New to ASV - New to Any Machine - Scribed AirCurve 10 ASV

[StephenGunn]

Hi,

I was prescribed the Resmed s9 Adapt. Got to my medical equipment provider and they gave me the newer AirCurve 10 ASV instead, yesterday.

Puts out to much pressure (if I can use that term loosely not knowing if it sets off bells with strict definitions of keywords) for me when it kicks in past its ramp phase.

I got into the clinical settings but don't know what to adjust up or down.

My script from my sleep center is:
EPAP min 7
EPAP max 17
PS min 0 PS
Max 17
Rate Auto

I would like slightly less pressure at max (if possible).

My experience during 4 sleep studies all within 2 month period this past October 2014:

Sleep Study One: Couldn't hardly sleep with the 28 probes on me. Am a side sleeper but was told to sleep on back. No machine hook up. Slept maybe two hours. Was there from 8 p.m. - 5 a.m. Few weeks later received call from the sleep center and was told I have severe sleep apnea (after doctor looked at my graphs, etc.)

Sleep Study Two: I never take sleeping pills. Had 30 Ambian pills that I never used from a stint when I was in the hospital two years earlier. Took 1 ambian this night, again hardly slept. Hard to sleep at the sleep center for me. The cpap machine drove me crazy with the same pressure in and out, constantly. Couldn't think about anything except the constant rhythm of air being pushed in and out. Definitely was not my rhythm and I felt out of sync with myself. Slept maybe one two hours. Was there from 8 p.m. - 5 a.m. Was called a week later and told I failed and need to come back for a bipap study.

Sleep Study Three: Took 1 ambian, Slept maybe 3 hours. Was on bipap machine. Hard to sleep on back and was in and out the time I was there. Was there from 8 p.m. - 5 a.m. Got call back that I have central sleep apnea too and failed bipap.

Sleep Study Four: Took 2 ambian. Slept from 11:00 p.m. to 1 a.m. Laid awake from 1 a.m. till 5 a.m. During the two hours the machine pumped so much air into me that it went directly into my stomach, woke me once at around midnight. That woke me straight up, sat up in bed. It woke me up again at 1 a.m. again pumping so much air into my stomach that this time I threw up.

During my varying sleep studies, they tried me on pillow, face and nose masks but they settled on face mask. I only breath through my nose 100% of the time.

They called me and told me to come into the office to order my machine after the ASV test (vpap). There was no way I was going to do that. If I sleep on my side I have no problem. Might have episodes but I feel refreshed etc. Then two weeks back (deep into March and months after my sleep studies) suddenly my central sleep apnea got worse. I was waking up every 5 minutes all night long no matter what position I layed in. I was extremely dejected and distraught. I went into my physician and he asked me if I was on opioids. I told him no. I was diagnosed with a pituitary tumor two years back so I figure that is the primary culprit. Anyhow he said there is nothing more he can do for me and I need to get on the machine. So they ordered me this ASV machine.

Now that was two weeks ago when I started having incidents with central. Because Binson's (my medical equipment provider) was out of stock with my machine I had to wait and then Easter came and they were closed etc. I had to find a solution for myself.

Now this may sound controversial but it worked in the mean time before I received my machine yesterday. In some research I discovered that premie babies (babies born too early) can have central sleep apnea. And the government study suggested caffeine. Caffeine? The stuff I avoid so I can get to sleep? I couldn't find any no dose at my local store so asked for help from an attendant. Took about 20 minutes of her calling for help and looking for some caffeine pills. She found an 8 hour release product of just caffeine, see through capsules. Looks like little pellets inside the capsule. Not what I was looking for but I settled with it. I took one that evening but was still waking every few minutes (gasping and sucking air into my self; hurting my throat in the process). I took another pill in desperation at around 0200 and I found at around 0400 I fell asleep with no apnea (on my side). I tried a pill at 8 p.m. the following evening, went to bed around 2300 and found I slept through the night with no episodes. Obviously I may have small episodes but I didn't note any. I used this regimen until I travelled to Denver last week from Michigan (Tuesday evening, arriving back home late Friday evening). My wife and daughter went with me for a small get away. I brought enough of these caffeine pills for 1 per evening. Problem was that the first evening was horrible and I needed to take two pills. The Denver altitude probably affected me. So now I was short a pill. I also started noticing I was feeling weird and sick from taking so much caffeine before sleep. Two 8 hour capsules was too much. But just to get past Denver I needed to find some. The next day we didn't go to the Denver Zoo, our plans, but drove from one pharmacy to another store to another store to look for more of these caffeine pills (8 hour release). No one has them in Denver. Later that evening I settled on regular caffeine pills. My wife broke it into fourths for my use to mimic constant level release in my blood stream. I found the regular pills worked that night for me.

