Does EPR truly lower Central Apnea?

[RES9372]

I ask this because I greatly prefer to have the EPR set to 3, but my doc says to lower it to 1 to reduce CA. I haven't noticed any difference in the CA so far, and highly prefer the EPR at 3 to prevent aerophagia.

[Julie]

Not sure what your MD is thinking, but if you feel better with EPR at 3, then use it til further notice, tho' I don't know that it will help CA as you'd need a particular type of machine - regular Cpap won't address it.

Why not post a couple of Oscar nights so we can see what's what and possibly advise then.

[Pugsy]

Actually reducing EPR can reduce central apneas in some people in some situations but it isn't set in stone and sure doesn't apply to the majority of cpap users.

In some people using EPR can trigger an unwanted number of central apneas,,,,,,it can but it doesn't for all people.
Actually it is very, very small number of people that can have this problem with unwanted centrals.
Now if someone happens to be one of that very small number of cpap users where EPR causes a problem the most common thing to try is simply reducing or eliminating EPR.

So the doctors give it a try and see what happens.

Sometimes someone might have a problem with EPR at 3 in terms of unwanted central apneas but maybe EPR at 2 or 1 doesn't trigger the centrals.
Sometimes EPR isn't the trigger at all and even turning EPR totally off won't reduce the number of centrals. Depending on the number of centrals a different type of machine is needed to deal with the central apneas as well as the obstructive apneas.

Now if you had too many centrals during the diagnostic sleep study then using EPR isn't going to help because EPR isn't causing the centrals. You had them without even using cpap/EPR. Talk to your doctor to find out what all his plan of attack is for reducing central apneas.

[Miss Emerita]

I looked at your earlier posts and was reminded that you did have a lot of CAs at one point. Please do post a recent and typical Oscar chart so we can see what things look like now.

[ozij]

My CA during my sleep study was around 16 if I'm reading it right and was done at home in altitude - They stated I had primarily OSA, with a strong central component. Their recommendation was to start with an Auto PAP and possibly do a titration study.

Ugh! I'm out of ideas at this point and think you should get back in touch with your sleep doctor to report on your difficulties with central apnea. You might ask for an in-lab titration using PAP/bilevel/ASV settings to see what will actually work for you.

Did the titration study ever take place? if no, why not?
Has your doctor viewed your charts?
With a Central Apneda index of 16.1 during the sleep study, and a continuing problem with central apneas on PAP therapy fiddling around with an APAP and its settings look like a waste of time to me.

The issue is not whether or not EPR truly lowers central apnea. That's theoretical. The issue is what is necessary to figure out the best therapy for one person (you) with their specific sleep study results. If you are one of the few described by Pugsy, what applies to the majority does not applie to you. You've spent enough time on that AutoPAP trial.

A titration study is one in which all the know parameters of your sleep are monitored, and a qualified sleep technician set up different machine modes to see which type of Positive Air Pressure mode will normalize your breathing when you're asleep. This it what you need now.

[RES9372]

Thank you everyone for the replies! The titration study would be ideal, but unfortunately it was around $2000 and we aren't ready to explore that yet. The doc also said the ASV machine is extremely expensive. When she pulled my data she stated my average AHI was around 7, and that if I am typically under 5 when I'm at sea level, then everything is mostly fine and there isn't a need to pursue ASV at this time. I will be moving in a few months from high altitude to sea level and I've noticed when I'm at sea level my AHI tends to be under 5.

What's odd about all of this is I've had weeks recently where my AHI is consistently under 5, even at altitude. Then I have weeks like shown below where things get out of hand again. The only correlation I've noticed is that my AHI is much higher when I'm sleeping alone. When I'm with my fiancee, my AHI is typically under 5, even at altitude.

I keep reading about Flow Limit, do I have any issues there?

Ultimately I'm looking at maybe going back to an APAP setting, but any advice is appreciated. Thanks!

[LSAT]

Fixed pressure at 4? EPR is useless with pressure that low.

[ozij]

I ask this because I greatly prefer to have the EPR set to 3, but my doc says to lower it to 1 to reduce CA. I haven't noticed any difference in the CA so far, and highly prefer the EPR at 3 to prevent aerophagia.

EPR at 1 2 or 3 does nothing when your fixed pressure is 4.

The machine can't go lower than 4, and EPR is whatever you subtract from you inhale pressure, be it fixed or automatic.

Is your doctor aware of the pressure you're at?

[Deborah K.]

