Long term nasal user, basic issue when trying full-face

[DanPrado]

Hi, sorry for such a basic question tried the search feature but this does not seem to be a thing, which makes me think I am doing something fundamentally wrong.

Been benefiting from CPAP for over 5 years, nose breather and always used nasal but lately finding myself doing weird mouth things, particularly since I prefer sleeping on my back.  

Figured I would try a full face mask and bought an AirFit F30i since I've been loving the AirFit N30i since it came out.  

As hoped the fit works fantastic for me and the mask feels comfortable, slept for a few hours and then had to go back to nasal -  every time my mouth would crack open the air would make my mouth / cheeks would blow like a blowfish.  Tried breathing through my mouth no difference.  I can't imagine this is normal.

My CPAP is a Dreamstation and I've had the Mask Type setting to OFF for years since I learned here that it does not apply to ResMed masks.   So I made NO settings changes at all between the F30i and the N30i.    Is this the problem?

Other than that I noticed that the auto-start feature would not work with the full-face, so I had to push the button to start the air-flow - does this indicate a problem?

Thanks in advance!

[Hydrangea]

Regarding the auto-start:
I have found that I don't have a strong enough exhale/inhale to trigger the auto-start with a FFM.

Regarding the sudden mouth weirdness:
I experienced the same thing after some time using P10s. I thought my body had unlearned how to nose-breathe. After much experimentation and observation, I've learned it wasn't me it was the mask! For me, the P10 either wasn't or it began not venting well, so I was rebreathing my exhaled air, which my body was rejecting and thus side-stepping by opening my mouth to breathe clean air.

I am now experimenting with modifying the vent on my P10, to help it vent better. I'm hopeful this will work for me. (Obviously this wouldn't be recommended as medical advice. I'm just sharing my experience.)

[DanPrado]

Thanks, that's an interesting observation, wonder if that may be the case for me too.

I think that if I can figure out the full face that could still make things good again, and my wife also commented on how quiet my exhale was during the few hours that I wore it.

Eager to hear ideas on tackling the "blowfish" issue.

[DanPrado]

Update: I just experimented setting the mask mode to 1 (which would make it more like the Dreamwear offering), switching from C-Flex to A-Flex to No Flex, plus the various Flex values.

It makes zero difference, as soon as I open my mouth and pretend to breathe from it the air pressure just fills my mouth and inflates my cheeks in a really uncomfortable way, just can't imagine this is what full-face users are going through!

Lowering the pressure may work but then that would likely impact the benefit.

Any other setting ideas that I should try?

[Hydrangea]

Have you tried the tongue suck trick? That's the only way I'm able to keep the air from going in my mouth.

[SarcasticDave94]

I think either sealing your mouth off via the tongue suck method to stop the mouth being an airway or open your mouth a bit in a pursed lips method people like myself use to mouth breathe. I have COPD so I mouth and nose breathe with mask off. I think the blowing up your mouth is due to not completing the airway circuit. You're letting pressurized air to leak in from the throat but probably aren't opening your lips to release the air into the mask.

[DanPrado]

Thanks for both replies - I was not aware of a tongue method, will search the forum to learn more.

To clarify everything is fine if my lips are sealed, the issue is when I unseal my mouth incoming air rushes into my mouth.

[OpalRose]

This is where practicing the tongue seal trick will come in handy.


Tongue Suck Technique:
Place your tongue to the roof of your mouth with tip of tongue behind front teeth.  Slowly suck upwards and back.
This places the tongue in a natural position, with the back of tongue sealing the back of the throat so that if you open your mouth/jaw while sleeping, no air will escape.

[DaveL]

Regarding the auto-start:
I have found that I don't have a strong enough exhale/inhale to trigger the auto-start with a FFM.

Regarding the sudden mouth weirdness:
I experienced the same thing after some time using P10s.  I thought my body had unlearned how to nose-breathe.  After much experimentation and observation, I've learned it wasn't me it was the mask!  For me, the P10 either wasn't or it began not venting well, so I was rebreathing my exhaled air, which my body was rejecting and thus side-stepping by opening my mouth to breathe clean air.

I am now experimenting with modifying the vent on my P10, to help it vent better. I'm hopeful this will work for me.  (Obviously this wouldn't be recommended as medical advice.  I'm just sharing my experience.)

This is a wonderful explanation Hydrangea!

I'm using a ResMed N20; I wonder if that's the reason I mouthbreath? Thanks for your post.

[DanPrado]

I just did a forum search for "chipmunk cheeks" and found lots of useful information, what a great resource this site is!

I already tested a few things and eager to see what tonight will be like.