Worried about few, but long centrals

[alexander]

My AHI is normally around 0.5–2.5. My CAI is around 0.75. When I look at a typical week of data I’ve got 3–4 days with at least one central over 20 seconds. Some of my centrals are as long as 27 seconds. Most over 20 are less than 25 seconds.

When I visited my sleep doctor she wasn’t worried, and said that I probably took a long in-breath before breathing out. I decided to look at the events, and in general I did’t see in-breaths right before the events. I don’t think in general the centrals happen when I’m awake either. I almost cannot not breathe for less than 10 seconds while awake.

My questions are – should I worry about this at all? Is it normal? Would I be better off with an ASV – or is that only for higher CAI (and/or even longer apneas)?

Here are a couple of flow rate screenshots:

25 seconds long CA:



27 seconds long CA:

[Pugsy]

You weren't asleep right before the CA flagging.
They don't count if you aren't asleep.
Most people can easily hold their breath for 30 seconds....no big deal. Listen to your doctor.

If you can't hold your breath for 10 seconds without problems then you need to be seeing a lung doctor.

ASV machines are used when people have a large number of centrals WHEN ASLEEP.
Even a large number of centrals when awake won't cause a need for ASV.

You don't need ASV.

[alexander]

Thanks for the answer, Pugsy!

I don’t want to take this experiment too far, but I was right now, without too much effort, able to hold my breath for 30 seconds when taking an in-breath right before. Without taking an in-breath it started to feel uncomfortable around 15 seconds.

[alexander]

I’m sorry, but I just need to get to the bottom of this.

I haven’t looked at the minute ventilation graph until now. I looked at it the night where I had a 27 seconds long CA. The lowest minute ventilation value was 1.88. When I looked at the minute ventilation waveform across entire night this seems like the lowest value. I have no idea what is a good or bad minute ventilation number, and what duration it can have at low numbers before it is harmful for the body.

Does a dip in minute ventilation might equal a dip in blood oxygen levels? Does it do much harm to the body if there is just one such dip in minute ventilation/blood oxygen levels every third night or so? Does it look good overall when looking at the minute ventilation graph for the whole night?

27 seconds long CA:



27 seconds long CA (whole night):

[palerider]

Thanks for the answer, Pugsy!

I don’t want to take this experiment too far, but I was right now, without too much effort, able to hold my breath for 30 seconds when taking an in-breath right before. Without taking an in-breath it started to feel uncomfortable around 15 seconds.

Centrals are just your body *not needing to breathe*.

That 'uncomfortable feeling' is the buildup of carbon dioxide in your blood, and your body needing to get rid of it.

For whatever reason, (we can speculate, but there's no hard and fast proof), you just didn't need to breathe for a bit, there's no harm in it... if you had an oximeter on your finger, you probably wouldn't have even noticed any drop in oxygen.

Now, if you're having a lot of centrals, even fairly short ones, all clustered together, then your oxygen levels can start to drop, and then it's a concern.

[palerider]

I’m sorry, but I just need to get to the bottom of this.

Set up a camera, time sync'd to the cpap, and see what you're doing.

You're making mountains out of molehills.

[alexander]

Set up a camera, time sync'd to the cpap, and see what you're doing.

I might do so at some point, but right now I’d just like to get your opinion with the data available in OSCAR.

You're making mountains out of molehills.

Not arguing against that.

[alexander]

Centrals are just your body *not needing to breathe*.

That 'uncomfortable feeling' is the buildup of carbon dioxide in your blood, and your body needing to get rid of it.

For whatever reason, (we can speculate, but there's no hard and fast proof), you just didn't need to breathe for a bit, there's no harm in it... if you had an oximeter on your finger, you probably wouldn't have even noticed any drop in oxygen.

Now, if you're having a lot of centrals, even fairly short ones, all clustered together, then your oxygen levels can start to drop, and then it's a concern.

Thanks for the reply. It’s probably harmless then.

[palerider]

Set up a camera, time sync'd to the cpap, and see what you're doing.

I might do so at some point, but right now I’d just like to get your opinion with the data available in OSCAR.

Well, you got that

[djams]

Maybe this'll put your mind at ease. I see the exact same thing. All of my CA's look like this, I've noticed them over 30 seconds. Usually between 10-15. Post arousal/sleep onset, whichever. The arousal isn't anything that I remember. Something disturbed my flow rate. Maybe I moved my leg, maybe I rolled over, maybe I swiped a away from my ear. Don't know, don't really care.

You should just be glad that the CA's aren't real. They wouldn't be counted in a sleep study - just the way you and I go back to sleep once in awhile. No big deal.

Worry about the obstructive stuff. There's nothing we can do about these anyways, except sleep with no arousals, which would be very abnormal. BTW - this has an official acronym here, SWJ (sleep/wake junk)

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