Q: What is 90% Pressure?

[LanceC]

These readings are clear to me except the 90% Pressure. What exactly does it mean?

Avg Pressure 17.97
Min Pressure 10.18
Max Pressure 19.60
90% Pressure 18.48

Thanks!

[eseedhouse]

These readings are clear to me except the 90% Pressure. What exactly does it mean?

Avg Pressure 17.97
Min Pressure 10.18
Max Pressure 19.60
90% Pressure 18.48

Thanks!

It means that 90% of the time your pressure was at or below 18.48

[LanceC]

It means that 90% of the time your pressure was at or below 18.48

Okay, that makes sense. Why do we care?

[truetopath]

If you're trying to hone in on your pressure requirements the 90% figure is helpful.

[LanceC]

So it's more important to know I spend most of my time below 18.48 than that I occasionally hit 19.60...

I occasionally have trouble at high pressure getting a lot of leaks. Setting my top pressure down to 19 might be a reasonable way to deal with that.

[Napmeister]

I occasionally have trouble at high pressure getting a lot of leaks. Setting my top pressure down to 19 might be a reasonable way to deal with that.

Trying to think of a short way to address that ... here is a good link that will tell you a lot.
http://www.apneaboard.com/forums/Thread-...Discussion

Scroll down to #8, the section that is about 'Leaks'.
..looks like this:

8. Leaks (Done---except maybe add an example of an APAP line that shows the change in Total Leak as the pressure goes up?)
Difference between Total Leak Rate and Leak Rate
Definition of Large Leak
Perfect Leak/Total Lines
Good and Decent Enough Leak/Total Leak lines
Problematic, Bad, and Horrible Leak Lines
Mouth Breathing and Other Causes of Leaks
Annoying Leaks
Why are Large Leaks an Issue?

[OMyMyOHellYes]

It would be useful to know if you were wanting to set up something like a fixed pressure CPAP setting.

You probably are not going to ever eliminate 100% of events 100% of the time.

I set my CPAP at my 95% level (ResMed reports 95%). What I had titrated my old S-8 to based solely on how I was feeling just worked out to be my 95% pressure when I first got the S-9 and found the 95% number...

I believe it's kind of like a rule of thumb for estimating.

I believe it's getting late.

I believe I will finish my drink and go to bed.

OMM

[surferdude2]

Standard engineering and common sense normally consider anything less than 10% as being negligible. The 90% figure being discussed is taking that into account and the meaning would be to give little weight to any readings above that level when making decisions about your therapy setting. As for ResMed and their 95% reading, I consider it a bit too critical but perhaps they are taking into account the inaccuracy of their particular equipment and imposing a more stringent requirement than usual to compensate.

[Sleeprider]

So it's more important to know I spend most of my time below 18.48 than that I occasionally hit 19.60...

I occasionally have trouble at high pressure getting a lot of leaks. Setting my top pressure down to 19 might be a reasonable way to deal with that.

Lance, the 90% pressure is often used as the titrated pressure in CPAP therapy where only one pressure is used. For those using APAP, it is usually a good idea to set the MINIMUM pressure at least at the average pressure. In your case this puts the machine near your necessary therapeutic pressure more quickly. By having a low starting pressure, the machine may run higher pressures than needed as it over-shoots due to the many flow limits or snores.

The 90% is not so helpful as a guide to maximum pressure, but it does suggest where you most effective CPAP pressure might be. CPAP mod4e can be less disruptive to sleep for some users, and it avoids pressure swings that can initiate leaks.

My recommendation for you is either to stay with APAP mode with a minimum pressure equal to your current average pressure, or switch to CPAP mode and use the 90% pressure as the min/max pressure, with the objective to optimize comfort and treatment.

[LanceC]

Thanks!

I have an appointment with the Dr. next week. I'll suggest these changes then.

Since I just started therapy a month ago I don't think I'm ready to make changes myself yet.