higher AHI as night progresses?

[winknblinknnod]

Hi, I've been tracking my stats as my machine offers this feature. AHI is ranging between 1.8 and 5. I am assuming the daily stats are an average for the hours slept that night.

Some nights I still end up with the mask off and don't rouse myself to re-apply it to my face. Here's my question: The less hours I sleep, the lower my AI HI and AHI. For example, last night I only managed 2.5 hrs with the mask, and during that time, there were no leaks, no AI and very very low HI. Last week, I had a night with 4 hrs on the mask and the no's were about mid range.

Ususally, I'm getting @ 7 hrs. and fighting to keep the stats below 4 - 5.

Does this imply that the deeper I get into sleep, the more occurences of apnea I have? Or is this some glitch of the software? My numbers were way high until I put the ramp function back on, then they were much better, which I took to mean the machine was waiting 'til after the ramp time to start tracking events.

Thanks!

[inacpapfog]

I think that's pretty normal. Like you refer to, the very relaxed stages of sleep seem to allow for more AHIs.
Most of my events happen later into the night (after 3-4 hours.)

[Dale92]

That is also my experience! I get to sleep and about 2 to 3 hours into my sleep is where I typically have most of my apneas though some days if I am extremely tired they start immediately. I guess it depends how fast you get to a deeper sleep.

Dale

[Sleepless in St. Louis]

I have observered the same thing. It seems that at about 2 hours into sleep is when SDB events begin to occur for me. My trusty auto is on duty though (all of three nights with the auto so far) to zap the obstruction into submission. It seems to do its best work while I sleep on the job.

[Knightfall]

Here's my question: The less hours I sleep, the lower my AI HI and AHI.
Thanks!

I have been experiencing this also. I have been retrieving the data via the LCD and trending it in Excel, and I plotted hours used vs AHI for fun, and it's weird how the two almost identically follow each other in my case. And I would agree that less hours of sleep = lesser depth of sleep = lesser chance of breathing obstruction. My sleep doc just bumped my pressure up from 9 to 11 cm/H2O (straight CPAP); I'll be interested in seeing if that trend remains, or if it remains the same.

Off the topic, I see you list the reader in the "software catergory. Are you using the Resmed Autoscan software, and if so , do you like it?

Thanks, Ken

[tooly125]

My doctor told me that during the REM stage of sleep is where I have my worst apneas also when I sleep on my back.

Maybe the longer you sleep the more chance of both these situations occurring?

[winknblinknnod]

I started with the Resmed Escape, but didn't like it, and got the Elite for the EPR feature.

I didn't get the software, I just check the efficacy data on the clinical menu every day. Dr. authorized access to the clinical menu so I could adjust my CPAP pressure myself. He wouldn't prescribe an auto though, go figure.

[rested gal]

I think Tooly nailed it. REM periods normally get longer as the night progresses. The longest REM occurs near morning. Apneas and hypopneas are most apt to happen during REM.

[Snoredog]

Here's a pretty good illustration of how your sleep progresses throughout the night, everyone is a bit different but you can get an idea why you spend more time in REM. If your looking at sleep architecture from your PSG, you can see why Stage2 is always so high: