when do you get concerned about CAs?

Using SleepyHead, I find that on most of the 12 nights I've used CPAP so far my clear airway events are at 0 or very close. On two occasions, the first night I used it and then last night, I got above .80. Is that acceptable? I had a cluster of events (5 of them) within about a 6 minute window in the middle of the night. Would you consider that nothing to worry about, something to keep an eye on, ?

What is your threshold for becoming an issue worth discussing with a doctor? My assumption is that this is not even worth giving a second thought, that having it < 1 makes it trivial. But I thought I'd better check with those who have much more experience.

Iowamv wrote: On two occasions, the first night I used it and then last night, I got above .80. Is that acceptable?

Quite acceptable.

Iowamv wrote:I had a cluster of events (5 of them) within about a 6 minute window in the middle of the night. Would you consider that nothing to worry about, something to keep an eye on, ?

I wouldn't worry about them unless I saw it happening frequently during the night and for multiple nights.
I once had 17 centrals in 17 minutes. One per minute. Looked pretty impressive but that was the only time it got that exciting.

Personally, I don't worry about random clusters of anything. It's when I see clusters of whatever happening consistently night after night that I start looking for answers.

Sometimes I have seen clusters of centrals when I know for sure I was awake....like the time I woke up for about an hour battling extreme nausea and trying to decide if I needed to make a run to the bathroom to throw up but didn't.
So I know that the machine can and will flag awake breathing by mistake...plus we all have centrals from time to time. It's normal and even people without OSA diagnosis will have them.

If they really concern you though....talk to your doctor about them but unless my AHI is consistently over 5 with predominance of centrals I don't worry about them. You will find that there will be nights where you don't have any and then the next night you might have 20 or 30 total all night of them and then the next night none again.

+1 to everything pugsy has said.

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Prevalence of Central and Complex Sleep Apnea syndromes


Predominant central apnea is uncommon and is seen in less than 10% of patients presenting for PSG.
In the general population, the prevalence of central sleep apnea is less than 1%.

Complex Sleep apnea is detected in up to 18 percent of patients who undergo positive airway pressure titration for OSA .

(The only way to verify if you’re one of these folks is by a Sleep Study in a Sleep Clinic.
Unless you’re amongst them you don’t need to worry much about seeing Central Apnea events in your treatment data.)

Check this:

http://emedicine.medscape.com/article/304967-overview

The term central sleep apnea encompasses a heterogeneous group of sleep-related breathing disorders in which respiratory effort is diminished or absent in an intermittent or cyclical fashion. In most cases, central sleep apnea is associated with obstructive sleep apnea syndromes or is caused by an underlying medical condition, recent ascent to high altitude, or narcotic use. Primary central sleep apnea is a rare condition, the etiology of which is not entirely understood.

There are several different entities grouped under central sleep apnea with varying signs, symptoms, and clinical and polysomnographic features. Those that affect adults include primary central sleep apnea, Cheyne-Stokes breathing-central sleep apnea (CSB-CSA) pattern, high-altitude periodic breathing, central sleep apnea due to medical conditions not Cheyne-Stokes, and central sleep apnea due to drug or substance.
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Some people have found that excess alcohol consumption will cause centrals.
Be aware before you party too hearty.

I want to second the thanks to the original poster and peeps who answered. I'm still getting some CA's myself and was wondering what the threshold was.

Tanks mon!
TheWino

Thanks for the info everyone!

Look at the airflow waveform of CAs, too.

If they're 11 seconds long or not complete cessation of breathing, it's not that worrying if you don't have too many.

If they're 120 seconds long of complete non-breathing, it's a bigger problem.

Since I didn't see this pointed out...

The machine's ability to detect Central Apnea is quite limited. In fact, a 'CA' is *NOT* a central apnea ... it is a "Clear Airway" apnea. The distinction, minor though it may seem, is simply that the machine is missing key pieces of information: whether you are truly asleep and whether your lungs are moving. All that it knows is that at the machine end of the hose there doesn't seem to be a variance in air flow, and that it can "shoot pulses" of air that don't encounter resistance (if they did, it would be scored as obstructive).

If you see large amounts of leakage at the same time, then the CAs are meaningless ... the pulses that MIGHT have scored as obstructive are hidden by the leaks. Further, you might be breathing fine but the leak could be misleading the machine in to thinking you are not.

Lacking EEG information, the machine can't tell what state of sleep or arousal you might be in. You might be in that in-between state where a lot of misleading information happens (often referred to as Sleep-Wake Junk and other similar names).

If anyone is worried about CAs, the best thing you can do (short of talking to your doctor) would be to post some data so we can see what contributory factors might be present. In a very large percentage of times I've seen that done there was collective belief that not much was really happening. Of course, there's the occasional "Hmmm ... better get that checked out", or a suggestion to try a lower pressure, etc..