CAs recorded by CPAP

[Art10630]

I had my titration last night, and I received my new CPAP (Dreamstation Auto) this morning. Didn't get a ton of sleep last night, so I decided to take a nap this morning and give my new machine a whirl. When I woke up, I of course imported my data into SleepyHead, and I was a little surprised to see how much action the CPAP picked up.

My initial study recorded an AHI of 2.8 and an RDI of 12 (so most of my events were RERAs, not actual apneas/hypopneas). There were no Central Apneas recorded. During my titration, the tech said that I had no Apneas/Hypopneas, but that she was still seeing some RERAs while she was trying to find the right levels. So, when I looked at my post-nap data, I was surprised to see 3 "Clear Airways" (is that the equivalent of a Central Apnea, or something else?) recorded right after I fell asleep (see screenshot below). Are these really CAs, or could this be something else? I'm not really concerned at this point, since this is based on an hour and a half of data, but I'm trying to understand what exactly I'm looking at so I can continue to monitor things over the next few weeks before my follow-up. Thanks!



*Oh, and the AHI shown is a little misleading, since I was awake for several scoring events (I was experimenting with the machine). In reality, I had 4 Hyp, 1 RERA, and 3 CAs, and 1 Flow limitation in about an hour and 15 minutes that I was actually asleep.

[Julie]

What you saw is normal - a few CA's (central, or clear airway) just as you fall asleep and very possibly just before waking up. Some people call it 'sleep wake junk'! It's nothing to worry about at all and only if you start seeing lots of them throughout the night or in clusters should you be concerned.

[ChicagoGranny]

"Clear Airways" (is that the equivalent of a Central Apnea, or something else?)

What is Clear Airway Apnea?

An apnea is detected when there is an 80% reduction in airflow from a baseline for at least 10 seconds if there is no airflow detected for 10 seconds. During the apnea, one or more pressure test pulses are delivered by the device. The device evaluates the response of the patient to the test pulse(s) and assesses whether the apnea has occurred while the patient has a clear airway or an obstructed airway. The airway is determined to be clear if the pressure test pulse generates a significant amount of flow; otherwise the airway is determined to be obstructed. When the airway is clear then a Clear Airway Apnea event is recorded.

https://www.mysleepmapper.com/Help/Faq#

[LSAT]

What you saw is normal - a few CA's (central, or clear airway) just as you fall asleep and very possibly just before waking up. Some people call it 'sleep wake junk'! It's nothing to worry about at all and only if you start seeing lots of them throughout the night or in clusters should you be concerned.

+1

[Art10630]

Thanks! One more question - how does PR Dreamstation Auto account for naps? I took a nap this morning (really to get the rest of the 8 hours I typically get, since the titration threw off my schedule), and then another short nap this afternoon like normal. On my CPAP, Dream Mapper, and in SH, these two naps were recorded as two separate days - one on 8/7, and one on 8/8. I didn't even have the machine on 8/7! Is there a setting that's weird (I confirmed that the times are correct on the machine, and they match the recording times in my apps). My insurance is really picky about compliance, and right now it looks like I'm not compliant even though I've already slept 4 hours today in naps.

Thanks!

[Pugsy]

A new day with the Respironics machines will start at noon GMT time. It goes for 24 hours and then at noon GMT time the next day a "new" day will start in terms of recording. So naps may seem to mess up the recording a bit in terms of usage but in the long run it all works out.
Now if you live in an area where you are actually asleep when non GMT times rolls around that sleep session isn't broken up but any new sessions will be on the next day's calendar date.
It can be frustrating trying to make sense of the Respironics clock unless a person lives in the UK where their time is GMT. It's all based on 24 hours though and GMT is the line it goes by no matter where you live.

If you live on the west coast it is very possible that the morning nap you had this morning was still before Noon GMT time and thus it will reflect yesterday's date.

[Art10630]

Got it! I just wanted to make sure it wasn't going to do something weird tonight. I didn't notice in my original screenshot that my first nap came up as 7/7, so I think you've explained it! Thanks!

[Art10630]

One more question - my CPAP is over-counting events (which I understand is pretty common), so I'm trying to look through and understand what is and is not actually an event. Here's something that was marked as an apnea last night:



Is this actually an apnea as far as we can tell without oximetry? I think it meets the 10s threshold (or is really close), but I'm not so sure what that big wave is in front and if that suggests that this isn't real.

[Jay Aitchsee]

viewtopic.php?f=1&t=112345#p1080291

Well, since it's been hijacked....

edit II: Ron, I thought you might like this graphic: I've chosen to use CA here, but it could also apply to OA. Note that I have said "likely" in the legend.