I don't want to be on caffeine at night for the rest of my life so I want to wean off them and wean onto the machine. The caffeine seemed to kick my central nervous system in the butt and get it to send messages to my lungs to breath. ''

Anyhow, now that I've have the machine one night, based on my experience at the sleep center I'm really not trusting the settings they use.

My experience last night. I did take an 8 hour caffeine pill at 8 p.m. I couldn't fall asleep until 0300 with the machine even though I went to bed at 2300. Just hard for me to get used to. During the ramp up for 40 minutes it was very easy and almost pleasurable. But once it reached full pressure it interfered with my concentration and kept me awake. I finally dozed off around 0330 but the pressure was too high overall. I'd like to lower it a smidgen. Just to adjust it. I don't want to be all over the map. Not sure what to lower though. Any help/suggestions would be appreciated.

Stephen

[StephenGunn]

Should add that I chose a pillow mask. In this case the AirFit P10. I like it.

[Pugsy]

Don't take the caffeine in the evening...it's going to make falling asleep a whole lot harder.
If you aren't asleep by the time the ramp is over...push the button to turn off the machine and then push it again to start it all over again so that you get ramp available to you again.

Your starting pressure is 7 cm EPAP(exhale)....and with PS minimum of 0...that's also your IPAP (inhale) pressure until you go to sleep and the machine thinks you are having apnea events that it needs to address.

I don't know that I would advise reducing the 7 cm minimum EPAP but I suppose you could but if it were me I would use PS to make the EPAP and IPAP a little different and it's the difference that should offer some relief.
So...change PS minimum from 0 to maybe 2 and leave everything else the same.

Ramp just starts at 4 cm and works up to 7 cm over however long ramp is set to work...up to 45 minutes...so ramp time can be changed or you can just start the machine again and use the machine's ramp time.

So...
Maybe reduce minimum EPAP to 6 and see if that is easier...no other changes
Maybe increase PS minimum from 0 to 2 and see if that is easier...no other changes
Maybe just increase the ramp time (if it is short right now) or turn machine off and back on again to get it to kick in again if you aren't asleep.

Those maximum settings you see....they really won't become a factor until you go to sleep and apnea events drive the pressures up.

[StephenGunn]

Don't take the caffeine in the evening...it's going to make falling asleep a whole lot harder.
If you aren't asleep by the time the ramp is over...push the button to turn off the machine and then push it again to start it all over again so that you get ramp available to you again.

Your starting pressure is 7 cm EPAP(exhale)....and with PS minimum of 0...that's also your IPAP (inhale) pressure until you go to sleep and the machine thinks you are having apnea events that it needs to address.

I don't know that I would advise reducing the 7 cm minimum EPAP but I suppose you could but if it were me I would use PS to make the EPAP and IPAP a little different and it's the difference that should offer some relief.
So...change PS minimum from 0 to maybe 2 and leave everything else the same.

Ramp just starts at 4 cm and works up to 7 cm over however long ramp is set to work...up to 45 minutes...so ramp time can be changed or you can just start the machine again and use the machine's ramp time.

So...
Maybe reduce minimum EPAP to 6 and see if that is easier...no other changes
Maybe increase PS minimum from 0 to 2 and see if that is easier...no other changes
Maybe just increase the ramp time (if it is short right now) or turn machine off and back on again to get it to kick in again if you aren't asleep.

Those maximum settings you see....they really won't become a factor until you go to sleep and apnea events drive the pressures up.

I appreciate your advice so much. I'm at a loss at this juncture with the varying parameters. What you suggest is light years ahead of what I was set to do with the machine. I'm going to take your comment and study it until I comprehend every component. Maybe I can have some constructive observation at a later junction.

The thing with the caffeine, I had become so tired, dead tired, that the caffeine didn't and still up to this point hasn't bothered me. You have to understand I was just a few months back and there in for years extremely sensitive to caffeine and couldn't drink it past 1400 (2 p.m.) due to the insomnia it would create. But then something pushed me down and it's almost like I need the kick in my body to tell it to do normal autonomic things. But I did mention I took two in Denver Tuesday evening and started noticing the effects, not that evening, slept well after the 2nd pill, but the next morning. Sort of like driving for 12 hours and taking caffeine (from when I was in my 20s) and being awake but not all there. I felt sort of like that last Wednesday. But ensuingly the caffeine has been fine for me, going back to minimal dosage. It was the choice of caffeine slight affect possibly the next day, with my current situation (not causing insomnia but getting me over the hump to breath) or absolutely no sleep. The absolutely no sleep 48 hours at one point was killing me two weeks back.

