Clear airway events

[salton]

I had my sleep study a couple months ago. No Centrals were observed. Now I am showing quite a few CA's on my reports.
Am I safe to presume that these are not centrals? The equipment used in the study is more accurate, no? I doubt that I am having centrals if none were observed during the study. Should I disregard them entirely?

[Drowsy Dancer]

I had my sleep study a couple months ago. No Centrals were observed. Now I am showing quite a few CA's on my reports.
Am I safe to presume that these are not centrals? The equipment used in the study is more accurate, no? I doubt that I am having centrals if none were observed during the study. Should I disregard them entirely?

(1) You can't assume that they are not centrals, but you also can't assume that they are. You could be awake, and hence breathing less regularly, when the machine is noting clear airway events.

(2) Yes, the equipment used in the study is more accurate, but...

(3) You could be having centrals now, even if none were observed in your study.

Some people, when they begin using CPAP, will have a lot of centrals for a while as they get used to the machine, and then the centrals go away.

Some other people, if their prescribed pressure is too high for them, will start having centrals that will go away when their pressure is adjusted downward.

I have no idea whether you fall into either of these categories.

So although there's no reason for immediate alarm, I don't have enough information to blithely advise you to disregard them entirely.

[squid13]

If you hold your breath while you roll over or what ever your doing for longer than 10 seconds it scores as a clear airway event.

[Pugsy]

How many centrals are we seeing in the reports now? Per hour?
Are they showing up right around going to bed time or wake up time?
Or are they scattered about randomly? Or big clusters.
Do you spend much time on the machine with mask on laying awake for periods of time?

They are probably centrals in the sense of the definition of a cessation of breathing with the airway being open but not all centrals means something alarming is going on. We all have centrals from time to time. Some are "real" in the sense they would likely have been flagged during a sleep study but we also have centrals (by the definition) that wouldn't have been flagged during a sleep study.
Hold your breath for 15 seconds...that is what happens when a 15 second central gets flagged.. No air movement but airway is open. Not a big deal if you do it once per hour...might be a problem if you did it once per minute for 15 to 30 minutes.

So before we start trying to figure out if what centrals you are seeing are "real" or not...let's see if the number of them is even worth more detective work.
If you are seeing 1 or 2 per hour scattered randomly through the night the doctors are unlikely going to be concerned.
Now if you are seeing 5 to 10 to 20 per hour...every night, every hour...we probably should be doing some detective work.

[salton]

Last night is my best night so far. AHI 4.92 Obstructive 1.78 and CA 2.46. I also feel absolutely fabulous today.
I have been playing with pressure a bit and exhale relief and went back to the medium pillows. My AHI for last week was just under 8.
My CA's are pretty spread out, but seem to increase in the couple hours before getting up.

[Pugsy]

CA's are pretty spread out, but seem to increase in the couple hours before getting up.

I see that sometimes myself. I think I start waking up..maybe wake up and don't remember it and then go back to sleep.
It is normal to have centrals (real centrals) during sleep onset and sleep stage transition. They are turn over in bed hold your breath centrals but unless you are having a truckload of sleep onset centrals we don't get all excited.

I know that the nights that I remember waking often for some reason or have a restless night (usually because of pain) that I am likely to see more centrals. The nights with minimal wake ups that I remember...very few centrals.
So I assume that most likely my "centrals" are a combination of turn over in bed hold your breath centrals and a few sleep onset centrals because when I have a bad night with several awakenings due to pain...I know I also do a lot of tossing and turning so the chances of having both kinds of "centrals" are pretty high...I move around a lot and if I remember a lot of awakenings that also means I had a lot of sleep onset stages where centrals can occur.

[Todzo]

I had my sleep study a couple months ago. No Centrals were observed. Now I am showing quite a few CA's on my reports.
Am I safe to presume that these are not centrals? The equipment used in the study is more accurate, no? I doubt that I am having centrals if none were observed during the study. Should I disregard them entirely?

Hi salton!

Keep in mind that you do not sleep the same any two nights, weeks, months, seasons, or years. Your body is constantly changing.

Also keep in mind that your sleep study is accurate only for that time and in that situation. They do not measure how you sleep at home.

Work with those here who love to teach how to read and use your data and do so a couple of times a week. What you know now is that you occasionally stop breathing with a clear airway. If you see greater air use preceeding it may be a hypocapnic central apnea. If you see greater air use proceeding it probably was a breathing disordered event. Think about how you are breathing as you look at the actual flow waveform close up.

Have a great week!

Todzo

[archangle]

From what I understand of the science and technology involved, I believe:

1) If it says "central" or "clear airway," it probably IS a central.
2) It may mistake a real central apnea as an obstructive.
3) It will show some kind of apnea.
4) Even if it is a central, it's not necessarily any more harmful, just harder to eliminate. The harm comes from how long you don't breathe and how often, not whether your airway is open or not.
5) Check the duration. Long duration apneas are much more important than short ones.