Why won't cpap raise the pressure?

[AMK]

I was looking at the last couple weeks on Sleepyhead and discovered that last Tuesday I went for just over an hour with an AHI of 51.59. My cpap is set to 7.4 - 16, which most of the time works fine. But I have never seen the pressure go above 14 in Sleepyhead. Why do you suppose the machine let me go on for an hour like this without raising the pressure? There were no leaks.

Here's a gyazo, sorry I just can't remember the official way to embed a pic:
https://gyazo.com/d7a988855ea75c2599152766411bfd4e

[palerider]

I was looking at the last couple weeks on Sleepyhead and discovered that last Tuesday I went for just over an hour with an AHI of 51.59. My cpap is set to 7.4 - 16, which most of the time works fine. But I have never seen the pressure go above 14 in Sleepyhead. Why do you suppose the machine let me go on for an hour like this without raising the pressure? There were no leaks.

Here's a gyazo, sorry I just can't remember the official way to embed a pic:
https://gyazo.com/d7a988855ea75c2599152766411bfd4e

Looks to me like your machine is actually set to a max of 14, but since you only showed part of the screen, that's just a guess.

[AMK]

https://gyazo.com/7f365dc5f48a53814727412061ab8e02

16.

Here is the whole screen, if that helps:
https://gyazo.com/ecc75f28a6a035651f669523e308c09d

Thanks.

[LSAT]

What happened between 2:30 and 3:30AM ? Were you up, were you restless, were you fast asleep, did you have a nightmare??????????
What do the individual events look like? Are they short or long?

[AMK]

LSAT I should have just been sound asleep. Since it was a week ago I don't remember specifics, but it would be unlikely for me to be awake at that hour. The events seem to range from 10 seconds to 36. I just wondered why on earth the machine didn't take the pressure higher. It's not unusual for me to have a bad 15-20 minutes once in a while, but over an hour?

[ChicagoGranny]

Why won't cpap raise the pressure?

1. That's puzzling.

2. I would (and do) set the max at 20. Then see what happens.

3. At least for that night, the pressure went quickly to 9 and stayed at or above 9. Check if it's at 9 or above 9 most nights. If so, I would set the min to 9. Hopefully, this won't cause tolerance problems since the actual pressure is running at 9 or above already.

4. Click on the events tab and see how long those apneas are.

5. Have you tried reducing the EPR or even turning it off? I find the pressure changes on each inhale and each exhale are disturbing.

[Pugsy]

That is very odd indeed.
Does this happen very often where you see very dense clusters like this and the machine has ample opportunity to increase but doesn't?

Do confirm that the max is 16 by going into the machine setup menu and checking. Sometimes SH gets a little confused when reporting settings. Just to make sure that the max is 16. It probably is but it's something we need to verify for sure.

If that is the case...something must have been missing from the needed requirements for the machine to want to go higher but I can't imagine what it might be unless these were centrals/CAs and they are clearly flagged as OAs.

Your night was textbook perfect otherwise but for sure major ugly when it happened. There is a rather complicated set of conditions that need to be met for the machine to increase the pressure. I don't know all the particulars involved and time is one factor but an hour is ample time.

[zoocrewphoto]

It doesn't show many flow limitations during that hour of events, and that is what the machine usually uses to determine that it needs to raise the pressure. That seems really odd that they would drop off at exactly the time that you get worse.

Also, the settings say max of 16 on the left, but the pressure line looks like it is bumping against a maximum of 14.

Both things look odd to me. Possibly a machine problem or a data problem. If it were me, I would check the data in ResScan to see if it is the same. I would also reboot the machine and raise the max pressure to make sure it really can go above 14 or even above 16. If the problem continues, I would wonder if there is a problem with the machine detecting flow limitations and/or maintaining the correct settings.

[AMK]

Pugsy, yes, it happens regularly. Usually it's just for 20 minutes or so. Here is another example:
https://gyazo.com/244c32fae003369732a5e93f6d381bdb

It simply refuses to go above 14, and it never has. I just went into the clinician settings and yes, the machine is set for a max of 16.0. The last time I saw my sleep nurse, last December, I asked her about this, because I am worried that there is something wrong with the machine, and she simply announced that it was obviously Sleepyhead misreporting the data. I asked the DME and she linked to the wireless connection and said it was fine.

ChicagoGranny, I can raise the max. I am reluctant to raise the min because I found that raising it higher is too startling and I have trouble falling asleep. I hate the ramp because when it starts at 4 I feel like I can't get enough air. At 7.4 I just go right to sleep.

Zoocrewphoto, right, that's how it has always looked to me, like the machine thinks the max is 14. I did not know that the machine could be rebooted. I'll look into that and load the data into ResScan. Thanks for all the ideas!

[Pugsy]

Flow limitations are just part of what these machines are supposed to increase the pressure in an effort to kill them.
Flagged OAs and hyponeas are also part of what the algorithm will try to kill. So they don't necessarily have to have FLs for the machine to respond.

[Gryphon]

one side note - it may be nothing but, Are you using a inline bacteria filter?
If they get really dirty they can lower the delivered pressure to the mask - which would cause apnea to not be treated properly and grow worse. With the built up pressure on the other side it and the filter acting as a muffle could interfere with the machines ability to detect events and compensate.

Just a thought. If your not using such a filter then continue with the other posters advice and keep checking. Very odd.

Best of luck!

Gryphon

[Pugsy]

I doubt very seriously if SleepyHead is making all this up...but probably should verify with ResScan.
Let me know if you can't find it via private message.
Windows only software though.

Your most recent example looks like REM or supine sleeping cluster.

Now here's the deal...I think anyway...the machine won't increase the pressure during the apnea event (OA or hyponea) instead it waits until the airway opens back up and decides what to do. Now why it isn't seeing the need to go higher with all this going on...I don't know.
There's enough time between events I would think or at least some of them.
The last ones are about a minute apart.

Have you tried increasing the minimum?

[AMK]

OK, ResScan verifies. This shows the same max pressure that Sleepyhead shows:
https://gyazo.com/3dc01a001edbc18f097d33599f07ae55
And this shows the events:
https://gyazo.com/bdd66a24e4d20568578bdf1ed7fee9e7
It all looks the same as in Sleepyhead.

I do not have an inline bacteria filter.

I have played with the minimum myself over time, and I have to be careful or the centrals start creeping up. Most of the time my nights look good in Sleepyhead. But on a night like this one the machine doesn't help.

I turn the machine off when I get up in the morning. Is there an off that is more off than that for a reboot? I see I can reset it to factory defaults and start over.

[Pugsy]

I think I would
1...totally unplug the machine from the wall..30 seconds is sufficient
2...plug it back in
3...go do the reset to factory defaults thing..
4...reset it again like you have it and see what happens.

This covers all potential bases...

[AMK]

OK I'll do that.