The 4th hour

[caffeinatedcfo]

Therapy is going well overall, but I am still trying to understand sleep cycles better. I usually hit the sack at 10pm every night, with occasional adjustments. However, one thing remains the same ... I always wake in the 4-4.5 hour mark from a 'normal' dream. I usually do not have any difficulty falling back to sleep, but I notice on my S9 data that there is almost always an OA flag at these times. This also tends to mark the first upward change in pressure from my min 10cm. There is usually a minor, brief spike in the leak line too indicating I opened my mouth. No question in as to the fact the OA woke me. I'm wondering what sleep cycle that would be?

[RandyJ]

By 4.5 hrs into sleep you could be entering the third (and usually longest) REM cycle of the night. Maybe for some reason you are getting an event then that you are not getting in the first 2 cycles due to deeper sleep... a pressure increase would explain the mouth opening, especially if you're on your back.

Some people (Pugsy included) talking about having the majority of events in REM phase sleep. If you are on your back it's likely to be worse.

[Pugsy]

Here's a normal hypnogram below. You are probably waking during REM sleep for some reason. Maybe that little pressure increase or maybe that little leak.

My "witching" hour is almost always the first REM stage sleep.. I almost always have increase in pressure and a little bit of leak around 90 minutes into sleep but it doesn't wake me up that I remember. A good 3/4 of my reports have some sort of activity right around the 90 to 120 minute mark every night. Sometimes also in the wee hours of the morning where we have more REM sleep and it lasts longer.

This may just be a pattern that you will always see. Your "normal".

[caffeinatedcfo]

Thanks! I am still in "kid with a new toy" mode with my machine and treatment. I am disappointed in the 2nd sleep study because it was NOT a normal sleep pattern night for me for obvious reasons. So nothing other than the OSA/CPAP data is useful.

[DynoDad]

Interesting. I've been using CPAP for about 18 months now, and every night without fail I wake at 4 hours +/- 15 mins. Usually I can't get back to sleep so I lie awake for ages, go to the loo, have a drink etc and eventually take the mask off and I'm out like a light. Sometimes I'm not aware of waking, but I switch the machine off and remove my mask without being aware. I then wake up in the morning initially pleased that Ive slept all night only to wonder why the mask is lying on the floor and the machine is off. Without the machine I sleep 8 hours solid, but not using the CPAP is definitely not an option.

According to this article http://www.bbc.co.uk/news/magazine-16964783 on the BBC it's quite common and the answer might be to get up for a couple of hours and then go back for a second 4 hour sleep. Would love to find a cure for this.

[caffeinatedcfo]

I think my problem is that I am getting into longer periods of deep sleep around then and my pressure needs change, but lately an OA occurs during a REM cycle (I wake from a dream).

I'm contemplating increasing min pressure beyond the prescribed 10cm.

[Sir NoddinOff]

I think my problem is that I am getting into longer periods of deep sleep around then and my pressure needs change, but lately an OA occurs during a REM cycle (I wake from a dream).

I'm contemplating increasing min pressure beyond the prescribed 10cm.

I don't have an opinion about pressure increases, but throwing some stuff at the wall... Do you have to pee when you get up, even if your bladder isn't full? Caffeine and stress are often issues, or so I hear. If so, check this forum search engine for 'nocturia' or...

http://medical-dictionary.thefreedictio ... m/nocturia

[caffeinatedcfo]

No I did not have to use the bathroom. My nocturia decreased when I started CPAP and ended when I switched to the Swift FX Nasal Pillows and started sleeping longer. I simply wake - not jump out of bed awake, but my eyes open, I note the time for comparison with my data later, then generally go right back to sleep within a few minutes. Maybe the aliens are still pulling at me but just more gently.

[RandyJ]

It's probably hard to determine what is making you wake up at roughly the same time in your sleep cycle every night. For now, you may want to simply record it for a few weeks and continue to correlate with your pressure and events graphs to look for clues. You really need a few weeks' data at least before you can say that it's definitely an OA, or a pressure increase, that is waking you.

I know you are using APAP, but eventually if you suspect that pressure increases are waking you and not something else, you might want to try cpap and see if you still wake up. Many people prefer a constant pressure because they are sensitive to pressure changes.

I am not recommending you do so at this time, but just know it is an option down the road.

[eeckel]

http://en.wikipedia.org/wiki/Segmented_sleep

Have you considered a segmented sleep explanation that sirniddinoff suggested? I was fascinated when I read Roger Ekirch's At Day's Close: Night In Times Past.

[caffeinatedcfo]

I know you are using APAP, but eventually if you suspect that pressure increases are waking you and not something else, you might want to try cpap and see if you still wake up. Many people prefer a constant pressure because they are sensitive to pressure changes.

Great point, Randy. By leaving it in APAP mode I may be inadvertently chasing the 0.0 AHI and 10cm may prevent a suffient number of OAs. I'll continue monitoring for a little longer.

http://en.wikipedia.org/wiki/Segmented_sleep

Have you considered a segmented sleep explanation? I was fascinated when I read Roger Ekirch's At Day's Close: Night In Times Past.

I like where this is headed and will discuss with the wifey - in the interest of science, of course.

[RandyJ]

Great point, Randy. By leaving it in APAP mode I may be inadvertently chasing the 0.0 AHI and 10cm may prevent a suffient number of OAs. I'll continue monitoring for a little longer.

If you do decide eventually to try cpap there is a way to decide what pressure to use based on what your 90% pressure average was on apap. But I stress that it's too early for that.

You may even eventually determine that your waking is unrelated to pressure changes.