Non-Vented Masks

[stcrim]

Has anyone ever used a non-vented mask to increase Co2 or to prevent it from washing out and causing more CAs?

[SGearhart]

No, is the easy answer. If a mask wasn't vented, it would sound like a "Whop-Pee" cushion every time you exhaled. Another consideration is if the airflow was blocked a secondary air path is needed for protection. . . Of course this is just my opinion.

[chunkyfrog]

If you have been reading about eucapnic breathing, please re-read the parts published by
legitimate medical sources--especially read the part about how doing it on your own can KILL YOU.

[stcrim]

Non-Vented masks are used regularly in hospitals: http://www.resmed.com/int/products/hosp ... nc=dealers

Cpaps tend to wash out the needed Co2. I'm not talking about added Co2 just preventing it from washing out which would be increasing it over regular Cpap Co2 content.

[archangle]

This is really dangerous if you don't know what you're doing. Just using a non-vented mask could kill you because you'd be rebreathing your exhaled air over and over. You need an exhale port of some kind.

I hate to see people discussing this because someone will try it and do it wrong and die.

What were you planning on doing?

[stcrim]

This is a commercial, use at home non-vented mask: Mojo® Full Face Ventilation Mask. I think it has to be safer than that our they wouldn't be readily available: http://www.sleepnetmasks.com/respirator ... face-mask/

[Slartybartfast]

From ResMed:

ResMed’s non-vented masks are
suitable for patients suffering from
acute as well as chronic respiratory
distress or failure. The masks are
specifically designed to be connected
to ventilators that use an active
exhaust valve and/or breathing circuit
with an exhaust valve."

It looks like they're used with dual-limb ventilators. One hose supplies pressurized air, second hose takes exhaust air. The technical info on these masks frequently refers to "low mask internal volume to minimize re-breathing exhaled air."

[stcrim]

Slarty - thank you!!!

So how does one prevent or slow Co2 washout that contributes to CAs? When I restrict my nostrils to 4mm holes with waterproof tape (using a Wisp mask) my medium respiration rate comes down from 17 or 18 to 15 or 16 and the CAs disappear. My AHI drops from close to or above 5 to -0- or just a little above.

Without the tape, the more pressure the more CAs - the less pressure the more obstructives.

The problem with what I am doing is the tape becomes annoying during the night and becomes a source for awakenings.

[archangle]

No, is the easy answer. If a mask wasn't vented, it would sound like a "Whop-Pee" cushion every time you exhaled. Another consideration is if the airflow was blocked a secondary air path is needed for protection. . . Of course this is just my opinion.

No, when you exhale, some of the air goes back up the hose, even if you have an exhale vent. Try putting the hose in your mouth and turning the machine on. You'll still be able to exhale. The fan in the CPAP machine generates pressure, but air will still flow backwards through the machine.

You definitely need some way for the CO2 to escape or it will build up and you'll end up with no O2. Otherwise, it's like breathing into a paper bag.

[archangle]

This is a commercial, use at home non-vented mask: Mojo® Full Face Ventilation Mask. I think it has to be safer than that our they wouldn't be readily available: http://www.sleepnetmasks.com/respirator ... face-mask/

No. Put that on a normal CPAP machine and you could die from lack of oxygen. Although, you'd probably get the feeling that you couldn't breathe and would have to take it off. However, in a low O2 environment, it is possible to lose consciousness from low O2 before you realize something is happening and then die from lack of oxygen.

[chunkyfrog]

Obsessing over CO2 can NEVER BE HEALTHY.
PLEASE stop doing it.
Do not futz around with what works already.
If you want to " hop" something up, make a vacuum cleaner actually WORK!

[Slartybartfast]

If CAs are a problem, it's likely that your pressure is set too high. My pulmonologist and I got into a long discussion about CAs. He said when he was in training, they'd anesthetize a rabbit, intubate it, and watch what happened as O2/CO2 blood levels changed. When O2 levels were above a certain level, the rabbit would simply stop breathing (a CA). There's also a reflex called Hering-Breuer that plays into this. Stretch receptors in the respiratory tract respond to over-inflation by temporarily inhibiting inspiration. Hence, a CA. That's why I say it's likely your pressure might be set too high. Too low, and you'll have obstructive events. Too high, and you'll have clear-airway events, such as a CA.

I really wouldn't mess with re-breathing if I were you. There are limits to what we as patients under therapy should do.

What is it they say? "A little bit of knowledge can be a dangerous thing?" "Someone representing himself in law has a fool for a client?"

[archangle]

If CAs are a problem, it's likely that your pressure is set too high.

Well, for some patients, you have to trade CA against OA. Sometimes you can't find an acceptable compromise and have to go to ASV or ST or T mode bilevel machines.

However, trying lower pressures and monitoring the OA and CA levels is worth a try.

stcrim, what CPAP model do you have and what is your pressure setting?

[stcrim]

Currently on a ResMed AirSense 10 Autoset. I have reduced my max pressure from 12 to 9 which did reduce some of the CAs but not a lot. I usually set the expiratory relief at 1 or 2. I am clearly a hyperventilator as perhaps all people with apnea (central and obstructive) are. Normal respiration should be about 12 but I'm way above that with and without taped nostrils. https://imgur.com/5ZQimP1

Restricting my inhale and exhale has been very effective for me but comes with the tape creating an annoyance that causes awakenings. Without the tape I get several CAs per hour on average which does not contribute to refreshing sleep. With the tape my AHI is -0- or just above and never have an obstructive - usually just a hypopnea or two.

[hyperlexis]

Currently on a ResMed AirSense 10 Autoset. I have reduced my max pressure from 12 to 9 which did reduce some of the CAs but not a lot. I usually set the expiratory relief at 1 or 2. I am clearly a hyperventilator as perhaps all people with apnea (central and obstructive) are. Normal respiration should be about 12 but I'm way above that with and without taped nostrils. https://imgur.com/5ZQimP1

Restricting my inhale and exhale has been very effective for me but comes with the tape creating an annoyance that causes awakenings. Without the tape I get several CAs per hour on average which does not contribute to refreshing sleep. With the tape my AHI is -0- or just above and never have an obstructive - usually just a hypopnea or two.

As the others have posted, this is playing with fire. If you have a serious problem with CAs then you need a proper physician advising you as well as, perhaps, a machine that better deals with centrals. A basic autopap machine plus an unvented mask setup is not a safe alternative.