Need help with Bipap settings

Last year, my wife took an at-home sleep test that recorded an AHI of 6 or so. She was prescribed a CPAP machine but had difficulty using it because she found it difficult to exhale. Her doctor recommended a titration study during which she had difficulty falling asleep. But based on about an hour's worth of data, the lab recommended a bipap settings of EPAP 9 and IPAP 13. She was given a Resmed Aircurve with those settings in S mode.

She has been diligent at using the machine and she is now able to keep the mask on with manageable leaks most nights. Unfortunately, the therapy does not appear to be working. The reported AHI has been anywhere from 8 to 12. Her doctor has been unresponsive to her concerns which has been very discouraging.

I have been using CPAP (Redmed 10 Autoset) for many years and she was desperate enough to let me try adjusting her machine. I assumed that the reason for the high number of events was that the pressure was not high enough. So I changed the mode to VAuto and set EPAP to 7 and IPAP to 21. The AHI was significantly lower. However, she had difficulty with leaks and difficulty exhaling and only wore the mask for a couple of hours.

My next adjustment was to set EPAP to 5 (which I understood from reading some posts resulted in an effective exhalation pressure of 9 cm when the PS setting was taken into account) and IPAP back to 13. Her sleep was even worse than what she experienced in S mode with an AHI of 21.

I have grabbed a series of screenshots from Oscar showing the data for the nights I discussed above. I have them on Imgur (https://imgur.com/a/5bvJXjH) as I didn't want to crowd the post with a dozen images. But I will also paste the last three below in case they are sufficient at giving you a sense of what is going on.

I would appreciate any feedback or suggestions anyone may have. Thanks in advance.

Reed

Give these settings a try.

Mode....VAuto
Minimum EPAP....set to 9 cm
Maximium IPAP....set to 20 cm Increasing this setting from the 13 currently in use will allow the machine to go higher only when needed.
PS of 4
Leave the other settings at the factory defaults.

Looks like she needs more than 13 IPAP at times during the night but not other times. I would suspect either REM stage sleep related or maybe she's on her back causes more obstructive events and 13 simply isn't enough during those times.

You can't do attachments...the storage is full and we can't get it emptied.
Continue to use imgur to hose your images and provide links.

Thank you for the recommendation, Pugsy. You are right that she's a back sleeper.

One two-part question, if you don't mind. Rebecca has been complaining about not being able to breath out. Wouldn't raising the EPAP to 9 make that more difficult? And would leaving the EPAP at the current setting of 5 (which she did not complain about last night) still allow the IPAP setting of 20 to work as expected?

Edit: I just reread the explanation of VAuto mode in the clinician's guide and it appears that I was mistaken about how the IPAP, EPAP, and PS settings are used. My understanding now is that when the machine raises the inspiration pressure, it will also raise the expiration pressure so that the difference between those two values is exactly the PS value. For some reason, I expected the machine to vary those two pressures independently based on what you needed.

Reed wrote: ↑

Tue Jan 23, 2024 7:20 pm

For some reason, I expected the machine to vary those two pressures independently based on what you needed.

The other brand's autobilevel (BiPAP) works that way; ResMed's autobilevel (VAuto) keeps the difference (or, delta) constant in order to stabilize the work of breathing, since that PS (or, pressure support) generally turns out to be the most important aspect of bilevel/autobilevel for most patients, both in terms of comfort and results.

So, yes, the other brand's autobilevel has the two pressures, breathe in (IPAP) and breathe out (EPAP), dance seperately like a modern dance couple, varying their distance from one another. ResMed autobilevel, on the other hand, locks in the distance between the dancers like a traditional dance as the two pressures move in perfect unison as needed within the size of dancefloor you set with the minimum and maximum.

I personally found ResMed's approach worked much better for me than the other brand's approach, back when I used autobilevel.

Okay...if she can handle minimum EPAP at 5 then go ahead and start with that.
Keep PS at 4
for sure increase the max IPAP...and I suggest 20
We need her to sleep first and foremost and we can worry about if she needs more minimum later.
The machine will increase if it feels the need and hopefully she will be sound asleep and not know what is going on.
We will worry about increasing the minimum EPAP later if it appears it is needed. Perhaps we could increase it in smaller increments to make it an easier adjustment.

And yes....PS is fixed and won't/can't vary.

The pattern of OA events...looks very suspicious for REM stage sleep. Do you know if her sleep study mentioned anything about her OSA being worse in REM?
It's fairly common for people to have their OSA be worse or need more pressure during REM (I have that myself) along with supine sleeping well known to make OSA worse and/or need more pressure.

Right now the important thing is for her to sleep as soundly as possible so the machine can do it's job.

