Flow Limits, RERAs and CA events

[RadarRalfs]

Hello All,

I am on day 26 of continuous APAP.  On Apr 4th I began a thread on Cheyne-Stokes which Gideon and others helped with.  In that thread Gideon also suggested that my "Flow Limits" were a bit high and I might better control them by changing EPR from 1 to 2.  He also explained that CA events are "consistently inconsistent" but could be related to low CO2 levels caused by the therapy, in which case, they should hopefully settle down in a month or two.  I thought it best to start a new thread as this is no longer about Cheyne-Stokes.

The current machine settings virtually eliminated the OSA events which is great.  It varies and is subjective, but I think I am feeling somewhat better as treatment progresses.  I have less brain fog in the morning but I still benefit from a 15 minute powernap in the late afternoon.  The flow limits, RERAs, and CA events remain perplexing.  I assume they prevent me feeling fully refreshed after sleeping.  In addition to wanting to feel more refreshed I also want to minimize any disordered sleep issues which may affect atrial fibrillation.  I was diagnosed with that last October and which led to being tested for sleep apnea.

I have done some reading and am getting a better understanding.  The following links have been helpful.

http://www.apneaboard.com/wiki/index.php...8Resmed.29
http://www.apneaboard.com/wiki/index.php...tion_Graph
http://www.apneaboard.com/forums/Thread-...flow+limit

I have attached screenshots of last night which shows higher flow limits leading to a RERA, after which the flow limits are much reduced.  What is causing the flow limit in the first place?

Also, here are my CA numbers for the last 8 days since setting EPR at 2.  I assume this is par for the course?

Date    Count
05-Apr    8
06-Apr    18
07-Apr    27
08-Apr    7
09-Apr    15
10-Apr    5
11-Apr    9
12-Apr    15
Average Duration: 22 sec.

Thanks in advance for any feedback.

[SarcasticDave94]

Some homework that may help you out. The OSCAR charts look good, however it depends on how you feel. Are you feeling any benefits, well rested or not? Great therapy must include not only good looking charts, but that you feel better for using it. Consider writing down comments on whether or not your feeling better for it.

PS it would be helpful to attach the OSCAR screenshots via the forum New Attachment: Choose File. This way we view your data without need to download.

[RadarRalfs]

Thanks.  I have been using the OSCAR Notes and Feeling feature.  But apart from the "Zombie" and "Awesome" endpoints, the middle ground seems subjective.  I am hoping for a gradual improvement.

Did not know about the "New Attachment" forum - I will use that in the future.

My stated CA average duration of 22 was a typo.  It is actually 12 seconds.

Still wondering about the higher flow limits leading to a RERA, after which the flow limits are much reduced.

Regards,
Dave

[SarcasticDave94]

Flow limits themselves can cause issues. Are you using EPR? I'm thinking you're on the AutoSet. EPR can combat FL. And it's OK on the attachment thing, that's what guys like me are for, to help in the Apnea and forum chaos.

[Gideon]

The first CA in your detail is an actual CA event.
The second CA in your detail is an arousal followed by you likely holding your breath.

The RERA detail is a pretty good RERA.

Here is the deal.  You need to balance your treatment by how you feel.
Treatment for flow limits and RERAs is exactly the opposite of what we do to minimize your central apnea.   Thus you face a balancing act that is mostly controlled by your EPR.

You lower EPR (even to zero) to favor minimizing the central apneas.
You raise EPR to favor minimizing flow limits and RERAs.

This means if you lower EPR to decrease the CA, you raise the flow limits/RERAs
and if you raise EPR to decrease your flow limits you raise your flow limits and RERAs.

The solution if your CA doesn't clear up is to get an ASV which will treat both and you will carry a very low AHI.

So it is up to you in the meantime to determine which value of EPR subjectively "feels" better to you.

[RadarRalfs]

Thanks Gideon - that is helpful. I am still puzzled about how the flow limit is higher at the start of the night and then lowers significantly after the RERA.

I will leave the settings alone for a few weeks and monitor - apart from experimenting with a mask change. I have ordered a F&P Brevida Nasal Pillow Mask and hope to overcome mouth-breathing and congestion issues I had earlier. I notice there is a machine setting for Full Face or Pillow and wondered what difference that makes.

Dave

[Gideon]

You were 'nothered' by the flow limits In the RERA then tossed and reset your body to a better position.