I wrote earlier about the question "When does a difference in degree become a difference in kind?"
I think this question applies to Sleep Apnea.
There is something called the AHI or "Apena/Hypopnea Index". It is simply the average number of apnea events per hour added to the average number of hypopnea events per hour.
(Apena events - you stop breathing; Hypopnea events - you breath very shallowly.)
Everyone stops breathing at night (amazingly) and an AHI under five is considered "sub-clinical" or "not interesting."
Some doctors think an AHI over twenty is "very serious" and some think an AHI over thirty is "very serious." My AHI when sleeping on my back without a CPAP machine was over NINETY.
There are stories about people who stop breathing for a minute or two or three at night. In extreme cases these people turn blue from lack of oygen! It puts tremendous stress on the heart and lungs and brain and pretty much the entire system.
But think about it ... if you stop breathing for a minute or two at a time, then the highest your AHI index can be is 60 (you stop breathing for a minute every minute) or 30 (you stop breathing for 120 seconds every two minutes). And that's not really possible because you have to take some time to breath and catch up.
I suspect that if someone stops breathing for two minutes at a time then their AHI index is thirty or lower. The biggest problem for people with a lower AHI is that they suffocate for a couple of minutes repeatedly during the night.
Well, at an AHI of 90, assuming you take time to breathe, you are having an apena event every 40 seconds. Since they last at least 10 seconds you are alternating between breathing and not breathing at a rapid rate, probably every 20 seconds.
Since the way your brain wakes you up is a little shot of adrenaline, that means you have a little shot of adrenaline every 40 seconds all night long.
In fact, my body won't let me fall asleep on my back - I can't go to sleep - I stay awake because my body starts with the adrenline right away! This is true even with the CPAP machine on. Later, after I've been asleep a few hours I can turn onto my back. But not at the start!
On my side the AHI index is 65 and on my tummy the number is unknown. After more research I doubt it is zero. It could be or it could easily be 40. That's still a lot of adrenaline and very little time suffocating.
Which is the long way around of saying that an AHI over 50 or 60 is pretty much a different disease than one where the index is 20-40.
I haven't found any research on this on the Internet. I'm meeting my sleep doctor on Tuesday and I plan to drill him about this. My opinion now is that 'regular' sleep apnea - cases where the AHI is below 30 or maybe 40 - should have one name and cases where the AHI is above 40 should have another name, like Sleep Apnea/Adrenaline Syndrome.
[Note 4/12/2006: my new sleep doctor says that regardless of AHI some portion (20% I think he said) of people with Sleep Apnea simply do not have any symptoms other than snoring and 'snarking' as people call it when you wake up slightly and go back to sleep. He's a good guy - he admits they don't know everything about it.]
© 2005 Stephen Clarke-Willson - All Rights Reserved.