Are Clear Airways CENTRAL APNEAS

[mon]

I'm just wondering whether the term CLEAR AIRWAY means Central Apneas. Does anyone know whether this is the case?

[SGearhart]

Yes they are the same. The difference is between what Resmed and Phillips-Respironics call the event of the brain forgetting to tell the body to breathe.

[Pugsy]

Respironics elected to call these open airway cessation of breathing Clear Airway events.
ResMed calls them Centrals.
SleepyHead was originally designed for Respironics machines so Clear Airway events stuck...If a person has a ResMed machine SleepyHead still calls these open airway cessation of breathing...Clear Airway but if ResScan is used these same events are called centrals.

[palerider]

Yes they are the same. The difference is between what Resmed and Phillips-Respironics call the event of the brain forgetting to tell the body to breathe.

yes.

[Jay Aitchsee]

But neither as scored by a home sleep machine may be a true "Central Apnea" as scored in a laboratory sleep study (PSG). To be a true central apnea, the patient must be asleep. Home machines have no way to tell whether the patient is awake or asleep. In the lab, it is done by EEG. It a patient rouses and stops breathing momentarily, like when rolling over for example, the home machine may score that as a CA or Central. A lab would not.

[archangle]

There are some questions about the accuracy of CPAP machines detecting "central apnea."

If you're awake, it doesn't "count" in a sleep test, but the CPAP machine doesn't know.

There are also some conditions where you may have a true central apnea, but the machine will still call it an obstructive apnea.

However, whether it says "clear airway" or "central apnea," it basically means the CPAP machine's best estimate is that it's a central apnea.

[BrooklynCPAPer]

Glad to see this topic! Thanks to the OP.

I looked at my past week's data in SleepyHead the other day and nearly all of the calculated AHI comes from these Clear Airway Apneas. It's never been mentioned on any in-lab sleep study so I'll make the assumption for now that these are false positives unless my sleep doctor is concerned with the pattern or thinks there is concern for ComplexSA emerging.

Oddly enough, last night I had one of my best sleeps since starting CPAP with an AHI of 2.2 (including Clear Airway) - and even odder I fell asleep with the machine on but also the light on. Hopefully the light on had nothing to do with it but it's an interesting note for my sleep log just the same.

[RogerSC]

Glad to see this topic! Thanks to the OP.

I looked at my past week's data in SleepyHead the other day and nearly all of the calculated AHI comes from these Clear Airway Apneas. It's never been mentioned on any in-lab sleep study so I'll make the assumption for now that these are false positives unless my sleep doctor is concerned with the pattern or thinks there is concern for ComplexSA emerging.

Oddly enough, last night I had one of my best sleeps since starting CPAP with an AHI of 2.2 (including Clear Airway) - and even odder I fell asleep with the machine on but also the light on. Hopefully the light on had nothing to do with it but it's an interesting note for my sleep log just the same. :)

Yes, a non-ASV cpap machine can't do anything about centrals. I'm in the same situation, no centrals in my sleep test, yet using cpap I have centrals. Not very many, my AHI is currently almost always under 2, sometimes under 1, but centrals are mostly what I see, as well, few OA's. My AHI last night was 1.9, all centrals. However, keep in mind that you don't see the OA's that the cpap machine prevented, only those that it didn't prevent. So it's really hard to know how many OA's you would have had if you weren't on cpap.

When I've asked my sleep doctor about these centrals, he basically says that I have too few to worry about. And mentions that they can be from something as normal as holding your breath while you roll over in bed (which I do quite a lot, the rolling over part, that is *smile*). He can't prescribe an ASV unless I have a lot more centrals (as you mention, complex apnea). Hard to tell if these centrals are "false positives" or not, and at the number that you and I are having them, it really doesn't matter one way or the other.

[archangle]

Glad to see this topic! Thanks to the OP.

I looked at my past week's data in SleepyHead the other day and nearly all of the calculated AHI comes from these Clear Airway Apneas. It's never been mentioned on any in-lab sleep study so I'll make the assumption for now that these are false positives unless my sleep doctor is concerned with the pattern or thinks there is concern for ComplexSA emerging.

In my opinion, false positive CA are rare except when you're awake. If you're seeing CA while you know you're asleep on an A10 machine, they're probably real.

[SGearhart]

I know some people that can go to sleep in mid sentence and then there's people, like me, that require at least 30 minutes to fall asleep. I've found that if you use the ramp feature on the Resmed. it won't record any events while it's in the Ramp mode. This allows me to get to sleep before it starts keeping score.

[Jay Aitchsee]

Glad to see this topic! Thanks to the OP.

I looked at my past week's data in SleepyHead the other day and nearly all of the calculated AHI comes from these Clear Airway Apneas. It's never been mentioned on any in-lab sleep study so I'll make the assumption for now that these are false positives unless my sleep doctor is concerned with the pattern or thinks there is concern for ComplexSA emerging.

In my opinion, false positive CA are rare except when you're awake. If you're seeing CA while you know you're asleep on an A10 machine, they're probably real.

Arch, how do you "know" you're awake? How do you "know" that you are not in a short period of arousal that you don't remember when the CA was scored? My position (see my post a few up) is that, unless you are being monitored by EEG, you can't know whether CA's scored by a home machine are "real" or not. Looking at the flow wave chart, I think one can make a good guess, but without special equipment, I don't see how anyone can "know".

[BrooklynCPAPer]

Arch, how do you "know" you're awake? How do you "know" that you are not in a short period of arousal that you don't remember when the CA was scored? My position (see my post a few up) is that, unless you are being monitored by EEG, you can't know whether CA's scored by a home machine are "real" or not. Looking at the flow wave chart, I think one can make a good guess, but without special equipment, I don't see how anyone can "know".

I'm curious what others think about this too - a lot of my Clear Airways tend to be clustered together and I'm a very active sleeper to say the least so it's totally plausible that I'm rolling about and the machine is registering it as CAs.

I'll circle back with what the sleep doc says after Tuesday when I show him the data for the past month in case it's useful for someone else or the OP.

[Pugsy]

Don't forget that some centrals are simply normal to experience anyway and don't mean something bad is happening...
like a sleep onset central and that doesn't limit itself to the first of the night because we often have brief arousals or mini awakenings during the night (that we may or may not remember) and with each arousal there can be a new sleep onset stage transition and thus another chance for another central to happen. They are "real" but considered a not so unusual occurrence and nothing to be alarmed about.

[Jay Aitchsee]

Don't forget that some centrals are simply normal to experience anyway and don't mean something bad is happening...

Right, that's kind of what I was trying to say when I got carried away with the "real" part

[packitin]

I was just curious, since the topic here is centrals, how many of you, if any, have been the victim of viral encephalitis, like I have.
I've found very little data or topics on it. There seems to be some "hints" that this is the case, but no hard data. For example, here is a statement of a little more than a year ago from a reliable source:

http://www.webmd.com/sleep-disorders/gu ... ep-apnea#1
Conditions that may be associated with central sleep apnea include the following:
• Congestive heart failure
• Hypothyroid Disease
• Kidney failure
• Neurological diseases, such as Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease)
• Damage to the brainstem caused by encephalitis, stroke, injury, or other factors

that seems to imply that there is a connection, but does not give any indication of what it is.

So, my question is, what is your opinion and what other activities, or should I say, accidents, such as a frontal lobe injury, such as I've had from a bike wreck, could be conjectured as relating to the possible increase of centrals.