[StephenGunn]

Set my PS to 2. Will try that for now. My ramp time is 45 minutes. But I changed to no ramp time just now. I want to know right away how I'm going to react to these settings, etc. I can put the ramp time back in when I feel I've found the optimum settings for myself.

By the way although my script is for Max EPAP 17, the AirCurve 10 ASV only allows it to go to Max EPAP 15. I hadn't noticed they had set it to that at Binsons. I tried increasing just now to 17 but it will not allow it any higher.

[Pugsy]

First of all don't go changing any settings until you understand what you are changing.
Use the ramp function again by turning the machine off and then back on again...ramp starts all over when you do that.

It's difficult to get used to all this "stuff" that we are attached to...the mask and the machine blowing air up our nose.
Caffeine is a central nervous system stimulant and it will make all those sensations with the mask and machine amplified and make it harder to get to sleep. It will make an already potentially difficult adjustment even harder...trust me. It isn't your friend right now.

I am sort of familiar with your machine...I am currently using a slightly older model of it.
PS is pressure support or in other words the difference between inhale and exhale. Right now with PS minimum of 0 that makes your inhale pressure going to be the same as your exhale pressure and while 7 cm may seem like a hurricane right now....there will come a time when you come to think of it as a gentle breeze.
In terms of adjusting...it's actually probably a little easier breathing rhythm when the inhale and exhale pressures are different. That's why the idea to set PS minimum to 2...that way there's a 2 cm difference between inhale and exhale and I think you will find it quite comfortable.

Those maximum setting numbers that you are seeing...those are only where the machine can go to if it thinks it needs to go there and it won't go there while you are awake so those maximum numbers are a non factor while you are awake. While you are awake you are only dealing with the 7 cm after the ramp has ended.

You gotta ditch the caffeine though...it's going to make the adjustment so much harder and thus harder you to fall asleep with the mask and machine on.

How long is the ramp set for? It can be set for up to 45 minutes and if you restart the machine...you get that ramp time all over again.

[Pugsy]

By the way although my script is for Max EPAP 17, the AirCurve 10 ASV only allows it to go to Max EPAP 15. I hadn't noticed they had set it to that at Binsons. I tried increasing just now to 17 but it will not allow it any higher.

Don't worry about that right now. It's doubtful that your maximum EPAP will ever come close to 15 anyway.
I think the restriction is tied to a combination of EPAP and PS minimum and maximum.

Play with the PS min of 2 and let me know how it feels in terms of comfort.

[StephenGunn]

First of all don't go changing any settings until you understand what you are changing.
Use the ramp function again by turning the machine off and then back on again...ramp starts all over when you do that.

It's difficult to get used to all this "stuff" that we are attached to...the mask and the machine blowing air up our nose.
Caffeine is a central nervous system stimulant and it will make all those sensations with the mask and machine amplified and make it harder to get to sleep. It will make an already potentially difficult adjustment even harder...trust me. It isn't your friend right now.

I am sort of familiar with your machine...I am currently using a slightly older model of it.
PS is pressure support or in other words the difference between inhale and exhale. Right now with PS minimum of 0 that makes your inhale pressure going to be the same as your exhale pressure and while 7 cm may seem like a hurricane right now....there will come a time when you come to think of it as a gentle breeze.
In terms of adjusting...it's actually probably a little easier breathing rhythm when the inhale and exhale pressures are different. That's why the idea to set PS minimum to 2...that way there's a 2 cm difference between inhale and exhale and I think you will find it quite comfortable.

Those maximum setting numbers that you are seeing...those are only where the machine can go to if it thinks it needs to go there and it won't go there while you are awake so those maximum numbers are a non factor while you are awake. While you are awake you are only dealing with the 7 cm after the ramp has ended.

You gotta ditch the caffeine though...it's going to make the adjustment so much harder and thus harder you to fall asleep with the mask and machine on.

How long is the ramp set for? It can be set for up to 45 minutes and if you restart the machine...you get that ramp time all over again.