I am familiar with this model machine because I use it myself and

Don't use the ramp if she is using the ramp. It's not going to do much with the EPAP at 5 anyway because ramp starts with EPAP at 4.

lazarus wrote: ↑

Tue Jan 23, 2024 8:11 pm

I would use the exact settings Pugsy suggested and then post here the links to imgur (or similar) for her to see the results. Nine is not that high, really. If that minimum EPAP needs to be lower for comfort later, that can be done then.

She's not comfortable exhaling at the higher EPAP so in this situation let's back it off for now anyway and give her a chance to get comfortable and sleep.

Main thing is using auto mode and a higher IPAP max anyway.
That's the most important thing at least at this time.
I want to see how high it really needs to go to break up those clusters.

If we find she needs more minimum EPAP we can back up and do smaller increases to make adjusting easier.

We need her to sleep and if she isn't comfortable she isn't going to be able to sleep.

I just realized....home study. Probably didn't record sleep stages at all.
Probably was a Type 3 home sleep study.

I agree. I deleted that portion of my response. Either way works. You do good work. Comfort vs efficacy, and all.

Thank you, Pugsy and Lazarus. I'll have Rebecca take a look at your latest responses tomorrow. After we discussed your earlier suggestions, she wanted me to make changes incrementally to let her get used to managing leaks before dealing with exhalation issues.

The current plan is to leave the EPAP at 9, which she's been comfortable with for the past several months, and raise both the IPAP and the PS by 1 cm each night. As I now understand it, that will keep both the EPAP and IPAP constant throughout the night.

Once the IPAP is at 20 (with a PS at 11), we'll start decreasing only the PS by 1 cm each night to let her get used to higher exhalation pressures.

These two testing periods should tell us what IPAP pressure best handles the events and the maximum EPAP she is comfortable with. So we may be in a better position to pick the settings to use.

I very much appreciate your support.

Reed wrote: ↑

Tue Jan 23, 2024 8:58 pm

Once the IPAP is at 20 (with a PS at 11), we'll start decreasing only the PS by 1 cm each night to let her get used to higher exhalation pressures.

No...no...no. I doubt seriously her IPAP will go to 20.
If you use 9 EPAP and max 20 IPAP with PS of 4 then EPAP is 9 plus the PS of 4 so IPAP will be 13 and THEN with the available IPAP the machine will increase both EPAP and IPAP in small increments depending on whatever events she is having to cause the machine to increase the pressure. It doesn't go straight to 20 IPAP bringing EPAP up to 16.
Just because it can go to 20 doesn't mean it WILL go to 20.

Please use the suggestions I made....5 EPAP minimum is acceptable trial right now and who knows we might get lucky and she won't need the 9 EPAP. It will be easier...and don't go messing with PS....please, please stick with PS of 4.
5 Minimum EPAP and max IPAP of 25 is what I use and I also use PS of 4. Looking at my reports my max IPAP might hit 14 during REM and then my EPAP is 10.

Use the VAuto mode....
Do NOT use S mode with EPAP of 9 and IPAP of 20. That's a horrible choice and could potentially cause a bunch of central apneas.

Reed wrote: ↑

Tue Jan 23, 2024 1:17 pm

Last year, my wife took an at-home sleep test that recorded an AHI of 6 or so.

IIWY I'd get that report. One wonders about the validity/accuracy of the test, and for that matter, of your current data.

I'll bet they're all aggravation centrals from rasslin' with a machine she don't need.

Pugsy wrote: ↑

Tue Jan 23, 2024 9:22 pm

No...no...no.

I've read enough of your comments on this board over the years to know not to argue and do what you say

Rebecca ran the machine at 5/20 as you recommended. Here's what the night looked like: https://imgur.com/a/MVbB5dN. She had no issue with leaks despite the occasionally higher IPAP and no trouble breathing out when the EPAP peaked.

She felt better today than she has in a long time. So she's okay continuing at the current settings to accumulate more data. That is, of course, unless you suggest modifying something.

Thanks again for your support.

Some success but still needs work....just a little bit more max pressure.
See how she has clusters up at 20 and the machine wants to higher. Let's let it go higher.
I bet those clusters are REM stage sleep related. It's fairly common and I have REM worse OSA myself.
In non REM sleep my AHI is a mild 12 per hour but in REM I hit 53 per hour with desats to low 70s.
Those clusters sure coincide when we might expect to be in REM.
You can google "sleep stages" and see the normal graphs and note where REM stage sleep usually happens.

I just want to break up the clusters a little more.
If letting the machine go higher doesn't accomplish that goal then we will increase that minimum a little bit.

So one change tonight.....increase that max IPAP to 25

I will bet you the sum of $1 million Canadian ($3.80 US) you are chasing centrals.