Increase or Decrease Min EPAP?

[djhall]

I'm new to treatment and I've been finding the right mask and settings combination to settle into for the past two weeks. For the past week I have been running my PR System One BiPAP Auto on auto with Min EPAP: 15 and Max IPAP: 25. The reasoning behind that setting was my average 90% pressures are 17 / 19.5 and I had read on the board that too large a gap between your minimum and your average could potentially result in larger numbers of incidents, it could take longer before the machine climbs high enough to control clusters of incidents, and large pressure changes are not tolerated well by some people. On the other hand, I have also read many people prefer letting auto machines decrease the pressure further if there are long stretches where pressures of 15+ aren't necessary in order to reduce the side effects of spending long times at higher pressures.

This is data from last night, and very typical of the last week spent at these settings:

[/img]http://dl.dropboxusercontent.com/u/21847891/Sleep.jpg[/img]
https://dl.dropboxusercontent.com/u/21847891/Sleep.jpg

I tend to spend long stretches at the minimum EPAP of 15 with occasional random events. However, spaced throughout the night are around three distinct clusters of OA and CA events happening one right after another for six minutes or so. During this time the machine increases EPAP to between 17 and 20. My average AHI is 3.5 to 4 with roughly 3 times as many OAs as CAs.

Here is the question I am considering. It seems like increasing Min EPAP would reduce the number of OA events in those clusters and may improve my AHI as long as I don't get increased CAs from the pressure increase. On the other hand, I see a pattern of long periods of time spent at minimum with large climbs for short periods, so perhaps I shouldn't be chasing the peaks but rather look for the minimum EPAP that doesn't cause a proliferation of OAs and let the machine adjust to those clusters of events over the six minute periods where they happen in order to get the least pressure for the most amount of time.

Any advice on whether I should be looking at increasing the pressure for fewer total events or looking at decreasing the pressure for a lower pressure for those long stretches in between the clusters?

[djhall]

Oh, and can anyone tell my why the picture doesn't display?

[jdm2857]

From your pressure graph it looks like you have PSmax set to 4. Is that correct?

I don't think that lower EPAPmin is the way to go. Two centrals are not a problem at all.
Try inching up EPAP min to 16 and see what happens. You may even want to go up to 17 eventually.

But let's wait to see what Miss Pugsy has to say.

[djhall]

From your pressure graph it looks like you have PSmax set to 4. Is that correct?

I just double checked the machine and the PSmax is set to the maximum settings of 8 like I thought. I wanted to see what the machine would do if I gave it the option to go higher, but apparently it doesn't think it needs any more PS.

I don't think that lower EPAPmin is the way to go. Two centrals are not a problem at all.
Try inching up EPAP min to 16 and see what happens. You may even want to go up to 17 eventually.

But let's wait to see what Miss Pugsy has to say.

That is the direction I was leaning... as long as the pressure isn't cause side effects, I would think fewer OAs is more important that lower pressure just for the sake of lower pressure. I know chasing a 0 AHI is impractical, but actually seeing my breathing flatline for long stretches and then come back in a burst of giant gasps on the flow report somehow is making it more real than just a number or a concept.

[jdm2857]

PSmax set to 8 is pretty severe. Imagine the pressure changing by 8 with each breath.

On the night you showed, PS never went above 4, so this was not a factor that night.
Most people on the forum say that PSmax set to 3 or 4 is good.

[djhall]

PSmax set to 8 is pretty severe. Imagine the pressure changing by 8 with each breath.

On the night you showed, PS never went above 4, so this was not a factor that night.
Most people on the forum say that PSmax set to 3 or 4 is good.

Agreed. I just thought it would be interesting to leave it open and see if the machine ever decided taking it higher was a good idea. So far (which is only two weeks) the machine has never decided to try taking it above four. I'll probably take it down some the next time I adjust the settings.

[jdm2857]

The first night I used my BiPAP, I setup the machine when I was very tired.

I wanted Auto mode, but wound up setting up straight BiPAP with EPAP = 16,
IPAP = 25, and a resulting all-night-long PS = 9.

It was not a fun night.

[djhall]

The first night I used my BiPAP, I setup the machine when I was very tired.

I wanted Auto mode, but wound up setting up straight BiPAP with EPAP = 16,
IPAP = 25, and a resulting all-night-long PS = 9.

It was not a fun night.

I saw that post. Thanks for being open enough to share that experience with us... I laughed off an on all day remembering that, thinking of how easily I could see doing the same thing, and imagining how it would feel at the moment you realized what you had done!

[DoriC]

I believe PS=4 is the default on both PR and S9 and is supposedly most comfortable and the setting of choice. When we use auto mode, we use PS=2 because my husband is sensitive to the changing pressures.

[racprops]

Well in my case I find I can hardly stand any PS Min.

