[CPAP] ResMed full face mode vs. nasal mode

[Gus Wah]

I've been trying to tune in my mask choices.  I'm currently on the N30i.  

Nobody I've communicated with knows the answer to this, but maybe somebody here does.  What does the AirSense 10 do differently when a user selects "full face" mask versus "nasal" mask?

I'd be delighted to hear from anyone who might know this.

With thanks....

[Dog Slobber]

ResMed doesn't document how therapy changes when changing the mask setting. Based on discussions I've read, the mask setting influences pressure and mask leak calculations.

[Gus Wah]

ResMed doesn't document how therapy changes when changing the mask setting. Based on discussions I've read, the mask setting influences pressure and mask leak calculations.

Well, yes, I've known this.  What I was looking for is someone who has the answer.

[Expat31]

I would like to know also, I guess it may change air volumes to mask, say less to a pillows mask, and more to a full face mask? Air pressure is obviously delivered from separate settings.
The equipment supplier technician says he thinks unimportant, but not convinced with answer.

[DaveL]

Welcome to the forum! I'm Canadian too. I don't have a good answer. However, maybe my experience will help you reach a decision. I doubt whether ResMed will answer your question....

I have the s10 auto sense for her machine. I've used the ResMed N20 nasal mask for some time. I was recently told by a member here that ResMed says to use the "nasal pillows" setting for my mask. I had used the nasal mask setting continuously with about 4 different N20 masks.

I changed the setting to nasal pillows; I haven't noticed any difference in treatment.

My thought--I should have checked the setting when I first used the mask. If ResMed thinks it's important enough to specify it, I should have done it.

I recently purchased the N30i mask and tried it for a week. My results were terrible. I'm back using the N20 mask.

I've been compliant for over 35 years. I find that mask selection is really tough lately. The hardest thing for me is getting a good fit, without leaks.

Suggestion--you will make great progress asking questions of the skilled people here. My treatment improved a lot when I downloaded OSCAR and posted the results here. I needed more experienced help to move ahead and improve my treatment.

[Gus Wah]

Great comment, DaveL, and thanks.

I only began CPAP therapy six months ago, and I'm completely compliant. Actually my life depends on it since remaining undiagnosed with critical OSA led to a stroke that occurred during my numerous apneas. BTW my sleep study revealed an AHI of 45. It was obvious that I've been oxygen deprived during sleep for a very long time.

My question regarding the ResMed settings (nasal or full face) is simply one of discovery since I'm trying to end a problem with oral exhalation. I am NOT a mouth breather. But I have not been able to figure out why when I inhale (through the nose, of course), not all the air makes it to my lungs. When the pressure reaches about 13 and higher I start having spurts that want to exit via the path of least resistance -- that would be the mouth.

I now have three masks. Two of them are "full face", although I don't know why the Respironics is called that with no covering on the nose at all. My hope is to wear only the ResMed N30i, but the mouth spurts prevail. Last night I threw my hands in the air and went back to my AirFit F20. It's more cumbersome, but at least there are no leaks.

I'm really on my own with CPAP therapy. I did consult with respirologists at first, but it was clear they only make general suggestions, and only by phone. In the end, I'm not convinced those people know more about my air passages than I do, nor do they care. I've used OSCAR all along, and I think it's amazing. I've been able to bring my AHI down to approximately 0.4. But if I go back to the nasal mask, I'm fraught with the oral exhalations. The AirSense 10 reports these as major leaks and my AHI jumps up to 3 or so. It also means a night of very poor sleep.

Apparently I'm not alone in my discovery that ResMed's clarity leaves a lot to imagination. I can't imagine why they'd even bother providing a selection in the software if it doesn't make an appreciable difference. I could list several more of my complaints with their products, but let's just say that if a competing machine were to enter the market, I'd probably be among the first to buy it.

[DaveCar]

There cant be much of a change in air delivered via whatever setting, as this is the air going into our lungs.
Per individual, there is a need for x volume of air over y seconds.
I assumed that the mask settings change things like the sensitivity for switching exhale relief mode and for event detection ?

FWIW, I love my F30. I set the headgear so that it's pulling up on my nose a bit more than 'normal' which helps keep my nasal passages open. If my yap happens to open during the night, I still get therapy.

[Rich66]

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.

[Sleepster]

When you set the pressure on your machine, that is the pressure delivered to the machine end of the tubing. But what is the pressure  of the air that enters your body through the mask? It will be slightly different depending on the amount of flow restriction provided by the mask. Full face masks offer less resistance than nasal masks because they have a bigger opening. They cover both nose and mouth. The nasal mask versus full face mask setting on the machine is an attempt to compensate for this difference in flow restriction.

With a nasal mask there is a greater restriction so the pressure delivered to your body is slightly less than it would be if you had a full face mask. Thus changing the setting on your machine from full face mask to nasal mask will raise the pressure slightly. How slightly? I don't know. Less than 1 cm I think. If you have a machine that auto-adjusts the pressure (as opposed to a fixed pressure machine) it will automatically take care of the problem. Those are the reasons that the setting really doesn't matter that much.

The older PRS1 machines (Philips Respironics System One) had a "resistance" setting and if you had a Philips mask it told you which resistance setting to choose. If you had some other brand you had to make an educated guess. So I think it was largely a marketing gimmick to get you to buy Philips masks. Then of course ResMed had to follow with their own resistance setting scheme and I think that's how the full face vs. nasal mask setting came about.

[Gus Wah]

Thanks, Sleepster, and that makes the matter a lot more sensible.

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

Just trying to understand the logic.