"Centrals" vs. Clear Airway events

[dataq1]

A person (over on that other board) insisted that OSCAR plans to "fix" the terminology clear airway events and index and replace it with central events and index.

There was much discussion about the difference between clear airway and central, with a least some (myself) persisting that actual central events is a subset of the more global clear airway terminology.  

So, my question is: Does OSCAR intend to "fix" the report so it says "Central Apnea Events" ?

[Gideon]

OSCAR reports it in the verbage of the manufacturer.
No one can completely correctly determine a central apnea has taken place without seeing the absence of a neurological signal to breathe. No CPAPs measure brain activity. Therefore no CPAPs can 100% determine that a central apnea takes place. What you can see, via various probing techniques is if the airway is restricted or not. A non-resricted event is classified either as a Central Apnea or a Clear Airway event depending on manufacturer. Typically they are considered the same or equivalent.

This is a function of OSCAR being a reporter of the data, not the manufacturer of it. And yes it is confusing.

Same goes for CSR vs Periodic Breathing. That is IMHO worse because very few people actually have CSR and most at least somewhat panic at seeing the CSR flag on their report.

[pholynyk]

It's hard to say just what a 'fix' would be. None of our machines can detect a 'central' because we have no neurological sensors. A 'clear airway' on the other hand can be detected by means of air pressure pulses.
So we should call them all 'clear airway' events, right? Well, not all the manufacturers do, so users get confused. In theory, we could change OSCAR to use the manufacturer's terminology. That's a fair bit of work, and I doubt that the OSCAR team will get to it any time soon. And, of course, there will be people who still aren't satisfied.

[dataq1]

Thanks Gideon,
I take that it will remain "Clear Airway" (at least for Resmed and Phillips home machines) until they start to call it something else.

My sole point (in the other board) was that users who have a significant (say, > 70%) fraction of their AHI assigned to Clear Airway events ought to try to clarify if those events are just SWJ as contrasted with  pathologically inspired, or drug inspired, or altitude inspired, treatment-emergent inspired etc.  Obtaining that clarity may require professional medical assistance. 

BTW, I agree about the Cheyne-Stokes, a diagnosis of that is best left to professionals.

[dataq1]

So we should call them all 'clear airway' events, right? Well, not all the manufacturers do....

Just out of curiosity, what manufacturers do not use the term "clear or open" airway to describe an clear or open airway apnea?  I am only acquainted with Resmed and Phillips home machines and both describe a 10 second apnea with no obstruction as a "clear airway apnea"

So there are others that don't use that terminology to describe the 10 second apnea with no obstruction?

[DaveInDenver]

fwiw, the ResMed AirSense 11 Clinical Guide uses the terms 'Central Apnea' and 'Central Sleep Apnea' 11 times, and does not use the term 'clear' wrt apneas or airway any times.

[TecFive]

fwiw, the ResMed AirSense 11 Clinical Guide uses the terms 'Central Apnea' and 'Central Sleep Apnea' 11 times, and does not use the term 'clear' wrt apneas or airway any times.

True enough, however they do refer to "central" as an open airway condition:
 
"During a central apnea, the airway will remain open, but there is no flow."

The issue of central apnea  becomes more critical (and frightening) when Resmed (in their public facing blog) [see below*]  discusses central apnea "Five major types of central sleep apnea causes" each of which would/should cause a patient to run to  their doctor asap.

There is no mention of "central" apneas being caused by sleep-wake "junk" or sleep-stage transition etc. 

Ultimately, can a person be diagnosed with "Central Apnea", via a home XPaP ?  I'm suggesting no, that diagnosis is best left to medical professionals. 

Unfortunately, a great many patients see their OSCAR report as a diagnosis rather than a clinical observation.

OSCAR's reporting of "Clear Airway Event" makes a lot of good sense, and is just a clinical observation. 


* not permitted to add link - need to have posted 4 times or more
however, if you will type into google:
"resmed.com/en-us/sleep-apnea/sleep-blog/central-sleep-apnea-causes"

hopefully it will take you to resmed's blog

[tdoty821]

My personal experience...I've had a significant amounts of "Clear Airway" events tagged by my ResMed 10, with nearly 0 "Obstructive" events for years. I'm religious with my download of data into Oscar. It provides us a detailed view (breath-by-breath) of the recorded data on our machines. My advise to anyone seeing growing or large numbers of tagged Clear Airway events:

1) Drill down to each event and look at how long the event lasted. Make notes and see if the data is trending in one direction or another.

2) If your individual events are longer then 15-20 seconds consistently, AND your having 20,30,40 or more...it's time to take your notes AND Oscar data to your doctor.

3) Don't let you doctor brush these events off without a sleep study.

4) Home based sleep study equipment which doesn't include some EEG monitor to gather brain activity WON'T clinically diagnose "Central Apnea" events.

Bottom line --- Oscar is not a doctor, it's an AMAZING tool we should all use. But we need to be STRONG advocates for our needs.

[DaveInDenver]

I just finished up drilling down on my CAs.  Most of mine seem to be 10 to 15 seconds, and usually less than 5 per night.

Noob question: Would it be recorded as a CA when I stop breathing to swallow in the middle of the night?  I don't know the exact mechanics of swallowing with the nasal cushion mask on, but it does take some fancy internal contortions to swallow.

[Crimson Nape]

If your swallow impedes your breathing for 10 seconds or longer.

- Red