Why did my AutoCPAP 90% pressure increase from baseline?

[cchild2]

I’ve been using the Dreamstation Auto CPAP since mid September.  Except for the first night, there were no issues using it and my usage was high – the only days I wouldn’t use it was about once every two weeks when I’d fall asleep watching TV and not go to the bedroom.  I even took it on vacation.

The first three weeks in October I averaged a 90% cm H2O of 8.5 and an AHI of 3.1.  The next two weeks both were lower – 7.4 cm H2O and 2.3 AHI. 

Then on 11/8 to 11/11 I had 4 days of very high pressure (13.5cm average), where I woke up a lot and had difficulty going to sleep due to the high pressure.  I had to hit the ramp button often but the pressure would keep increasing.  Some of the days I turned off CPAP so I could get sleep. 

I realized that I hadn’t done anything with the filters, so I cleaned the larger filter with warm water (then dried it) and replaced the disposable filter.

The next three days were back to normal (11/12-11/14).

However, after that I was back to very high pressure (16.6 cm average), poor sleep, hitting ramp a lot. 

On the 19th after it ramped to high pressure as I was trying to fall asleep, I had an idea to remove the filter, which I did at 12:20 am.  After that I slept and had normal CPAP results until I put the filter back in at 5 am. 

I realize it isn’t good to remove the filter so I called to get another larger filter that I clean.  QMES said I only get a replacement for that filter every 6 months.  So I ordered some on Amazon.

The next night I had poor sleep and decided rather than turn the CPAP off, just remove the filter again (at 1 am).  Slept good after that.  (see attached pictures)

Looking at the data, I used to have very little VS and VS2 (vibratory snoring) and very little snoring (during the weeks when my 90% pressure was 7.4-8.5).   However, now when I’m trying to fall sleep (but still awake) I have high VS/VS2/snoring and the machine sees this and ramps up the pressure.  I’m awake so I know I’m not snoring!  I hit the ramp button and it starts ramping up again!

Attached are the sleepyhead pictures for last night.  You can see the times I hit the ramp button because the pressure was getting too uncomfortable.  At 1 am, I got tired of fighting the machine and not sleeping and removed the filters.  After that the CPAP data and my sleep were normal.  Thanks

As a new user, I wasn't allowed to post the pictures.
http://www.imgur.com/a/u0dRl
http://www.imgur.com/a/EeduP

Fixed links to imgur per Moderator.

[trish6hundred]

Hi cchild2,
WELCOME! to the forum.!
Hang in there for answers to your question.
Good luck with CPAP therapy.

[Walla Walla]

I'd return it and ask to try another machine.

[SnoringInOregon]

Looking at the data, I used to have very little VS and VS2 (vibratory snoring) and very little snoring (during the weeks when my 90% pressure was 7.4-8.5).   However, now when I’m trying to fall sleep (but still awake) I have high VS/VS2/snoring and the machine sees this and ramps up the pressure.  I’m awake so I know I’m not snoring!  I hit the ramp button and it starts ramping up again!

I also have a Dreamstation. I also sometimes have the same problems you do in terms of snoring.

I always have many VS2 events. Often they also start immediately after I put my mask on, long before I even fall asleep. The other day I had 56 events in 6.5 hours. The Dreamstation doesn't increase pressure much (if at all) when VS2 occurs. So I mostly ignore VS2 events; I've turned them off in my SleepyHead preferences (under Events) to keep them from cluttering my graphs. BTW I still haven't seen an easy to understand explanation of what VS2 events really are, even though people have posted a few links to attempted explanations.

The VS events are much different. If the machine sees them it is usually very aggressive in terms of increasing pressure. My worst experiences with VS events were for a few weeks in late summer when Oregon had a lot of smoke from forest fires.

The smoke particulates are so small they certainly pass thru the pollen filter and IMO they mostly pass through the fine filter. (BTW if you are sensitive be sure to buy genuine Respironics fine filters; I don't think the clones are as good). Has there perhaps been a recent increase in air pollution in your area? Maybe you are reacting to that.

Experiences are certainly individual. But I know I had a lot of stuffy noses when we had the forest fires. My stuffy nose caused VS events, which caused pressure increases, which caused discomfort because of the high pressure.

