Add a tube to the exhaust port?

Scarlet834 wrote:I appreciate this very detailed reply. I think you have all answered my question--no one has come up with something safe and effective for this. I'm sticking to the barrier method, I think, and probably not something attached to the mask.

DreamDiver wrote:

timbalionguy wrote:I have often wondered why no one builds a mask with two hoses-- one for pressure and one for exhaust. The pressure hose would be as we all use now, and the exhaust hose would run parallel to it, venting in a place away from the bed. A muffler could be put on the end of the hose, to silence the escaping air.

Today's masks all have CO2 relief valves for when power fails. Because of that short relief valve, if you sleep through a power failure you'll only be as likely to die from asphyxiation as you would without the aid of an xPAP. If the tube is long enough, your breath is shallow enough and the power is off, eliminating your Positive Air Pressure (PAP), CO2 buildup in such a system of tubes could depress your body's sensory feedback to the point that you won't even know you're asphyxiating - especially if you sleep through it. Putting it another way, if you keep your mouth closed (or wear a full face mask) a long exhaust tube will elevate your chance of asphyxiation well above untreated sleep apnea because you'll be rebreathing your own CO2 when your machine is without power. (You won't gasp because your body isn't getting the expected feedback. It can be very insidious. Cavers have to watch out for CO2 asphyxiation for the same reason.) Adding a muffler to the end, sad to say, is likely to cause even worse likelihood of asphyxiation, especially when there is no PAP to move the air. When there is power, a muffler will also change the xPAP response for the air column between your mask and your lungs, possibly throwing off your live titer on APAP, or causing odd results on CPAP.

I admit though - it does make one wonder why someone has not devised a three-way mask port: One that ports exhaust down a tube away from your partner when the machine is on, but opens a relief valve right at the mask when there is no PAP to keep such an exhaust port in exhaust position. It is likely due to two things: where do you add yet another hose on a mask and how noisy would it be?

I would strongly advise against jerry-rigging existing masks with exhaust hoses.
Please please please - do not attempt to create a long exhaust tube unless you really know what you're doing with the relief valve. With the swift, it might be easy to say "I'll probably just open my mouth if the machine goes off," but if your body is used to keeping its mouth shut, you may end up with a whopper of a headache during a power failure - or worse.