AHI skyrockets at the end of the night

[Jiipee]

Hi,
I've been using CPAP machine for a few months now so I guess my body is still getting used to it. After I started using it my nightly heart rate went from over 70 to 50-65 average so it decreased dramatically.

Even though I use the CPAP machine I still do not sleep well. I guess it's a combination of lots of problems but there is one particular thing I'm a worried about. If I have a really long sleep at the end of the sleep my AHI skyrockets and I start to get these CA (Clear airway) events one after another. When I get up from bed my blood pressure is higher than normal and I feel like I'm climbing out of quicksand aka I feel super powerless. After waking up it takes some time to get back to feeling normal. The blood pressure also returns to normal levels (slightly elevated) in some minutes.

This "rising from the grave" feeling is also present if I take a nap during the day. I wonder what could this be? Is my heart having trouble keeping my CO_2 and O_2 levels normal or something like that. This could be something that cannot be dealt with CPAP machine but if anyone has similar experiences or any knowledge about this I would appreciate it. Screenshot from Oscar attached.

   

[ArcherNeedsSleep]

It looks like your leak rate kicks up at the same time the CAs are showing up.  Do you toss and turn as you wake up?  Or do you tend to have active dreams in your last REM cycle?  I wonder if those CAs aren't real events, but more representative of you moving and triggering leaks that tend to confuse the machine.

[PeaceLoveAndPizza]

Archer is on the right path.

Are those typical for you or a one-off? If a one-off then they are likely sleep-wake junk. Basically you are awake but trying to sleep, so you are getting normal awake breathing flagged as a CA. CPAP machines only deal with sleep breathing, so awake breathing confuses them. If it occurs nightly then we may have a different problem to handle. 

You can try adding a bit more pressure to see how things feel. A min IPAP pressure of 6 is too low for many, so that may be part of the problem. Even with a good AHI, the low pressure causes deeper breaths (more arousal breathing), hence the spikes in your flow rate.

Try the following:

Mode APAP
Min pressure 8
Max pressure 12
EPR 2 full-time
No ramp

That should help with the pressure swings and hopefully be more restful.

[Jiipee]

Thank you for the replies ArcherNeedsSleep and PeaceLoveAndPizza. I think you might have solved this "mystery" for me. I just couldn't realize it myself. It's probably just me moving in the bed while having a restless sleep. There are some facts that support this:

1. My Withings sleep analyzer registers high sleep apnea activity during those events. Since it can only register movement and listen to noise I make it probably cannot differentiate movement in bed with actual sleep apnea events for 100%. 

2. Most of the time when these CA events happen I have some leaks before, during or after the events. I guess leaks are more prone to happen during movement/changing position in the bed.

3. I got a medication for restless legs syndrome. It should make me move less in the bed. When I started to use it those AC clusters have not been there during the first 6-8 hours of sleep. Before that they could happen during the night also. Not just during the end of the night. Also Withings sleep analyzer says my Sleep apnea index is way lower after using the meds so I guess it registers less movement. The index gets higher during those CA clusters so it could mean its registering movement in bed.

So what I would conclude is that the CA events happen because I move in the bed. Since I've had the meds that calm me down a bit my movement has decreased dramatically. This means having more deep sleep and less Sleep apnea events registered by Withings sleep analyzer. The CA events that happen at the end of the night are me moving in the bed and sleeping restlessly. I guess I've already had enough sleep at that time and my body is ready to wake up or I just start to feel uncomfortable at the bed because I have some back problems. 

Regarding the "rising from the grave" feeling when waking up from long sleep or nap I think it is called sleep inertia. Maybe I am a bit sleep deprived so that could explain the heavy sleep inertia I have. I sure hope it goes away someday... Last year I had it during the spring and beginning of summer but it went away on august so I guess there is hope left. The strong sleep inertia feels really bad so I wouldn't mind if it got alleviated a bit...

I will try the minimum pressure 8 and max pressure 12 settings and see if it helps. I might also tighten my mask a bit more since I wear it quite loose.

[HalfAsleep]

@jiipee your reasoning looks very sound. Yep, follow P&L’s settings instrux, post some new Oscars, and go from there.