I had the ramp set to max 45 minutes last night. Reset to 10 minutes tonight but can take your suggestion and put back to max and reset if i'm having trouble falling asleep. I did change the ps to 2 and have been testing it while awake. But it appears you're saying I won't notice any difference (0 or 2) because it won't take effect until I'm asleep. Coming from not knowing anything about these machines to having one and the parameters, and what they in effect mean, will take a few weeks, I'm assuming, to get a grasp of.

I'm going sans caffeine tonight. 1st time since I found that as a solution. It does not affect me in the way you're saying. I know the effects of caffeine on my body. Am very sensitive to any chemicals. And this ends up being almost a life saver since the central apnea hit, something had depressed my system, is depressing my system, to the point caffeine is having very limited effect except to jump start the message to breathe.

If the current pressure will feel like a breeze later then you're saying the body will adjust. Naturally so. I just don't like it. I'm a light breather. The lighter the better. The subtler the better. Feel calmer and more balanced. This level with the machine just feels very unnatural and like brandishing something very course. It is what it is though.

Is there something I can read that explains these concepts in layman's terms. I can't seem to find any by googling. For instance ' Right now with PS minimum of 0 that makes your inhale pressure going to be the same as your exhale pressure'. So I have pressure to breath in and breath out. With EPAP the machine is helping me with pressure to breath out? I don't feel any help breathing out. Only air being forced in. And if there is a difference between the two, pressure wise, which is easier, more pressure to breathe in or more to breathe out? I see calculations on the web for IPAP but here I'm setting EPAP and PS. Not grasping it yet, obviously. And don't want to ask frustrating questions. I'm sure some where is some explanation. I downloaded the SleepyHead Software and uploaded my stats from last night. The graphs do not mean anything to me but there is no good explanation in the software, that I can find, to explain what they mean, what is better, worse and where to look to improve, etc. Seems like people on these forums have a knowledge that I lack right now.

[Pugsy]

EPAP is exhale pressure....
IPAP is inhale pressure
With the PS minimum of 0....that makes EPAP equal IPAP...because PS is the difference between EPAP and IPAP and with it set to 0....there is no difference.

PS minimum of 2 you will notice that difference while awake. That change is immediate ...it's the other maximum settings that you won't see until you go to sleep.
EPAP would be 7
PS min of 2
will give you IPAP of 9

I know it's weird sounding but 7 exhale and 9 inhale will likely be easier to manage than straight 7 inhale/exhale. The greater the difference the easier it is to feel the relief during exhale.

Believe what you want to believe about caffeine's effect on your body but the cold hard fact of life is that it is a stimulant and Murphy's law means it will likely stimulate you when you don't want it to stimulate you.

You are on a very special machine because of central sleep apnea issues. I don't recommend anyone go changing these machine's settings unless they understand what they are doing and I admit it's a huge learning curve.
The changes I suggest are very minor in the grand scheme of things but if you aren't comfortable making them and you can't get to sleep the way things are now...talk to your doctor for sure.
You need those higher maximum settings to deal with the centrals...that's simply what centrals need but you don't have centrals (or shouldn't) until you go to sleep. Now if you hold your breath...the machine is likely going to think you are having a central apnea (it doesn't know if you are asleep or not) but we don't normally hold our breath while awake long enough for the machine to think a person is having a central apnea. When breathing normally while awake the machine won't do anything beyond whatever minimum settings are present.

[Julie]

One more thing about caffeine - it's so likely to aggravate, if not induce GERD, and that's a bane of many of us, whether due to age, diaphragm problems, LES (sphincter) problems, etc.) and you can have it 'silently', but it may well cause you to arouse during sleep, if not consciously, and mess up your Cpap experience, never mind your stomach/esophagus. It's hard to stop, at least after noon-3 pm, and you could get headaches for a short time, but it's worth trying. Certainly I wouldn't use caffeine pills as they generally are stronger than just brewed cups.

[StephenGunn]

EPAP is exhale pressure....
IPAP is inhale pressure
With the PS minimum of 0....that makes EPAP equal IPAP...because PS is the difference between EPAP and IPAP and with it set to 0....there is no difference.

PS minimum of 2 you will notice that difference while awake. That change is immediate ...it's the other maximum settings that you won't see until you go to sleep.
EPAP would be 7
PS min of 2
will give you IPAP of 9

I know it's weird sounding but 7 exhale and 9 inhale will likely be easier to manage than straight 7 inhale/exhale. The greater the difference the easier it is to feel the relief during exhale.

Believe what you want to believe about caffeine's effect on your body but the cold hard fact of life is that it is a stimulant and Murphy's law means it will likely stimulate you when you don't want it to stimulate you.