Most adults would feel air starved with a setting of 4. If I were you I would raise the pressure to 7 and see what happens.

[RES9372]

I definitely feel silly for not knowing the EPR wouldn't do anything at a pressure of 4. The reason for the low pressures is to see if lowering the pressure would lower the CA. I don't seem to have much OA, so I wanted to see how much we could lower the CA. After reviewing the data, I decided to go back to an APAP range with a higher minimum and a lower max - 5 min and 9.2 max. So far the results have been excellent on the first night. I took the mask off in the middle of the night, but overall I'm pleased with the AHI.

[Miss Emerita]

Don't feel silly -- if we all already knew everything, we'd never get to learn anything!

CAs can be quite variable from one night to the next, so don't be discouraged if they tick back up some.

I'm willing to bet those first three CAs, and maybe several more of the early ones, occurred while you were still awake, meaning that you should mentally bracket them. So your results are better than the numbers might suggest.

Your numbers for flow limitations are also better, probably because you're getting some EPR. (It'd be great if you could fit your FL graph into your screen shot. To make room, grab the gray bars that separate the graphs and push up on them a little.)

My advice would be to stick with your current settings for another few nights. If nothing weird happens, then I'd recommend raising your minimum to 6 so that you can get your EPR of 2 all night long. After that, depending on how things go, some additional fine-tuning might be in order.

[RES9372]

I just uploaded last night's data with the FL showing better - thanks for the tip! AHI got cropped out, but it was at 6.6. I'll be traveling to sea level this week and interested to see what it is at a lower altitude.

Regarding the EPR, I currently have it set to 3 and I had some questions on that - if my EPR is set to 3, will it not kick in until the APAP hits a pressure of 7? If the pressure hits 6, will an EPR of 2 kick in? Or how exactly does this work? Thanks!

[Pugsy]

Regarding the EPR, I currently have it set to 3 and I had some questions on that - if my EPR is set to 3, will it not kick in until the APAP hits a pressure of 7? If the pressure hits 6, will an EPR of 2 kick in? Or how exactly does this work? Thanks!

If your EPR is set to 3 then you need the 7 cm minimum to get the full 3 cm drop but if the pressure reaches 6 you would still get a 2 cm drop or if it were to reach 5 minimum then you would get a 1 cm drop.
Just remember it can't go below 4 cm pressure when it drops.

Essentially you get the amount of reduction available within the constraints of the machine itself.
You don't have to be using the 7 cm to get any exhale reduction...it's just you have to be using at least 7 to get the full 3 cm drop.
If using 7 cm minimum and setting of 3 EPR then you can get the full 3 cm drop
If using 6 cm minimum and setting of 3 EPR then you will only get a 2 cm drop while at 6 cm.
If using 5 cm minimum and setting of 3 EPR then you will only get a 1 cm drop while at 5 cm.
And when the machine is a 4 cm...no drop at all because it can't go below for even if set to 3 EPR.

[ozij]

Essentially you get the amount of reduction available within the constraints of the machine itself.
You don't have to be using the 7 cm to get any exhale reduction...it's just you have to be using at least 7 to get the full 3 cm drop.
If using 7 cm minimum and setting of 3 EPR then you can get the full 3 cm drop
If using 6 cm minimum and setting of 3 EPR then you will only get a 2 cm drop while at 6 cm.
If using 5 cm minimum and setting of 3 EPR then you will only get a 1 cm drop while at 5 cm.

Something I don't understand:
When using EPR at higher pressures, I get a red line for IPAP in the Pressure chart, and a green one for the EPAP, the green line being an EPR's distance below the red.

RES9372 has EPR set to 3, full time. The Pressure chart only shows a minimal blip of a green EPAP line at about 06:15, when she reaches IPAP 7.

Why no EPAP line when she's at less than 7, and EPR is presumably functioning at less than 3? Is that an OSCAR issue?

[Pugsy]

Why no EPAP line when she's at less than 7, and EPR is presumably functioning at less than 3? Is that an OSCAR issue?

I don't know.
EPAP could be at 4 cm so we can't see the green EPAP line when it is on the baseline number. I think that is probably why we can't "see" it...but it's probably there at the baseline.
But obviously there are times where EPR can kick in but we don't see it in action at these settings.

I can't explain it.

I would need to compare a ResScan report to an OSCAR report to see if it was maybe just an OSCAR issue.
All I know is that when I was using my bilevel auto with EPAP min set to 4 and PS set to 4 that I never saw an EPAP green line until the pressure started to climb a bit.