Help refining CPAP settings to control Obstructive Events and Central Events/Are Cent

[sherwoga]

11-16-2019, 12:00 PM
RE: Help refining CPAP settings to control Obstructive Events and Central Events/Are Cent
As SR has said nothing has really changed, you are lowering your pressure with no ill effects and we want to continue that at least until we see a bump on obstructive events A pressure of 7 is the lowest I would go (7/4 with EPR=3) for anyone without a specific reason to go lower.  

I see you with an EPR=3 AND on EERS (start with a tube length of 6 inches) to manage your Centrals.  The EERS is totally your choice, but I believe that the EERS allows you to use Pressure Support and pressure (EPAP) to treat your obstructive events while managing your central apnea. this was unheard of until recently.  The fact that this requires equipment (Mask) modification will make it unacceptable to some and both I and SR will understand that.  Without EERS you have a choice of where to balance between Obstructive and Central evets, never fully treating either.  It's not a bad approach and is what has been traditionally before.
Fred Bonjour - Project Manager and Lead Tester for OSCAR - Open Source CPAP Analysis Reporter 
OSCAR

Regarding you recommendations to lower Maximum Pressure incrementally with EPR off: 

11-13-2019, 09:40 AM
RE: Help refining CPAP settings to control Obstructive Events and Central Events/Are Cent
Your pressure is being driven by Flow Limits.  And you have a couple of RERAs, not enough to worry about but they also are an indication of Flow Limits.  To deal with the flow limits I would have you set your EPR to 3 (don't) but we know what will happen there.  For you it is better to balance toward fewer centrals (EPR=0).  

Narrow pressure band,  There is some logic and reason to do so.  It is, on CPAP and BiLevel machines, the next step to reducing Centrals.  18+ is 'safe' territory for you, remember that.
Drop Max to 16, I don't expect you to feel much different. then try reducing 1 cmw every couple of nights until you reach 13 and let it sit there for a couple of nights to settle in.  See if that improves how you feel?

This was post #13 in this thread.

Should I proceed to 13?
Current status:

1. EPR - OFF
   
2. Max Pressure - 14
   
3. EERS - I followed SR's advice and requested sources/parts/fabrication information from previous EERS users. I got a terrific response from all three named users and have seen a lot of dialog regarding a new thread with more details on the EERS fabrication.  I am in the process of getting the equipment from Slowriter.  It will arrive today, probably late, maybe too late to get it ready for tonight, but am exited to get it into service.  And I plan to contribute to the EERS fabrication dialog as I get my act together.  
   

Observation/Question:  Last night was the 2nd night at max pressure of 14 (see attached OSCAR output).  The mask pressure topped out at 14 multiple times in the night, i.e., the system seems to be operating at my currently imposed limit.  My indices were great; however, I'm still fighting drowsiness even already this morning.  It appears to me that the pressure is still being driven by "flow limitations".  So, I'm optimistic the EERS will help.  Should I proceed to 13 tonight, with or without the EERS.

Also, I continue to struggle to understand what is meant by "pressure is driven by flow limits".  SR wrote:

11-16-2019, 08:07 AM
RE: Help refining CPAP settings to control Obstructive Events and Central Events/Are Cent
The situation is unchanged from what Bonjour said in his last post. Your pressure is driven by flow limitations, and that continues to be the case. While removing EPR has improved CA, you continue to have a very unbalanced inspiration/expiration time and flow limitation appears worse, and the flow rate chart has a "hair brush" appearance, especially on the lower (expiration) side. I look forward to Fred's input on this but my impression is that you are better off with EPR and that EERS is the better approach here, and you may tolerate even lower maximum pressure.
Sleeprider
Apnea Board Moderator
www.ApneaBoard.com

Emphasis added by Sherwoga

Could you expound on what SR means about the "hair brush" appearance. I've tried to add screen captures (using software other than the OSCAR F12 function) and have been unsuccessful.  But if you zoom in on the flow rate graph (assuming you can) to display about 1 minute segments in the time regions of 1) 00:06:00 to 00:07:00 and 2) 22:44:30 to 22:45:30, you will see two flow rate profiles that are very different.  Doing so might give you pictures to help me with my lack of understanding.

