Pressure changes

[Crazytired]

Hello,
I have a couple of basis questions.
I’m on auto cpap, 6-12 cmH20. My 90% pressure is always around 10. My AHI is ~5 and I’d like to increase my pressure. Do I increase the minimum pressure? Does the 90% pressure mean that my minimum pressure needs to be close to that pressure to prevent apneas? or would I increase my maximum pressure? My pressure never goes higher than 11.
Thank you for your help.

[palerider]

Hello,
I have a couple of basis questions.
I’m on auto cpap, 6-12 cmH20. My 90% pressure is always around 10. My AHI is ~5 and I’d like to increase my pressure. Do I increase the minimum pressure? Does the 90% pressure mean that my minimum pressure needs to be close to that pressure to prevent apneas? or would I increase my maximum pressure? My pressure never goes higher than 11.
Thank you for your help.

The 90% pressure means nothing, it's used by people that can't understand a pressure graph.

The Max pressure should almost certainly be at 20.

The min pressure is probably too low, but without seeing data (as detailed in the READ THIS BEFORE POSTING sticky) we'd just be guessing.

[Okie bipap]

The 90% pressure means your machine was at OR BELOW that pressure 90% of the night.

[Miss Emerita]

Hello, Crazytired. You can get some good advice about your pressure settings from the experts here if you can post a Daily Chart from the Oscar software:

https://www.sleepfiles.com/OSCAR/

You will need a laptop or desktop, an SD card in your machine, and either an SD slot in your computer or an SD card reader that you can connect to your computer. Let us know if you run into any hitches with getting this all set up.

[Crazytired]

Thank you

[Crazytired]

Thanks for info on installing Oscar. I’m in the process of getting a new computer. But I have some generic questions if anyone can help with, as try to improve my understanding. Back to my 90% pressure question. At first I thought it was used to adjust the minimum pressure. But it seems to guide the consideration of the max pressure. The mean pressure seems more aligned with what the min pressure should be. When I go for my sleep medicine checkups they refer to these and I’m trying to understand. I know when my AHI is up, the min pressure is increased. Is there a difference in treating hypopneas vs apneas in terms of which pressure to increase, the max or min? I know these are such basic questions but I’m made progress that I can identify some of my confusions and formulate the questions now.
Thank you so much for your help.

[D.H.]

I recommend that everybody set the max pressure to the machine max, unless one of the following are true:

1. You are experiencing central (or “clear airway”) events at the higher pressures (and not so much at the lower ones).
2. The higher pressure is causing leaks or discomfort (including waking you up).

[Julie]

The point is that it's the min. setting that does the work... most are able to leave the max pressure at e.g. 20, or not a lot lower. So if you want a lower AHI you'd raise the min. pressure by a couple, but leave the max alone except under particular circumstances when it might be advised. Hypopneas are a bit like mini apneas, so more pressure usually helps with them.

[Pugsy]

Back to my 90% pressure question. At first I thought it was used to adjust the minimum pressure. But it seems to guide the consideration of the max pressure.

No, the 90% pressure has nothing to do with max pressure setting.

The 90% pressure number is just a number that reflects where the pressure was AT OR BELOW for 90% of the night. That's it...nothing more and nothing less. It is easily skewed to the high side by relatively short periods of time at higher numbers.

Is there a difference in treating hypopneas vs apneas in terms of which pressure to increase, the max or min?

Minimum pressure settings is the most critical setting. It does the bulk of the job of holding the airway open in the first place so that OAs or hyponeas don't get a chance to materialize.

You want a minimum pressure high enough to hold the airway open for the bulk of the night and be close enough to where the pressure might want to go if something happened to cause a need for more pressure on a short term basis (supine sleeping or REM maybe).

The maximum pressure setting doesn't do much except maybe limit where the machine might want to go for some reason.
Normally we limit it only if the going higher creates a big problem....like aerophagia or centrals or really disturbs sleep for some reason.

[palerider]

Back to my 90% pressure question.

No, 90/95% pressure to is MEANINGLESS!. All it is, is a max pressure with brief peaks clipped off. It's a statistic, nothing more than "oh, look at that".

At first I thought it was used to adjust the minimum pressure. But it seems to guide the consideration of the max pressure.

No again, the 90/95% number is completely meaningless!

The max pressure should me left at 20 (or 25 on a bilevel) unless there are compelling reasons to lower this.

The mean pressure seems more aligned with what the min pressure should be.

No, the min pressure should be set above the point where events repeatedly cause the pressure to spike up. Trying to use some statistical number to set min pressure is something intellectually lazy or ignorant people do.

When I go for my sleep medicine checkups they refer to these and I’m trying to understand.

you don't need to understand people that babble about inconsequential things.

I know when my AHI is up, the min pressure is increased. Is there a difference in treating hypopneas vs apneas in terms of which pressure to increase, the max or min?

MAX pressure never increases, it's an operational limit, which is why lowering it does nothing useful, it only prevents the machine from responding to your needs. About the only time max should be reduced is if someone has issues with aerophagia, then it's a delicate balancing act between getting enough pressure to prevent events but not so much as to cause pain.

[palerider]

I recommend that everybody set the max pressure to the machine max, unless one of the following are true:

2. The higher pressure is causing leaks or discomfort (including waking you up).

NO! , The answer is to *fix the leaks*

[kotell]

Hey Everyone - new to cpap trying to get used to it i'm upping the pressure slowly, so now i have a min pressure of 5.5 and max 7 (sleeping with a oral appliance as well planning to remove when machine manages my apneas)

my sleepyhead pressure graph dose not show that it was at max 7 during the night when even though my result was 5.91 AHI why is that?

Thank you

[Pugsy]

Hey Everyone - new to cpap trying to get used to it i'm upping the pressure slowly, so now i have a min pressure of 5.5 and max 7 (sleeping with a oral appliance as well planning to remove when machine manages my apneas)

my sleepyhead pressure graph dose not show that it was at max 7 during the night when even though my result was 5.91 AHI why is that?

Thank you

You might want to start your own thread/topic.
Please read this.
viewtopic/t172378/Sticky--Newbies-PLEAS ... STING.html

[palerider]

And by "might" she means "do".