I find that as PS min adds to the EPAP Min and thus my base line of EPAP min of 8.5 pumps up and adds to what ever I set the PS Min. So if I run a PS of say two I then get the 8.5 on exhale but I get 10.5 in inhale.

I also seem to get a lot of the machine trying to control my breathing rate and interfering with my own rate, and many times as I relax I find it not keeping up with the fact I am breathing slower and less deeper. I really do not like how this make my mask to pump on and off, like it is doing pushups.

To fix this problem I cycle the machine to off and then just restart again. Normally it picks up my slower and lower rate.

Thing is I do find the machine over riding my base line if it needs to.

Check out this evening's first sleep cycle: the gaps are where I turned it off and at one point I reset the PS min back to 0. I had been running PS min of 2 then 1.5 and again found the machine fight me so lastly back to 0.

Note the Mask Pressure (Blue graph) note its thickness at first and then after I reset PS Min and then just before I woke up almost on my back how it over rode my base setting and raised the EPAP Min up to around 12.



Rich

PS IF you like long sagas look up my name for my other threads about my fight with ASV and positional apneas.

Here is one: viewtopic.php?f=1&t=89838&st=0&sk=t&sd=a

PPS Looking at that mask pressure make me note how it keeps raising the pressure, I am thinking I may need a higher EPAP Min...

LATER THIS SAME NIGHT:

OK I still cannot stand much over 8.5 fighting my exhales..and for some reason 10 is the trigger point where my machine gets trigger happy and starts fighting me.

SO I ended up back with EPAP Min of 8.5 and a PS Min of 1 which on the screen shows E 8.5 and I 9.5 and I seem to like it.

Readings again now for the second sleep cycle:



For me the settings you suggesting/running sound insane...

PS ADDS to your EPAP min so on a ASV machine you get a low exhale and a high inhale..

Like mine 8.5 PLUS PS Min of 1 = 9.5 inhale

My 2 cents worth...for what it is worth hope this helps

Rich

[RandyJ]

I believe PS=4 is the default on both PR and S9 and is supposedly most comfortable and the setting of choice. When we use auto mode, we use PS=2 because my husband is sensitive to the changing pressures.

I believe default PS on PRS1 Bipap Auto 750 is 2 when you first turn on the machine in Auto mode. After that, depending on your max PS setting, EPAP and IPAP can get further apart as pressure needs change. If you set max PS at 4, EPAP will not change until IPAP increases by more than 2 cm (and they will never be more than 4 cm apart). At least, that is how I understand it for Auto mode only.

Some people like the roaming pressure support of this model because if you open it up as wide as it will go depending on your settings, if PS is set to 5 or 6, IPAP can range that high while EPAP will not change unless it needs to.

[RandyJ]

Oh, and can anyone tell my why the picture doesn't display?

After you save jpg to your public folder in Dropbox, do "copy public link" by right-clicking on the file, then paste that link between the 2 [img] commands in the message composer. Do Preview before posting your message to make sure you can see the image. If you can't, you didn't do it right.

[DoriC]

I believe PS=4 is the default on both PR and S9 and is supposedly most comfortable and the setting of choice. When we use auto mode, we use PS=2 because my husband is sensitive to the changing pressures.

I believe default PS on PRS1 Bipap Auto 750 is 2 when you first turn on the machine in Auto mode. After that, depending on your max PS setting, EPAP and IPAP can get further apart as pressure needs change. If you set max PS at 4, EPAP will not change until IPAP increases by more than 2 cm (and they will never be more than 4 cm apart). At least, that is how I understand it for Auto mode only.

Some people like the roaming pressure support of this model because if you open it up as wide as it will go depending on your settings, if PS is set to 5 or 6, IPAP can range that high while EPAP will not change unless it needs to.

Right, thanks for correcting that, I forgot about the different "dance floors" that PR and S9 use!

[jdm2857]

If you set max PS at 4, EPAP will not change until IPAP increases by more than 2 cm (and they will never be more than 4 cm apart). At least, that is how I understand it for Auto mode only.

With PSmax set to 4, increases in IPAP will not affect EPAP until IPAP rises to 4 cm above EPAP. After that every increase in IPAP will drag EPAP up along with it.

But EPAP can affect IPAP, too. EPAP can rise without affecting IPAP until EPAP rises to 2 cm below IPAP. (2 is the unchangeable PSmin on System One BiPAPs.) After that, every increase in EPAP will push IPAP up.

And IPAP has pressure priority. So decreases in IPAP can push EPAP down, but decreases in EPAP cannot drag IPAP down. Once EPAP drops to 4 cm (PS max) below IPAP, further EPAP decreases can not occur unless and until IPAP decreases on its own.

[jdm2857]

It's Saturday and Dori is thinking about dancing.

Any plans for tonight?