One way I coped was to limit my pressure range. My DME started me at 7-20. After a few months I changed to 8-15. But when I had the VS problems even 15 was too high. I reduced to 12.5. I'm now comfortable with 9-12.5

Of course my pressure settings aren't your settings. We're all different. But, based on the months of SleepyHead history I had before the fires, I knew what my max could safely be. Specifically in my case I had never gone above 12.8, and that was only for very short times. So I felt comfortable reducing my max to 12.5.

Hope that helps. Good luck.

[cchild2]

Snoring in Oregon - thanks so much for the great response. 

In particular, these were helpful:

The VS events are much different. If the machine sees them it is usually very aggressive in terms of increasing pressure.
My stuffy nose caused VS events, which caused pressure increases, which caused discomfort because of the high pressure.

I'm still learning how to live with machine and being an engineer, I love learning about how it works.

Lately with the changing seasons, there has been a no vacancy sign in my nose so perhaps that is a good part of the issue.  I have noticed that when the pressure is low (4-5) that it does feel like I'm not getting enough oxygen.  When I hit the ramp button, it goes down to 4.0.  Currently I'm in the Auto CPAP setting where it can range from 4-20.  I'd like to get the doctor to limit it to a more narrow range at my next appointment.  I'm thinking 6-10.  I have the good manual, so perhaps I'll change it myself

Last night I changed the disposable filter again and it was a great night as the pressure stayed moderate.  (I must admit the good night was also partly due to turning off my alarm clock) 

I look forward to understanding the sleepyhead data better.  Thanks for your help.

[Sleep2Snore]

I would just change the low pressure anyway.
Bring it up to where you get enough air to breath and you are not fighting the machine.
I used to find if I used the ramp function on my machine, it reached a point where I had to stop it as I was struggling to breath.
Once it got past that pressure and up to slightly higher pressure it was fine, asked doctor to put machine above the pressure on ramp and he said he couldn't, but that was a few machines ago when they were a bit lacking in functions.  I just had to hit the run button and forget about comfort starts.

I was told not to adjust my machine, it was not up to me to adjust it.  I think she implied I didn't know what I was doing!
I ignored her and shortly after I got it I was getting 0.0AHIs.
They will know I have adjusted it, but I will just point to the data

[yrnkrn]

Indeed, it seems like the low pressure is too low and the high pressure is too high for your comfort.
It is really important to be as comfortable as possible with CPAP treatment for it to be effective.
4-20 range is used short term to get indication and then you narrow/fine tune the range based on results.

I'm not sure the filters have anything to do with what you are experiencing, though.
At most, if really plugged, they will make the motor work harder, but not change the machine response to your breathing.

[OpalRose]

No one seems to know what VS2 snores are, except there seems to be some consensus that they aren’t really snores.  I turn that setting off in #SleepyHead.  It makes no difference in my data.

The VS are real snores, and the Phillips Respironics machines will raise pressure in response to VS snores, flow limation and Rera’s.

The thing is with your wide open pressure range, the pressure will rise almost to your max setting at times due to the snores, thus changing the 90% number.  You have to tame your machine so to speak.  Set a limit to the max pressure.

The bottom line is you should narrow your pressure range. Raise the minimum pressure to at least
6 and bring down max pressure to 14.

[cchild2]

Well, I changed my settings to 7-11 cm H2O and had a good nights sleep.  Nose is stuffy, so I had a lot of VS/VS2 events.  But my AHI was 0.38 over 6+ hours.

htt ps://imgur.com/a/wndr6

1 hypopnea event the whole night. 

OpalRose - at least in my case, I'm not sure even the VS are real snores, as I did them constantly throughout the night, even when I was awake.  I think it is just an artifact of my stuffy nose/mask I am using (Amara View FFM)

Looks like I need to review this board/FAQ for tips to help with clogged nose in winter time.  I do have a humidifier (I believe it is on setting 3) but no heated tube.

Thanks for everyone's help.

I'm half tempted to put the setting at 8-10, haha.  As long as I keep my AHI under 3.0 (or at least 5.0).

[jaswilliams]

Not sure what is going on as It was running at full pressure all night (11) I assume whatever it was counting as stores was causing it to keep the pressure high, Graphs look odd.