Also, I'm not sure the F12 screen capture of my data from last night worked.  I can't see the thumbnail or display the data from the Preview Post dialog.  Let me know if I should send the screen capture again separately.

[slowriter]

I continue to struggle to understand what is meant by "pressure is driven by flow limits". 

It's just that your breathing restriction is causing the machine to add more pressure.

The idea of the suggestions here is that you need EPR to reduce the FL, and you need EERS to ensure the CAs don't rise along with that.

So when you get the EERS setup, you want to start experimenting with raising the EPR to see what happens.

I'll let others suggest exactly what settings to start with.

[Sleeprider]

I'm fundamentally lazy, so I'd like to cross-reference a post I made to another user that is considering EERS:

http://www.apneaboard.com/forums/Thread-...#pid319934

This post summarized another user's experience, and how changes in machines, settings and EPR evetually led them to consider EERS to control the CA events that came with the Airsense 10 EPR (pressure support). I think the discussion is worth mentioning here, because you are both dealing with similar issues.

You asked what I meant about "hair brush" appearance of the flow rate.  This is a what the flow rate looks like when the inspriation and expiration flow rates vary from the average at a high rate.  We can only interpret the flow rate at a close zoom level that shows 2-minute segments. That lets us see the individual breaths, allowing us to see why the flow rate varies. Usually this "bristle" appearance is the result of flow limitations or upper airway resistance and recovery breaths.  In the following charts, this is especially noticeable at 22:30, 23:30, 01:15 and many other locations where obvious spike of flow above and below the normal are occurring, usually coinciding with higher flow limitation.  It is helpful to zoom into a section where this flow limitation is happening, and compare that to a section of normal respiration like we see at 01:40 or around midnight wher there is also a CA.  I suspect the take-away is that with no EPR, the flow limitation has more effect on your respiration and arousal rate, than if we add EPR and deal with some CA.  Ideally, we can use EERS to minimize both.

[JoeyWallaby]

If you share your raw data from your SD card as a .zip file, members will be able to inspect your results themselves (without you having to post a bunch of screenshots).

[sherwoga]

If you share your raw data from your SD card as a .zip file, members will be able to inspect your results themselves (without you having to post a bunch of screenshots).

JoeyWallaby,

Thanks for the tip.  I 

1. went to my directory (Windows 10 OS), 
   
2. found and opened the DATALOG sub folder, 
   
3. right clicked on the sub folder for yesterday's date, 
   
4. selected Send To, 
   
5. selected Compressed (zipped) Folder, and 
   
6. saved result back to DATALOG sub folder.  
   

Doing this generated a zipped sub folder that is of Size 1,405 KB.  Tried to attached same here and got an error message indicating that the attachment is too large (limit is 1024 KB).  Is there more I can do to compress it? Are there some of the individual files in the date's sub folder that can be excluded? 

Also, doing the same from the SD card itself actually gave me a slightly larger zipped folder.  

Sherwoga

[JoeyWallaby]

Copy everything from the SD card into a folder, put all of that into a .zip file. You can upload the resulting .zip file to any file-sharing website of your choice (mediafire or whatever) then share the download link.

[sherwoga]

Did this work?

https://www.dropbox.com/s/nmy1xz33vy0g8f...0.zip?dl=0

I'm attempting to use Dropbox.  Can you open the link?  If so, then I know it is working and can follow your tip.  Thanks for your help in advance.

Sherwoga

[Sleeprider]

We often use dropbox. There was no file in the linked folder.

[sherwoga]

We often use dropbox. There was no file in the linked folder.

I've had a dropbox account for a long time, but it's been multiple years since I've used it.  I seemed to have locked it up with my last attempt and can't even delete the file.  I'll keep trying, but will use PM to send links so as not to clutter up this thread more.  

sherwoga

[slowriter]

Keep in mind, though, that many of us (say me) won't bother to load those files, and would prefer a simple summary screenshot (per the instructions). You could obviously do both.