Did my machine malfunction?

[Grandpapa-G]

        I have been using my Resmed A10 Autoset for about two years without any issues - until yesterday.  That night I fiddled slightly with the settings (dropped min pressure from 7.2 to 7.0 and decreased EPR from 3 to 2).  My resulting Oscar pressure graph is strange at the beginning of the second sleep segment. the pressure can be seen to ramp up linearly (ramp is off) to max pressure then begin to decrease linearly until encountering two, probably bogus, OA's.   I know I was awake during this time as my respiration rate had dropped and flow limit had flat lined (this is a usual occurrence for me after every bathroom break).  On the following night I rebooted the apap (pull power plug for 30 sec.) and left everything else the same.  The result was a normal (for me) set of Oscar graphs.  I would like to know if anyone can explain the behaviour of the first day's pressure graph?
As for the large number of central events, I had, shortly after beginning cpap therapy learned to ignore the centrals as they occur during sleep (or sleep / wake junk). My second sleep-lab visit confirmed this. I also suspect the majority of the hyponeae are centrals. I do not feel an ASV is needed as I feel well rested and usually get 8- 9 hours of sleep per night - a great improvement on the pre-therapy days.

[Dormeo]

I don't know why your machine raised the pressure after your break on the first night, but I do have two questions.

One is whether your O2 saturation levels have recently been measure during the periods with repeated CAs. The other is whether you could post a zoomed in view of about 2 3 minutes, capturing several CAs. I think that might help the experts advise you about whether you are right to dismiss the significance of the CAs. Maybe so, but it'd be good to make sure.

[Gideon]

You have a strange 1:15 period after your break. 7 Feb, and except for the "ramp" after the break is very similar to 8 Feb.

1. A much reduced and erratic RR
   
2. No Flow Limitations
   
3. erratic Flow rate
   
4. excessive CA events
   

Otherwise, your pressures are driven by your flow limitations with your pressures limited by your settings.

Looking at 2-3  minute charts should show more on what is going on.

[DeepBreathing]

I know I was awake during this time as my respiration rate had dropped and flow limit had flat lined (this is a usual occurrence for me after every bathroom break).

You really lie awake for an hour after every toilet break? If so, you should probably get some treatment for insomnia. I think it's probably the case that most of us severely over-estimate the time we are awake at night (or underestimate the time asleep). It might seem like hours but I'm sure you probably slept for at least part of that time. Regardless, you say the sleep study confirmed your experience, which makes me wonder if they have any comments or suggestions on how to improve matters. All those centrals (whether awake or asleep) can't be good for you.

Another question - does your machine have auto ramp, which progressively increases pressure when it senses you're asleep? Maybe this (combined with your very erratic breathing) is coming into play?
https://www.youtube.com/watch?v=YcieMbspXYo

[Geer1]

When posting images zoomed in more on those periods include mask pressure as well.

It looks like the machine is behaving like it is in auto ramp mode. Both days at the beginning of night and after being turned back on it held or manipulated pressure and was not recording flow limitations until your breathing evened out. That would kind of might make sense if ramp was on but you say it is off. Maybe try cycling ramp on and then back off to see if that changes anything.

[Grandpapa-G]

I did not intend this to turn into a discussion of my therapy but I should add more background.  Before I reached my teens (50+ years ago) both my identical twin brother and I realized we had a larger lung capacity than most of our friends as we were able to swim longer distances underwater and hold our breaths longer than all others (altho we were poor swimmers). Now we are in our 70's we can still surprise nurses and others while undergoing lung capacity measurements (allergy tests, fitness tests, etc).  When I was a teenager I read an article on how athletes relax before a big meet.  I learned deep breathing techniques and still unconsciously follow the routine today when resting.  When going to sleep after my bathroom breaks I am not wide awake, probably sleep / wake junk is a more apt term. At this time I often have periods of what I believe is lucid dreaming that I quite enjoy. these periods predominately occur during the second half of the night (following the characteristics of first sleep second sleep).
I believe most of my so-called CA's occur simply because the time between breaths exceed the arbitrary 10 second limit.  This was confirmed on my second sleep lab study (on a bipap). It was a bit of a disaster - I became totally aroused every time the Respironics machine changed pressures (it was an abrupt transition, unlike what I was used to with the EPR setting on Resmed).  However the doc was able to see that in CPAP mode there were numerous times the time between breaths exceeded 10 sec, but he said I was not asleep and the pulse Oxygen level did not drop to unacceptable levels. I have attached a screen shot detailing the periods of frequent CA's in my previous post.

[Grandpapa-G]

    Update: the saga continues!
After the last post I looked carefully over all the results since I started on the autosense 10 on Sept. 25 2019. The upward drift after the bathroom break did show up from the beginning but was not always present - no ramp was ever used. In March and April I was preoccupied chasing leaks with my P30i mask. As my hair grew longer due to the covid closures I began to have problems stabilising the mask so I ignored the pressure pressure drift for the time being. After staunching the leaks using bobby pins to immobilize the mask, I decided to contact my cpap supplier (#34) regarding a potential warranty issue as the pressure was drifting for no apparent reason. They agreed to replace the machine once I sent them mine. Three weeks later, on June 4, I received a new machine (but it too exhibited the same problem). I then sent an email to Resmed asking for help with the issue. I also reverted to my old P10i mask as the bobby pins were causing early morning irritation leading to brief arousals. With the P10 mask the drift were not present but I cant believe that the mask change made a difference. I also do not believe that my two machines were both malfunctioning - I am baffled! does anyone have comments / suggestions (while I await word from Resmed).

[OpalRose]

I don't see anything in your graphs that would indicate a problem with your machine.

On another note, have you tried turning the EPR down to 1 or even off to see if that clears up the Clear Airway events?

[Dormeo]

I am not seeing a drift here. Could you say more about what you think these charts show?

Also, I wonder whether you might try reducing your EPR from 3 to 2, to see whether that reduces the number of CAs. I know you've said you simply take long pauses between your breaths, but the zoomed-in view doesn't really show a series of breaths with long pauses that include some over the 10-second mark.

[Dormeo]

Ah, when I posted I hadn't seen Opal Rose's post. I recommend that you follow her advice and trying turning the EPR down to 1 or 0, rather than to 2 as I had suggested.