PLMS and UARS - settings help

[gregbe2000]

I've had several discoveries over the last 9 months after I started using OSCAR.  I was on an APAP of 5-8cm for last 5 years to treat moderate OSA.  The myair.com dashboard has continued to tell me I'm doing great and feeling great - though I've always felt miserable in the morning.

• Through OSCAR, I saw that I had consistent flow limitations - my flow rate was not rounded - flat peaked or M-peaked a lot of the time.  I assumed my recovery breaths were the result of inspiratory effort - as I could always find a flow restriction in the breaths leading up to them.  EPR 3 helped with this, but I couldn't get consistent rounded breaths.  I tried higher pressures with EPR of 3 but that didn't work - plus leaks and comfort were compromised.  I switched to a Bipap and with pressure support of only 3 with epap of 7cm I was able to get consistent rounded peaks.  I was hopeful, still am, that this will lead to less arousals but it's possible that flow limitations are a red herring and this isn't what is leading me to arousals (more on this later).
  
• I had always gotten CA clusters that were falsely flagged as CSRs - only in 2nd half of the night or whenever I was between sleep and wake.  I learned through OSCAR and a video camera that this would be most pronounced when I was on my back - so now I wear a vest with a ball in the back.  The CA clusters were minimized when I thought a static pressure with no EPR was best for me (before I discovered the flow limitations).  Once I introduced the bipap these clusters starting getting larger (only on some nights).  If I'm ever between awake and sleep I'll reel off a series of 10-30 CAs in a row - a chart of this is below.  I don't know what is going on, but I'm guessing I have an arousal (or I'm slightly awake for some reason), and I hold my breath and this kicks off the waxing and waning and CAs due to an over-sensitivity of CO2 (high loop gain?).  It only occurs in 2nd half of the night.  This typically destroys that last 2 hours of my "sleep".  I don't know how to fix it.
  
• Every night I'd see patterns on OSCAR that looked like choppy flow - I thought this was a bunch of recovery breaths due to flow limitations - but that was wrong.  After reviewing the video of my night it became clear that I have PLMS.  My movements in one PLMS session are consistently spaced between 20 and 40 seconds (usually 23 seconds!).  I typically have 2-3 "sessions" of this per night that total between 60-90 minutes.  It is usually in the first half of the night.  My movement is rarely in my leg, it's either in my shoulder or hip.  I've had sleep studies that detected some PLMS but the sensors were always on my shin.  My PLMS has a respiratory flow signature as I have a slightly deeper breath on each movement. I can easily detect it right in OSCAR (see below chart). I assume this (greatly) hinders my sleep quality in the 1st half of the night - it's at least interfering with getting to or staying in a particular sleep stage.  I can go back through my CPAP data in OSCAR from 5 years ago and detect that it was present and significant from the start.  I don't think there is an effective way to deal with this without drugs, so I'm reluctantly starting gabapentin and will titrate up to some amount (not sure how much) to see if this works and if it makes me feel better.
  

Questions:
1) Suggestion on pressure/settings tweaks to minimize the sleep/wake CA clusters that seem to be worsened due to high loop gain (just guessing).  Maybe the pressure changes are exacerbating this issue so I'm trying to see how low an EPAP and pressure support I can go and still have good rounded flow (though not even sure if the non-rounded flow is impacting me).   I'll be trying 6cm EPAP and 9cm IPAP tonight.  I have trigger setting of High.  I'm using Easy-Breathe setting but does it make sense to change this and modify rise time to be longer and consistent (to have a more gradual pressure change from EPAP to IPAP)?
2) Does anyone have experience on ways to mitigate PLMS without drugs?  I tried Mg, but only for a few days.
3) If someone here has PLMS and tried is or on gabapentin - at what level did you have to take to see an impact?

If anyone has any insights into anything I mentioned, please chime in.  Thank You!

   
   
   

[Sleeprider]

For the CA clusters change your trigger sensitivity to very-high. I think turn down IPAP to 10.0 which will be PS 3. We really would benefit from the flow limitation statistic, so change to Vauto mode with EPAP min 7.0, Max Pressure 11.0 and PS 3 with very-high trigger. This will allow flow limits to show, which are the important statistic for UARS. You have some periodic breathing with CA events, so we need to find a sweet spot where we can resolve the flow limitation from UARS and not wash out the CO2.

[gregbe2000]

Thank you Sleeprider!  The picture I showed in the previous message was from a few nights ago.  The ones below are from last night as I've been tweaking my pressure down with the hope of minimizing the high loop gain impact at the end of the night.  Last night I was at 6cm EPAP and 8.2cm IPAP (2.2cm PS).  Even at this epap and ps, I think my flow looks pretty good (a sample is below) and I didn't notice recovery breaths as a result of on obvious flow limitation.  Given this, do you recommend I stick with 6cm min EPAP and 8.2 cm max IPAP and just change trigger to very high?  I can change from S to Vauto with these settings and I think my FL will show. I had gone from Vauto to S because I thought any additional changes in pressure could exacerbate my CO2 sensitivity issues.  Do I have this wrong?

I did use the settings of EPAP min of 7 and max IPAP of 11 with PS of 3 in Vauto last week.  The trigger was high.  The 95% flow limit as this setting was 0.00 (I'm not sure if this is considered a credible metric or not).  I've attached the whole night screenshot of this night at the last chart.  Thanks again.

   
   
   

[Sleeprider]

Yes to your questions. You are right in-line with my thoughts on this. Nice improvement with lower pressure and PS.

[gregbe2000]

Hi Sleeprider, 

I think changing from high to very high trigger has really helped minimize my CAs as I've had 3 nights in a row with next to no CAs.  It could have been due to lowering PS from 3.0 to 2.2 but I doubt it.  I raised PS to 2.4 last night and had zero CAs.  I think I could go back to PS of 3.0 and I'd still have very few CAs, but haven't tried that yet.  I'm still getting periods of unstable breathing (waxing and waning for fairly long periods) - I've attached a chart of that.  Without the very high trigger I would stop breathing at each cycle and rack up a large cluster of CAs. Also, I think most of the hypopneas that are flagged would have been flagged CAs if the trigger wasn't very high.  

Questions:
1) Apart from fixing whatever arousal kicks these off (it could just be a normal awakening), are there any settings options to further mitigate the waxing and waning?  I'm assuming this leads to poorer quality sleep and I'd benefit from eliminating it.  I heard there is a drug that lowers CO2 sensitivity, but I'd like to avoid another drug.  I'm currently early on in an gabapentin trial to see if it helps with my PLMS.
2) The FL has 0.01 at 95% and 0.22 at 99.5%.  This seems like very low FL.  I still count about 15% of my breaths have some flow limitiation when i estimate it in 1st and 2nd half of night samples.  I assume I'd benefit from raising PS more if it doesn't impact CAs?  What do you think?

Thanks for your help!