You are on a very special machine because of central sleep apnea issues. I don't recommend anyone go changing these machine's settings unless they understand what they are doing and I admit it's a huge learning curve.
The changes I suggest are very minor in the grand scheme of things but if you aren't comfortable making them and you can't get to sleep the way things are now...talk to your doctor for sure.
You need those higher maximum settings to deal with the centrals...that's simply what centrals need but you don't have centrals (or shouldn't) until you go to sleep. Now if you hold your breath...the machine is likely going to think you are having a central apnea (it doesn't know if you are asleep or not) but we don't normally hold our breath while awake long enough for the machine to think a person is having a central apnea. When breathing normally while awake the machine won't do anything beyond whatever minimum settings are present.

Well last night was horrible. The pressure was too big when the centrals hit so it blew my mouth open. My system was then warning me of leaks each time, so in and out of sleep all night. The nasal pillows have no place to go with the air pressure. I went to my medical supplier and got a nasal mask. Will try tonight. I might just go on the caffeine to kick the centrals to the curb. That is much better than what I went through so far on the machine. People at work remarked how refreshed I looked three days back (before I got my machine) and thought I was on the machine; had to explain my experience and research on caffeine with premies and centrals. I guess if you're on your death bed you take a hit of adrenaline to get your heart pumping. Similar to these centrals for me. My central nervous system is depressed so the caffeine brings me back to stasis. Before I had these centrals I couldn't take caffeine past 2 in the afternoon. Now I fall asleep like a baby after taking one because it doesn't keep me up but gets my brain instructing my lungs properly. Go figure. I should sell my secret for $10.00 with one of those internet scams. 'Buy my book and I'll tell you my secret'. No one would believe the solution because of the nature of caffeine on a normal person on the cns.

[StephenGunn]

One more thing about caffeine - it's so likely to aggravate, if not induce GERD, and that's a bane of many of us, whether due to age, diaphragm problems, LES (sphincter) problems, etc.) and you can have it 'silently', but it may well cause you to arouse during sleep, if not consciously, and mess up your Cpap experience, never mind your stomach/esophagus. It's hard to stop, at least after noon-3 pm, and you could get headaches for a short time, but it's worth trying. Certainly I wouldn't use caffeine pills as they generally are stronger than just brewed cups.

You could be right. I have experience GERD frequently in the past if too acidic, coffee or orange juice or spicy foods, but mostly because I ate too much close to sleep and something in that was not settling properly. Anything sulfuric in nature seems to stimulate gerds in me too. My wife has perpetual GERDS so is on pills. When I've taken the caffeine pills no such thing happened to me, it's very, very neutral since it just gets into the blood stream quickly with a small sip of water. Nothing along the lines of Gerds occurs or happens to me. They are not churning up acid like coffee does, etc. Maybe they do for you though, I don't know. I only know my experience and I will be truthful to my experience and transparent about it. I would never assume my experience is yours or my experience is the norm. I'm up there in age now, turn 50 next year and have had my fair share of GERDs but I respect my wife's dismal experience because she burned away her valve when our daughter sat too high during the pregnancy. It's rough and a constant.

[StephenGunn]

By the way although my script is for Max EPAP 17, the AirCurve 10 ASV only allows it to go to Max EPAP 15. I hadn't noticed they had set it to that at Binsons. I tried increasing just now to 17 but it will not allow it any higher.

Don't worry about that right now. It's doubtful that your maximum EPAP will ever come close to 15 anyway.
I think the restriction is tied to a combination of EPAP and PS minimum and maximum.

Play with the PS min of 2 and let me know how it feels in terms of comfort.

I tried the PS at min 2 and it was okay. I thought I noticed a difference from PS 0 but then I thought I must be imagining it because I misunderstood your explanation that the effects do not kick in until we are asleep. Your ensuing post cleared up my misunderstanding. There is a subtle difference. So subtle that I need to put it back on 0 and lay back and feel it for 30 or so. I think I did find 2 more pleasant but in a subtle kind of way. Overuse of that word.

Anyhow, the reason I brought my ramp down to a few minutes at one point (I mentioned in a prior post I went from 40 to 10 minutes ramp) was so I could experience the pressure while awake quicker; wanted to know now if I had helped the situation. I just hold my breath and the machine thinks I'm having a central and kicks in some pressure, I wait still more, and the machine kicks in again pretty quickly with even more pressure, and the third time it kicks in while I still do not actively breathe it practically shoots my mask off, tried with my nose mask this afternoon to test her out. I am strictly a nose breather so am resistant to a full face mask at this point. Thing is when I awake I expect the pressure so clamp my mouth shut with the pillow when testing and I guess I also kept it clamped shut for the test with the pressure with the nasal mask. When I'm asleep, with the pillow last night, it blasted my mouth open every time, when the pressure got too high.

