Couple of questions about RERAs

[Mistertransistor]

I'm new to the board. I live near London, England, so I have a Philips Dreamstation provided by the National Health Service. I've been using it for about two months. My initial sleep study apparently showed an AHI of 17, but now using CPAP at 8 or 9 cmH2O I have got it down to less than two. However, I don't feel any better. I never was *really* sleepy, but I certainly don't feel good.

In addition to the basic Philips DreamMapper, I've got SleepyHead. This shows quite a lot of RERAs occurring, perhaps 20 - 40 per night, usually in bursts. I have a couple of questions about these that I hope someone can help with.

1. does SleepyHead get its event data, especially RERAs, from the CPAP machine, or does it calculate them itself? Its other event counts seem to agree pretty well with DreamMapper, but that does not show RERAs.

2. From my naive viewpoint, the RERAs often look puzzlingly like nothing at all. I can't post an image or a link because I'm a new member, but zooming the 'Flow rate' chart just shows a train of cycles with nothing special that I can see where the RERA is marked.


Can anyone explain these events?

Thanks
Andrew

[OpalRose]

To answer your questions:
1.  Yes, SleepyHead gets all event data from the Cpap machine.  

2.  See link:
http://www.apneaboard.com/wiki/index.php...ndex_(RDI)

Rera's are important even though they aren't counted in the AHI, as these events can and do disrupt sleep.  This is why you probably still don't feel good.
Rera's plus AHI = RDI

A slight adjustment in pressure usually knocks out Rera's and Flow Limitation.

[Mistertransistor]

Thanks OpalRose. I knew about RDI, but I'm still puzzled about a couple of things:

1. why does SleepyHead show lots of RERAs but I see nothing anomalous in the flow rate, unlike apneas which are obvious? Maybe I'm being naive here.

2. The hospital did a test of setting the Dreamstation in AUTO mode with flex, with an EPR of 3. I have subsequently repeated that at a slightly higher pressure with an EPR of 2. On both occasions the RERA count dropped a lot, but the clear airway apnea count increased significantly. That does not sound like a good trade to me, but again I may be missing something.

The machine auto-setting was originally 7 cmH2O but I have increased it to 9 without much effect on the RERAs. I'd really like to find out how to reduce them (without increasing the CAs!).

Andrew

[OpalRose]

The only way to really advise is to see your data from #SleepyHead.   We wouldn't want to see clear airways increase either.  

Just a clarification on Flex settings:  Flex does not drop pressure quite the same as EPR on ResMed machines.  The most drop (exhale relief pressure) you can receive with flex is up to 2cm no matter which setting of 1, 2 or 3 you use.  It is a matter of how it feels.  

Perhaps a better description:
You can receive up to 2cm pressure relief, but is flow based.
• C-Flex – Provides pressure relief upon exhalation.
• A-Flex/C-Flex+ – Provides pressure relief taking place at the end of inhalation and at the start of exhalation.


When you move from New Member to Member status, you will be able to post data.
In the meantime, follow the tutorials in my Signature Line and set up a free account on imgur to upload your Screenshots here.
Insert a space in the link and then we can figure it out.

[trish6hundred]

Hi Mistertransistor,
WELCOME! to the forum.!
Good luck with CPAP therapy,
hang in there for more responses to your post.

[Mosquitobait]

I can't answer most of your questions, but if you haven't gone to bed yet (I know it's about midnight there now), try increasing your pressure just .5. RERAs are eliminated by raising the bottom pressure just slightly. Doesn't usually take much but you need about 4-5 days at one pressure before you can tell whether it's working out or not.

[SnoringInOregon]

The machine auto-setting was originally 7 cmH2O but I have increased it to 9 without much effect on the RERAs.

Sounds like you've already tried the most obvious change.

My experience was unlike yours. It was more like the other poster who said "RERAs are eliminated by raising the bottom pressure just slightly". In my case when I went from min 7 to min 8 there was a dramatic drop in RERAs. They were cut in half or even better than that.

But I will warn you at least in my experience the number will vary quite a bit day by day. Here are my RERAs from the last few days. These aren't the actual number of events, it's the per hour result as reported by SleepyHead:

0.99
1.06
2.32
3.30
0.43
1.46
1.39
3.11
1.40
2.87
3.53

I wish i knew the secret of why they vary so much. And mine do often cluster just like you say yours do.

[Mistertransistor]

Thanks again OpalRose. Here's a link to an example of a RERA which I don't understand
http://wylie.org.uk/RERA.png  (that's my web site)
can you see why the machine says I have respiratory problems there?

I have exported my SleepyHead data and am now statistically analysing it using R. It has immediately shown another oddity that makes me further question the detection of RERAs by the Dreamstation:
 as I said above, when the hospital changed the machine mode from CPAP to AutoCPAPwithFlex, the CAs increased. Because I could not see RERAs at the time, I did not know that those had dropped a lot, and so I asked the hospital to set it back to fixed pressure CPAP. Now looking at the RERAs in SleepyHead I see the drop, but also that when the mode was set back, the RERA rate went back to one considerably higher than that at the beginning, even though the machine settings were identical. It has remained higher ever since (although all these rates do fluctuate a lot from day-to-day). If I believe that, five days on the AUTO mode substantially changed my symptoms.

Of course I don't believe that, and now I'm able to change the settings  myself, although I may get into trouble with the hospital for doing that.  Nevertheless I want to try the Auto mode at higher pressures, as it seemed to really reduce the pressure at all times: I noticed it immediately and my wife complained that I was making much more noise through my mouth. I'm trying that now, but I'll need a number of days of data to be sure that any effect is statistically significant.

Thanks to everyone who has responded.

Andrew

[OpalRose]

I see the clusters of Rera's, but it would be nice to see an entire screenshot of the daily page, as shown in the tutorial in my signature line.  This way, you can compare the pressure graph along with the events.  Look in #SleepyHead and see where your pressure was at the time of the Rera's, and compare with the flow and pressure graph.  

I'm a little confused, when you say you were using Cpap mode, you could see Rera's, but not in Apap mode.  I never used Cpap mode, but if I had Rera's, they showed up in Apap mode.  

The CA's may have increased because you were using the Flex feature.  

I think, and that's without seeing what pressure you were at when the clusters occurred, is that the pressure at the time was too low.   And I do agree that our machines may not be 100% accurate.

Again, if you would post that data from the Daily page and include the information as stated in the tutorials, we may be able to better advise.

Ideally, post a screenshot while using Cpap mode and a screenshot while using Apap mode.

[attachment=3878]

You may want to read some of the explanations in The Beginners Guide to SH.
http://www.apneaboard.com/wiki/index.php...Rate_graph

[PaulaO2]

I suggest you go through this to understand how to organize and post your screenshots.
http://www.apneaboard.com/wiki/index.php...ganization