[CPAP] ResMed full face mode vs. nasal mode

[adm1jtg]

DaveL -- from page 15 of the N20 user guide @ Resmed.com

Mask setting
options
For AirSense, AirCurve and S9: Select 'Pillows'.
For other devices: Select 'SWIFT' (if available), otherwise select
'MIRAGE' as the mask option

Since I use the AirCurve, I've been on the wrong setting for over a year -- oops.

Wow glad I saw this, silly me being new and having an aritouch 20 mask thats a "nasal" mask I set my machine to nasal.

But if the airtouch is supposed to be set to pillow then what would you actually set to nasal? Almost sounds like a conspiracy theory doesnt it 

[Sleepster]

You say that "With a nasal mask there is a greater restriction so the pressure delivered to your body is slightly less ...."  I would have thought that if you take the air pressure that's being delivered by the CPAP machine at its exit point and then concentrate it solely at the nose fitting, the recipient opening (the nose, of course) will suddenly get a larger hit of pressure than when that pressure was shared with the mouth.

Not pressure, flow. Or what the engineers call flow rate. Pressure is something entirely different.

It just so happens to be a textbook example of Bernoulli's Principle. If you have a fluid flowing through a pipe and the flow gets restricted, the pressure decreases. The flow rate increases, but the pressure decreases. It's also known as the venturi effect. (It was used to help the fuel pump feed gasoline into the now old-fashioned carburetor engines.)

This is exactly what occurs if you close off one output on any medium, be it water or air or whatever.

Yes, it is a perfect example of a drop in pressure accompanied with an increase in flow rate.

The engineering marvel of a CPAP machine is that it maintains a constant pressure over a wide range of flow rates.

[Gus Wah]

Great, and thanks for that.

[Sleepster]

But if the airtouch is supposed to be set to pillow then what would you actually set to nasal?

There are nasal masks that cover the nose (and not the mouth) as opposed to pillow masks that insert into your nostrils. The latter restricts air flow more than the former.

The old PRS1 machines had four "resistance" settings.

[adm1jtg]

but the n20 DOES fully cover the nose and not the mouth and is not based on pillows... its a mask.... thats why I was confused.

[DaveCar]

This thread has me wondering.
If the mask type setting changes the flow rate, and given that a person needs x volume of air over y time..
Does changing mask type affect our respiration rate, or our tidal volume ?

Perhaps mask type is not only a question of physical comfort, but also compatibility with your preferred breathing style ?

[Sleepster]

If the mask type setting changes the flow rate,

It changes the pressure. The flow rate depends on the mask design, the pressure, and the respiratory effort.

and given that a person needs x volume of air over y time..
Does changing mask type affect our respiration rate, or our tidal volume ?

Perhaps mask type is not only a question of physical comfort, but also compatibility with your preferred breathing style ?

Possibly. But I would think respiratory effort would have a much bigger effect on flow rate than the small pressure change caused by a mask-setting change.

[DaveL]

Gus Was I'm responding to your post...No 6

I think that buying a machine is like buying a car.  Talk to an "expert" and they'll recommend what they have.  Talk to a real expert and they'll ask questions about your use and needs.  Talk to a sleep doc and they'll recommend the machine they make the most money on, or have the best trip. And they want full control.

So my first two machines were Respironic bricks. That means they only reported hours of use.

And I didn't get a reporting machine until I bought one used from a friend who gave up on sleep apnea treatment and therapy.  I put 22,100 hours on that machine.

And I didn't get an apap until I learned to listen to people here.

I've had 2 Respironics machines (bricks) and two ResMed machines in 35 years.

Fast forward---Respironics machines have been cursed with a recall; there are no Respironics machines to replace them.  Interpretation---use at your own risk. And now they are having trouble supplying masks....

So my needs:
* effective treatment
* comfort
* ease of use
* low AHI (By the way my score was 43 over 35 years ago.)

I get more mental comfort using ResMed machines.  As long as I can download a card with my history on it. Respironics machines won't let me do that.  They can keep them.

My treatment started with no way to monitor my conditions.
So---if I realized that I felt like crap after a long while, I'd call my sleep doc. In about 2 weeks they would call me back and make an appointment for me. It was always 2 months away....He would ask several questions and 
* either increase my pressure by two units
* or make another appointment two months in the future....
* or tell me he didn't like my mask and suggest a change; and make an appointment for me with his DME supplier who only sold Fischer & Paykel masks....one type suits all
Observation....I still felt like crap

[Gus Wah]

DaveL, your comment leads me right back to my gospel: 

Nobody knows your body better than you.  The so-called professionals who advise apnea patients do love the money they are paid, but unfortunately they have no idea and little concern about what goes on in the air passages of every different patient.

I'm disappointed that so many others (like me) make the mistake of beginning this journey with the idea that we need to be hand-held by doctors.  Living with OSA is far from rocket science.  I'm also disappointed that I wasn't diagnosed 30 years ago when treatment, no matter how primitive, would have made those years so much better.

Onwards and upwards.

[DaveL]

Thanks Gus. I'm grateful for diagnosis 35 years ago. However, compliance meant wearing a mask with machine on for 4 hours a night. They didn't care of treatment worked. Could only measure AHI in a sleep study. And I went a long time without sleep studies. First two machines I had were bricks. Didn't measure anything except number of hours turned on....