I'm learning and experimenting. I do appreciate your suggestions. I find it much more beneficial to have an educated suggestion rather than my blind mucking about with the settings. Later this morning around 5 a.m. I was pretty distraught with the centrals blowing my mouth open (the pillows would reach such a high pressure that they'd blow into my nose and blast my mouth open. Happened over and over again. I got up changed the 2 to 0, obviously no effect with the high pressure (I don't think)). I changed my 7 EPAP to a 6. Seemed like it was even better than have the PS at 2 and EPAP at 7 with normal breathing.

I don't understand what 15 EPAP means and 17 PS means. Why two settings for the max? I'm sure it has something to do with IPAP but not clear. If I lower my EPAP what will happen? If I leave my EPAP but lower my PS what would happen? I mean what would one normally expect to happen? Lower pressure, more pressure, more of difference between EPAP to PS so higher/lower IPAP. I'm willing to experiment with a notch or two in either direction (well can't go higher with EPAP) but you're of the opinion I probably never reached 15 with my EPAP. The charts with SleepHead seem to tell me I had hit my max two nights ago at various times in the night. I do know the machine increases pressure incrementally and appears to pump out air at a higher interval each time it believes I still haven't breathed. I don't have a clue how long I go without breathing when I'm asleep. 10 seconds, 30 seconds, etc. That would certainly help explain a very high pressure from the machine. I didn't upload to my computer last nights.

[Pugsy]

EPAP....exhale pressure
IPap....inhale pressure
PS..pressure support which is nothing more than IPAP minus EPAP.

EPAP is need for obstructive apnea events...
IPAP mainly in your situation is needed to be fast and high for the centrals....that's how centrals are treated...with a rather quick big burst of air to sort of jump start your respiratory system.

The pressure blowing the mouth open...I see pressures of 22 nearly every night and my mouth doesn't fly open because I have learned to position my tongue so the air that is going up the nose and down the airway doesn't enter my mouth.
With time and experience you can learn to do this too. Place your tongue in the roof of your mouth...it will block the air from entering the mouth..easy to do while awake but when we fall asleep the tongue gets lazy and falls back and air rushes into the mouth and cheeks puff out (we call that chipmunk cheeks) and then it blows the mouth open.
If you can't get your tongue to be a better door and block the air from entering the mouth then you will need to get a full face mask because if too much air escapes through the mouth then your therapy isn't effective...
but it still may wake you up...so need to work on the tongue positioning thing. It takes a lot of practice though.

PS of 2...that means your inhale pressure is going to be 2 cm more than exhale pressure.
PS of 2 isn't that big of a change and I am not surprised that you could barely tell any difference.
Just for fun to try so you can really feel the difference...try minimum PS set to 4..and see how it feels.

ASV therapy for centrals...for some people it's a walk in the park but for others it's a huge adjustment so don't despair if it takes you some time to get all this stuff sorted out.
Cpap can be difficult enough and you unfortunately have to deal with rapid and high pressures where regular cpap users don't have to deal with such rapid and high changes.

Quit trying to hold your breath to get the machine to kick in....it's a waste of time and accomplishes nothing.

[bwexler]

First I wish I could get as OLD as you again. Haven't seen 50 in almost 20 years.

I also use an ASV machine. To understand the max pressure, you need slow down and understand that you have an auto adjusting machine.
The first thing it can adjust is is EPAP. It can move any where from EPAP MIN to EPAP MAX, in you case 6 or 7 to 15. Next it can adjust PS from 0 or 2 to 17. that means it will add the ps to the EPAP or 6 to 32. The machine max is 25 so it can never go over 25.
For some people increasing the EPAP MIN to the point where it stops all the obstructive apnea and most of the centrals and reducing the PS MAX so the range is reduced, for example EPAP MIN 10 EPAP max 15 PS MIN 2 PS MAX 5 would give you a range of EPAP 10 IPAP 12 to EPAP 15 IPAP 20. I am not recomending these settings for you or anyone, just using them to explain how the settings work.

I hope this helps to clear up some terminology for you.

I am still trying to fine tune my own settings after a year and a half on the ASV,