Still extremely tired after almost 4 years of Bipap

[topdba7]

Thank you! wonder if this is what you want to see:

[DaveSkvn]

Thanks for that. The first two graphs don't seem to have any issues. The third indicates something unusual.

If you have a look at the first two graphs, the part of the "flow rate" above the dotted line (the inspiration / breathing in part) looks like half an egg. Each breath looks much the same. That is good. In the third graph the breaths start with the "half egg" (good) and then are longer and flatter (bad). "Flatter inspiration curve" often means the airway is partially obstructed and the flow can't get above some value. Whilst the flow limitation is shown as zero, the red line in the pressure graph is starting to rise so the machine has spotted something is wrong and is ramping up the pressure but perhaps a bit too late to stop you being "woken" in some way.

   

Are you familiar with UARS (https://www.youtube.com/watch?v=sa9zNYpTWlM)? I've got OSA (it turns out, on my back mainly) but I suspect 80% of my problem is UARS. Your neck/nose airway is reduced and you end up badly rested/sleepy during the day but (a) your SpO2 is just fine at all times and (b) your breathing never reduces to zero so its much more difficult to spot in a sleep study.

I've never been near BiLevel so I'll leave advice on that to @staceyburke but it is possible that, just like my positional apnea, your issue (be it UARS or other) won't respond to pressure therapy. Mine didn't. In the last two weeks I've found significant benefit from (a) a soft foam neck brace (£5 off ebay) and (b) an improvised "slumberbump"  (based on a £5 shoulder brace, a towel and some string) to keep me off my back. Both are low cost and would be worth a try. It might also be worth getting a $30 infrared web cam off the internet, record yourself sleeping and see if the "flow limitations" being detected by your machine are related to any position.

Now the awkward bit. CPAP machines, sleep studies and sleep clinics are all set up for OSA - its much easier to spot than UARS. I've just started trying to trudge through the Resmed APAP patent. Its all about OSA (which is fair enough and very useful). If your issue is UARS (or similar) a CPAP/BiLevel machine is not really designed to manage your condition. Its not looking for signs of "steady state" flat inspiration curves - it can but it chooses not to - its not what it is intended for. Fairly major "flat inspiration curves"/restricted breathing might only get a small bump on the "flow limitation" graph.

If you want we can have a look at some other events from last night. Remove the scaling from the "flow limit" graph (it was the wrong graph, oops). Look for the small bumps and then zoom in on the "flow rate" graph above for 60 secs with the scale set.

[topdba7]

Thank you so much David! Your assessment makes total sense. I found myself wake up every time when I was in a REM (remembering dreams) when muscles relax and needs more pressure support. I have been using soft collar already, also tape my mouth to prevent air leak. I have always slept on my back because of my neck misalignment (might take quite some time to fully recover) prevents me from using any other sleep positions. I wonder if ASV is a possible solution for me as I read stories that some people have successes on using ASV for their UARS. I have attached 2 more charts for you to exam for me.

Thanks again,

[DaveSkvn]

The plots aren't zoomed in but the second doesn't look too bad. There are egg shapes above the line though not exactly regular. The first one is not good. It reminds me a bit of my UARS state before I put the collar on.

   

As you can see the red circles (exhalations) are about 5 secs apart like normal but there is a lot of panting in between - it was recorded by CPAP as over 40 breaths a minute but with a flow limitation of 0.04 out of 1 (i.e. nothing to see here). On your trace the panting/gasping around 01:41:55 and 01:42:20 seem a lot like the desperate breathing mentioned in the UARS video and is definitely not normal restful sleep. You would eventually get enough oxygen so there will be no visible SpO2 impact. The algorithm won't see it as a hypopnea so it won't be visible on the AHI.

I only noticed it after I posted the reply earlier but if you look at the pressure graph in the original image under the label "system change" at 04:54:12 there is a very slight drop in the pressure line. It seems that very slight drop in the pressure meant something in your neck/nose dropped into place and partially blocked the airway. It was exactly at that point that your breathing went from good to bad. The machine did detect it and then ramped the pressure up but you'd probably been partially woken (who knows what pressure would be required to get it out the way again). It does however mean your machine and its pressure is helping. I would say that as the machines are set up to detect and respond to OSA events, and this is not an OSA event, I personally would not trust the auto algorithm to spot and respond to your issue. It might be better if you use fixed settings - as high as you can tolerate comfortably. On ASV, I'm afraid I'm no help at all.

[topdba7]

Thank you Dave. Do you think it is a good idea to set Min EPAP to 9.4 (last night’s max was 9.33) and increase the PS to 5 from 4 would help alleviate the flow limitation?

[DaveSkvn]

As I say, I have no experience of bilevel myself and would defer to @staceyburke.

From my understanding, I would go for a base level (EPAP?) of min 9.0 (or 9.4 - not much in it). With PS of 4 that means IPAP would be 13 - which is where your aerophagia kicks in (same as me) - so PS can't really be above 4.

You can leave the Max EPAP where it is and see if you are woken up with swallowed air much in the night. From your graphs it appears the machine doesn't often stray above that base level (9 + 4 = 13). If you are woken up, the "max EPAP" will have to be reduced until it stops.

I'm new to this advice game but my understanding is that your "aerophagia limit" is a result of your physiology and can't be influenced much. A limit of 13 is quite low and will limit the pressures you can use. My limit is also about 13 and I originally had an auto machine with max 16 - lots of midnight wakenings.

Give it a go tonight and report back tomorrow...

[topdba7]

Thank you Dave! Will report back tomorrow morning trying tonight with Min EPAP 9, PS 4, and Max IPAP 15.

[topdba7]

This chart is from last night's sleep record. I still waked up numerous times.

[DaveSkvn]

There are still flow limitations being detected. The pressure is still being pushed up several times through the night. I take it you were awake with the machine on from 01:40 until 03:20 when it all started again.

The good news is the pressure is not being pushed up by much - and it seems to settle things down when it is raised. Did you have many problems with swallowing air / too much pressure during the night?

If you feel able, I think it would be worth trying

min EPAP 9
PS 5

We're looking to see an empty flow limitation box and flat lines in the pressure box. If we get that you can hold settings for a few nights and see if the wakenings become less of an issue as you get used to the pressure.

[topdba7]

Hi Dave,

Happy New Year!

You're absolutely right. I woke up at 1:40 a.m., got up and worked for about 20 minutes, then went back to bed. I’m not sure exactly when I fell asleep again. I felt okay with the pressure above 13, though I experienced some mild aerophagia.
I’ll definitely try your suggestion: Min EPAP 9, PS 5, and Max IPAP 15 tonight.
I usually have nasal congestion when lying down due to a deviated septum and enlarged turbinate, which my ENT doctor has diagnosed. I've been considering surgery to correct the septum, but I'm hesitant because I’m concerned about the risk of empty nose syndrome if the turbinate reduction doesn’t go well. My nose works fine when I'm upright, so I wonder if the congestion could be related to the BiPAP air pressure.