Lower EPR Higher Hypopneas
My AHI numbers are pretty good, including the odd <1 though this is infrequent. Over the last few months my major events have been CAs and as I had an EPR setting of 2, I wondered if I was getting some CO2 washout. So last week I dropped it to 1 and this didn't affect my sleep comfort. I got to sleep just as quickly and either had one bathroom stop or slept right through the night.
My CAs have gone right down but my Hs have gone right up. I also don't feel as if I got the sleep quality that I normally get. It's not a significant loss but I have noticed it.
So could a lower EPR cause this? Is this normal? Should I increase my lower pressure level (from 10 to 11) to compensate? Has anyone else noticed this effect?
RE: Lower EPR Higher Hypopneas
That doesn't make sense if they're obstructive hypopneas, but maybe they're central? What does the flow chart look like - do you have the big recovery breath typical of an obstructive event, or is it a smooth resumption? (I know it's often hard to tell with hypopneas). If your total number of events is small it might just be "static".
RE: Lower EPR Higher Hypopneas
EPAP level takes care of obstructive apneas. Pressure support on top of EPAP takes care of hypopneas. But higher PS also may increase CAs by excess co2 washout.
In resmed machines EPR x = pressure support of x cm h2o.
So reducing EPR may add to hypopneas and reduce CAs
And vice-versa.
So it's a trade off between the two. And the barometer to decide is: how do you feel in the morning and during the day on different settings.
PRS1 Auto & Dreamstation Auto w/ P10 and straight pressure of 8cm
RE: Lower EPR Higher Hypopneas
Did your 90-95% pressure change? Just curious.
RE: Lower EPR Higher Hypopneas
Interesting question. No, it fluctuates between 11 and 13 and has done for quite while now. I might raise the EPR again. I'm wondering if raising the min pressure to 11 might change some results. That said, I'm always well under 5.0 AHI but I'd love to go under 1.0
As I said in a previous post, I took advantage of the great price on the Remstar PR S1 series 60 Autoset and this will be with me in less than two weeks. Maybe I should just go back to an EPR of 2 and then look at what the Remstar does for me.
RE: Lower EPR Higher Hypopneas
I will be very interested to hear what you have to say about the PR algorithm vs. the ResMed one.
