Is CA event in PR System One a common pattern?

[apneo]

I was diagnosed to have hypopnea during the sleep study. However, based on the data collected last night by my CPAP machine, I am now
wondering if besides hypopnea I may have also Central Apnea. Just dont know how reliable the PR System One analysis is and whether these "CA"= Clear Airway Apnea signs, which seem to be associated with Central Apnea, are common patterns seen in people with Obstructive Apnea or Hypopnea. Does anybody see these "CA" patterns as well in their waveforms?

Here are my waveforms for the period in question last night. The graphs are consecutive

[apneo]

Here is the complete waveform report for Sat 4-30-11:

The weird part of the waveform (which I questions about) is in page 7, at around 5:53-6:11AM. There you see several CAs and periodic breathing. Is this an indication of Central Apnea or this is a common pattern during the night for people with Obstructive Apnea or hypopnea?

[TooGroggy]

When I first saw your post I couldn't think of what CA was. It turns out, according to this thread viewtopic/t47953/Clear-Airway-Apnea--Central-Apnea.html, that CA is nothing more than Respironics' name for central apnea.

You'll find quite a bit of discussion on central events on this site. The general thought is that pressure that is set too high tends to generate central apnea events (whereas pressure set too low tends to not prevent obstructive apnea events).

[apneo]

Thanks for the replies, TooGroggy and Pugsy.

I went back and edited my prior posts in this thread to avoid the confusion around the acronym CA. As the post TooGroggy suggested mentions, Respironics terminology distinguishes the Clear Airway events (CA) from Hypopnea or Obstructive Apnea since the device tests with a pressure pulse after about 6 seconds from the start of the event and the pressure sensor picks up the pulse, so the machine concludes that the airway is not obstructed. Respironics then associates this pattern with Central Apnea.

For the PR System One users in the community, here is a very useful link that describes how the machine operates and reports

https://knowhow.webex.com/ec0605lc/even ... rmat=short

[Pugsy]

I don't understand most of what I know about the waveform stuff yet.
An occasional episode of Periodic breathing is something a lot of us see (myself included). Occasional CA events are also common. Some can be sleep onset centrals, turning over in bed centrals or just a rare central. We don't have the added input that comes with a full PSG study to see just how critical these centrals really are.

What was the numerical break down for the AHI event indexes on those nights in question?
What pressure is being used? Were there any history of centrals during your sleep studies?

Posting of the daily detail report for one of those nights might offer a bit more insight than just the waveform data.

[apneo]

The PSG that was conducted a few months ago mentioned only hypopnea, but no central or obstructive apnea

On the other hand, here is what the CPAP summary report shows for Saturday night (4-30-11):


It says: 349 minutes at pressure of 10 (or around 90% of the night), 15 minutes at greater than 10 but less or equal than 12, and 30 min at pressure of 8 (ie. ramp)

At pressure of 10 this is what happened:
AHI = 2.1 events per hour = 1.4 Clear Airway + 0.7 Hypopnea + 0.0 Obstructive Apnea

At pressure of 8, AHI was 2.0 = 2.0 Hypopnea + 0.0 Hypopnea + 0.0 Obstructive Apnea

Which makes me conclude (with the caveat of not having a whole lot of data) that the CPAP pressure settings the sleep study recommended are correct. We see here the trade-off TooGroggy mentioned between obstructive events at lower pressures, and starting to see Central events at higher ones

[Hawthorne]

Having used a Respironics M Series before I got the PR System One, I note from my data, that the System One shows more CAs.The M Series did not. With your CA being 1.4 of your AHI, you don't need to be concerned, if this is about all you have any given night. An AHI of 2.1 is very good.

As Pugsy said, the CA can be recorded by the System One when a person rolls over or when they are just going to sleep (sleep onset) or randomly during the night. The "Daily Details" page of your daily data will show you when you are having these CAs.

[Pugsy]

viewtopic/t63464/Bragging-rights-thread ... ments.html

Please look at my first post in the above thread. It is a "daily detail" that shows when the CA events are happening in one of my nights. I had 3. One at the very onset of sleep (most likely sleep onset CA event), second one about 90 minutes into sleep, either a turning over in sleep or real central, and final one right when I turned machine off and I bet I was partially awake so that one can be tossed out also. Only the random one at the 90 minute marker is of any consequence and since only one of them I am not concerned. Some nights I might have a handful more of the CA events but overall not many especially if I can disregard probably sleep onset or awakening ones.

I am with Hawthorne. I wouldn't be concerned with that Clear airway index unless there were many more of them and when looking at the daily detail time line, couldn't be explained away.