Apnea Duration

OK so I'm into week 4 of my therapy now.

What is good is that my AHI is now routinely between 1 and 5. The sleep study showed it was 22 (55 when in supine position!)

Less comforting is actually seeing the data verify what my wife alwas said, but I assumed she was exaggerating.

Most of my apneas are quite long, like 30 seconds. Some of them are very long, like 70 seconds!

Has much research been done on apnea duration? is it an important metric?

Any way to lower it?

Pressure is 14. These appear to happen late in the night after 5 hours of uninterrupted sleep. When i was on APAP for 2 week trial I had the same thing even on pressure 20. I'm not sure if pressure can stop this?

Very worried. Any advice?

sgu00dir wrote:Has much research been done on apnea duration? is it an important metric?

Don't know about any such research and yes...duration is kinda important...longer is obviously more stressful on the body.

sgu00dir wrote:Any way to lower it?

Yeah...as long as the apnea events are obstructive in nature (OAs and hyponeas) usually more pressure is needed to better prevent them from ever happening in the first place and/or won't last so long.

Exception being if the events are central in nature (ClearAirway events when using SleepyHead or Centrals when using ResScan).
Centrals we can't fix or prevent using your type of machine and unless you are having a truckload of them there is no need to fix or prevent them.

What machine did you end up getting after the 2 week loaner APAP???
When you have time please add your equipment to your profile so we can see at a glance the equipment you are using.
wiki/index.php/Registering_Equipment_in_User_Profile
Please use the text option...the icony is tiny and we can't tell model name as easy as with text.

sgu00dir wrote: These appear to happen late in the night after 5 hours of uninterrupted sleep. When i was on APAP for 2 week trial I had the same thing even on pressure 20. I'm not sure if pressure can stop this?

If obstructive in nature...most likely either REM stage sleep (late in the night is when we typically have more REM and need more pressure...or maybe you are on your back....or maybe a combination of REM and supine sleeping.
You need more pressure sometimes but not other times....did they give you a fixed pressure machine or an auto adjusting machine.

Can you post a detailed report image????

Thanks for your reply.

Yes its just a fixed pressure CPAP machine with comfort Ramp. It is Resmed Air Sense 10 I think.

I had the APAP for 2 weeks as the overnight study was inconclusive and based on 2 weeks of data they recommended 14 pressure. But I know that I was having very very few but very long apneas even at pressure 20. (sleepyhead confirmed)

Is there anything to do about it?

I think my tongue blocks my airway and no pressure in the world could move a tongue!

sgu00dir wrote:its just a fixed pressure CPAP machine with comfort Ramp. It is Resmed Air Sense 10 I think.

Does it say "CPAP" on the front of the machine or "Elite"?

sgu00dir wrote:Is there anything to do about it?

Well....more pressure if those are obstructive in nature.
When using a fixed pressure machine that means more pressure than 14 all night long instead of some of the time.

If your machine says "CPAP" then that model doesn't distinguish between centrals and obstructives so you don't get detailed reports...all you get is summary numbers which won't help.
Hope it says "Elite" so we can get some detailed reports.

Personally if it were me...I would be wanting the auto adjusting model...where do you live and what insurance (if any) do you have?
I have REM worse OSA and I would need sometimes 6 to 8 cm more in REM sleep than in non REM and I can tell you that it is much nicer to use 10 cm for the 80% of the night I am not in REM and let the machine go to 16 or 18 just for REM time....than it is to use 16 or 18 all night long.

Oh...if 20 cm still let too many apnea events happen you might do better with a bilevel pressure machine.
It will go to 25 if needed and at pressures in those high teens it's just so much more comfortable anyway with the bilevel settings.

Pugsey, thanks. Im in UK so it is NHS. I was a bit sad when they replaced the trial APAP with the CPAP, but thats all they will give me. Im pretty sure it is elite as I have exported to sleepyhead and seen all the data.

So if im right in this, other than increasing pressure, (preventing the apnea), there is no way to lessen the length of apnea?

Im now only having a few a night thanks to cpap, but they are scarily long!! Cant believe I dont breathe for over a minute!

xxyzx, thanks I has thought about getting an oximeter. Any good ones to look for?

I agree, AHI is probably a little bit crude. But Im in UK with NHS so dont think its just to do with insurance. I think that cpap can fix AHI but not event duration hence the focus on it. 5 1 minute apneas is still better than 50 1 minute apneas!

Also, regarding the o2 levels. Surely it isnt possible to maintain o2 levels while not breathing?!

sgu00dir wrote:So if im right in this, other than increasing pressure, (preventing the apnea), there is no way to lessen the length of apnea?

Not that I am aware of...but by using a more optimal pressure in an effort to prevent the airway collapse then when it does collapse the duration should be reduced.
These machines don't do a think while the airway is actually doing the collapse...none of the cpaps or apaps will do anything but sit and twiddle their little thumbs while the airway is actually collapsing. It's only after things have returned to normal that the machines will consider doing anything different and that's only if they can (apaps) because cpaps can't change anything on their own.

sgu00dir wrote:Also, regarding the o2 levels. Surely it isnt possible to maintain o2 levels while not breathing?!

It depends on 2 things...duration and how close together it might happen.
You can hold your breath for 30 seconds once in an hour and I doubt the oxygen levels will drop much if any.
But do 1 apnea event per minute of 10 seconds for 1 hour...yeah...likely O2 levels will change. There's a cumulative effect possible depending on how close together any apnea event is with others...and then of course longer duration really amplifies things.

3 apnea events of 60 second duration within 10 minutes....not sure but that might impact the O2 levels.

Also other lung issues could come into play in terms of O2 levels.

For an overnight recording pulse ox...and it works with Sleepyhead...might look at the CMS 50 D Plus (the Plus is important) or the slightly more expensive 50 E or 50 F
http://www.pulseoxstore.com/overnight-pulse-ox
Using the link just to show you what is available. You can find them at other sources online...EBay is a good one if you want cheaper and are willing to wait on it to come from China.

Are those 70 second events central or obstructive? That's real important to know.

Cool thanks! Really helpful info.

Im going to get an oximeter and conduct my own study into it. I'm certain having apneas over 1 minute are more damaging than 10 second ones but there isnt much research. Ive done a quick search of the literature (im a medical librarian!) and there is not much out there about duration.

This is one interesting study:

https://www.ncbi.nlm.nih.gov/pubmed/28584939

I have found that when I have events that last 30+ seconds ,they are hypopnias (partial blockage). When I have apnia events they are normally 10-20 seconds. Most of my events are H or CA.

xxyzx wrote:

LSAT wrote:I have found that when I have events that last 30+ seconds ,they are hypopnias (partial blockage). When I have apnia events they are normally 10-20 seconds. Most of my events are H or CA.

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hope the experts will have factual data on this
but i would hope the body regulates the O2 it needs and if you did not have hypopnea then it would be hyperventilating due to faster deeper breaths
so that hypopnea per se is not as serious as apnea that stops the O2 completely
although hypopnea could be due to old age or other cause and actually is too low to be safe

in the end the only way to know if it is a problem is to have an oximeter and measure how low and how long the O2 level actually is

Troll...Please do not respond to my posts. I was stating a fact..not asking for comments.

The only thing that's pretty certain is that you're dong better on the machine than you were before.

Speak to the doctor who put you on the machine about the duration of these episodes.