1 hrs of sleep, but AHI of 7.7, 8 central, 4 obstructive, 12 hypopneas
(2) 2013 home study, 8.2 hrs. sleep, AHI of 5.5 but supine AHI of 11.4, 2 central, 42 obstructive, 26 hypopneas
(3) 2014 home study, 7.4 hrs. sleep, AHI of 5.7, 0 central, 28 obstructive, 14 hypopneas
(4) 2019 home study, 9.1 hrs. sleep, AHI of 14.1, 0 central, 70 obstructive, 59 hypopneas

Regarding my inability to tolerate PAP treatment, I know that it is challenging for everyone to varying degrees. But if I am correct in believing that I have significant UARS beyond any actual OSA, based on the info from Dr. Steven Park and Dr. Christian Guilleminault, UARS patients that fit my mold of younger/smaller/don't snore tend to have highly sensitive nervous systems and have a hard time tolerating PAP at all. Migraineurs also are known to have highly sensitive nervous systems, especially chronic migraineurs, of which sadly I am. But I have believed for the past few years (based on lots and lots of research and lots and lots of self evaluation and experimenting) that I will NEVER get a handle on my migraines unless and until I can solve the OSA/UARS. So here I am again, trying to settle on the best option and course of action.

Thanks again in advance of answers and advice.

reneevanv wrote: ↑

Mon Mar 02, 2020 4:21 pm

Regarding EPR settings 1-3, what is the absolute lowest relief setting you can get? If the inhalation pressure were set to the minimum of 4 and the EPR set to 3, does that mean you would only have an exhalation pressure of 1? That would be great!

No, unfortunately if the lowest the machine will go is 4 cm then using EPR of 3 does absolutely nothing because the machine is already at the lowest it will go.

The lowest available (and only on a couple of machines) is 3 cm.

Dr Krakow has long pushed for ASV machine for essentially everyone. His latest is that he thinks it helps people with insomnia and it is possible I suppose but only if the insomnia is caused by something the machine can fix. I have sleep maintenance myself but it's not airway related so the most optimal cpap/apap/bilevel/ASV therapy in the world can't do anything about my insomnia because it's related to other health issues.

I don't remember which machine or which mode...but some ASV machines will go down to 3 cm as the lowest pressure.
I am sorry but I don't remember which brand or which mode and I have been ill and just don't feel like researching it.

All the Flex setting options and EPR...just various names for exhale relief and they create a bilevel pressure situation when used.
One pressure for inhale and a drop in pressure for exhale. Actually the bigger the drop...the easier it is to exhale. I know it sounds weird but a setting of 7 inhale and 4 exhale is going to be easier to breathe with and exhale with than a fixed setting of 4 inhale and 4 exhale.

Bloat, gas, painful belly from aerophagia is a fairly common side effect from any cpap therapy. Bilevel is the first thing to try though in hopes that a nice combination of lower exhale along with the inhale will effectively keep the airway open. Works for some but not everyone so sometimes people have to make a decision as to which is the biggest problem.

Thanks for the info Pugsy. So sorry you have been ill. That's okay, you don't need to research the machine for me. )

What I've just learned from another post (viewtopic/t43371/EPR-and-BiPAP-is-there ... rence.html) is the difference between pressure relief such as EPR and BPAP. EPR type relief can ONLY go down as low as the settings allow (i.e. only 3 less than your inhalation pressure), whereas BPAP allows you to actually separately set the inhalation and exhalation pressures. So in theory, you could have an inhalation pressure of 20 but an exhalation pressure of only 4.

reneevanv wrote: ↑

Mon Mar 02, 2020 6:44 pm

So in theory, you could have an inhalation pressure of 20 but an exhalation pressure of only 4.

In theory..yes...but it's not anywhere near a realistic goal. I once tried 25 inhale and 18 exhale so just 7 cm difference and it was not very pleasant having just the 7 cm difference. Plus I am not sure but I think some of those bilevel machines have PS limited to 15 max and you couldn't do 4 exhale and 20 inhale because that would be 16 PS. Too much PS can cause centrals. I had a friend who one night decided to try 10 exhale and 20 inhale so PS of 10 and she was in a panic the next day because she had a truckload of central apneas pop up.
When she dropped it down to 5 PS...the centrals all went away.

Most people will be using 4 to maybe 6 cm pressure support (the difference between inhale and exhale when using bilevel settings).
When people use EPR or the other exhale relief options...they are creating their own limited bilevel machines within the limitations of the machine settings. EPR on the ResMed is limited to a 3 cm difference....Respironics Flex relief is limited to 2 cm max difference because they base how much relief you get on how forcefully you breathe.
I can use EPR of 3 but I really like the 4 cm difference I can get with the bilevel machine.

Hmmm, okay, I get it.

So I never made any kind of notes of what various settings my doctor prescribed on the various machines I had during the two times I tried them (2008 & 2014). So I don't really know what the inhalation/exhalation settings were on the BPAP. It may have been 6 & 4, at least that is my vague recollection. I can dig through my paperwork and see if it lists the actual machine names, but that was the initial paperwork and I don't know if I got paperwork with machines that were switched out. It looks like the APAP I briefly tried was a Resmed S9 AutoSet. I'll have to look tomorrow (if I remember) to see what other machines were.

reneevanv wrote: ↑

Mon Mar 02, 2020 8:37 pm

Hmmm, okay, I get it.

So I never made any kind of notes of what various settings my doctor prescribed on the various machines I had during the two times I tried them (2008 & 2014). So I don't really know what the inhalation/exhalation settings were on the BPAP. It may have been 6 & 4, at least that is my vague recollection. I can dig through my paperwork and see if it lists the actual machine names, but that was the initial paperwork and I don't know if I got paperwork with machines that were switched out. It looks like the APAP I briefly tried was a Resmed S9 AutoSet. I'll have to look tomorrow (if I remember) to see what other machines were.

Your medical records belong to YOU.
If you cannot find your notes, ask your previous doctor for those settings,
and copies of relevant sleep studies.
That will help reveal what kind of machine and what settings you need.
Good luck this time around.

Looking through all my old paperwork and brochures:

It looks like the first machine I had in 2008 (supplied by Apria) was a Respironics REMstar Auto M series (had C-flex?)
Then it looks like maybe I still had the same machine but it was switched from Auto to CPAP ??? Is that possible???
... I just looked at an article on a CPAP supply site and apparently it is!

I don't have nearly as much paperwork for 2014 (DME supplier changed to our local hospital insurance one).
I have a prescription that looks like I once again had a change from autoCPAP to just CPAP 6 cm.
I don't remember that, although I DO remember an issue with what they first sent me home with not being what I was supposed to have and I seem to remember it being set intolerably high from the beginning.
Anyway, it looks like the machine that I ended up with was a Resmed S9 Elite CPAP.

Apparently I never DID have a BiPAP machine, contrary to what I thought. I guess the pressure relief I had was only the C-flex option on the first machine. I don't even see any pressure relief option on the S9.

Pressure relief on the Respironics machines with any kind of Flex is limited to 2 cm drop and you get that only if you are a forceful breather. Not much drop.

ResMed machines have EPR and there is up to a 3 cm drop available and you get it no matter how forcefully you breathe....but EPR has to be turned on so we don't know if it was even turned on in your past situation and if it was turned on ..at what setting did you get to try.

Using any form of exhale relief does create some bilevel pressures because bilevel just means 2 different pressures. One for inhale and one for exhale....so a cpap/apap machine can behave like a bilevel machine with some limitations.

Using available exhale relief on a cpap/apap to create a bilevel pressure situation has some limitations though....the maximum amount of drop during exhale.
A real bilevel machine can have more of a difference than the 2 cm that Respironics might give a person and the 3 cm that ResMed can give with exhale relief.

Thank you so much for the info!

Pugsy wrote: ↑

Tue Mar 03, 2020 9:47 pm

Pressure relief on the Respironics machines with any kind of Flex is limited to 2 cm drop and you get that only if you are a forceful breather. Not much drop.

ResMed machines have EPR and there is up to a 3 cm drop available and you get it no matter how forcefully you breathe.......but EPR has to be turned on so we don't know if it was even turned on in your past situation and if it was turned on ..at what setting did you get to try.

Very true! I'm discovering that I really did not know what I had and I wasn't aware that there were potential options to even ask for! It does seem that I had some exhalation relief, however, so maybe it was the c-flex 2 cm and I'm not a forceful breather so I continued to struggle. And as you said, who knows what I had with the ResMed?!

Pugsy wrote: ↑

Tue Mar 03, 2020 9:47 pm

Using available exhale relief on a cpap/apap to create a bilevel pressure situation has some limitations though....the maximum amount of drop during exhale.
A real bilevel machine can have more of a difference than the 2 cm that Respironics might give a person and the 3 cm that ResMed can give with exhale relief.

That is why I started thinking about bilevel, because I REALLY feel like I would need significant exhalation relief. ... but I see the huge price difference! And since I wasn't diagnosed with CSA or complex, I don't know that the doctor would give me a script for one.

I had some notes scribbled both for the Respironics in 2008 and the Resmed in 2014. In '08 I complained that the pressure increased up to 8 while I was on my back and caused me to overinflate (I was still awake). In '14 I apparently told the doctor that at one point the Resmed went up to 11+ even while I was still awake. (At this point I have no idea if that was when they were set to auto, or maybe that was when they were set to CPAP and he had it set that high so the ramp feature took me up there while I was still awake unable to fall asleep.)

More and more I think I need to get my own machine that I can adjust myself until I can comfortably fall asleep with it! Then and only then I can see what the results are to know what pressures I might actually need. Knowing what I now know, maybe with conservative settings I could actually get to the point of actually tolerating, say, an AirSense 10 AutoSet For Her? (as was suggested to me on my other post) I really had NO idea what they were setting the machines at before. No wonder I could never tolerate them!!!