Non-Vented Masks

General Discussion on any topic relating to CPAP and/or Sleep Apnea.
User avatar
LSAT
Posts: 12761
Joined: Sun Nov 16, 2008 10:11 am
Location: SE Wisconsin

Re: Non-Vented Masks

Post by LSAT » Tue Sep 08, 2015 4:52 pm

I agree you are taking dangerous steps. If the CAs are clear airway events you are causing a higher AHI by reducing your upper pressure. Pressure doesn't affect CAs if they are Clear Airway events. The charts that you posted in previous posts do not indicate a serious CA problem.

_________________
Machine: ResMed AirSense™ 10 AutoSet™ CPAP Machine with HumidAir™ Heated Humidifier
Mask: Fisher & Paykel Vitera Full Face Mask with Headgear (S, M, or L Cushion)
Additional Comments: Back up is S9 Autoset...... Buckwheat hull pillow

VisitorX
Posts: 2
Joined: Mon Oct 05, 2015 1:36 am

Re: Non-Vented Masks

Post by VisitorX » Mon Oct 05, 2015 2:51 am

This post is based on my current understanding, which could change and should be verified by independent sources. With that caveat, I'll proceed.

The issue the person is experiencing falls under the category of "complex" sleep disordered breathing, which is estimated to affect a not-insubstantial minority (some say as high as 20 percent, others give lower numbers) of patients with sleep apnea. Complex SDB is not well understood by the majority of sleep doctors, who don't know how to recognize it on a PSG and keep throwing CPAP at patients and then accusing them of being non-compliant when it doesn't work out. Complex SDB refers to people who appear to have typical OSA (that is, plain-vanilla obstructive apneas) but when they are subject to the pressure of CPAP, they start to experience central apneas and/or hypopneas. Google complex sleep apnea and you'll find plenty about it. I see that some people are now calling it "treatment-emergent central sleep apnea"--which seems like a more descriptive name--and you could probably google that, too.

Regarding the issue of CO2 and non-rebreathing masks, the objective, again as I understand it, is not to have a totally unvented system, but rather to displace the venting valve slightly further from the patient, so that instead of the venting taking place at the mask you now have a non-vented mask but a venting valve just a touch further down the tubing. This increases the "dead space" in the system--essentially, the amount of rebreathed air--and thus raises the level of inspired CO2. As the level of inspired CO2 increases, the level of CO2 gas in the body (usually quantified as PCO2) increases. Since even a small elevation in PCO2 can stimulate ventilation (under normal circumstances, an increase in CO2, not a decrease of O2, is the major driver of ventilation; it is CO2 that makes you feel air hunger when you hold your breath), the approach makes sense physiologically. Note that the objective is to raise the level of dissolved CO2 gas in the body (PCO2) very slightly, as that is all that is needed. We're talking about increasing dead space by something in the 50-150 ml range (i.e., 1/20th to 3/20th of a liter; which seems even smaller when you realize that tablespoon holds 15 ml). We're not talking about a totally closed system.

The full text of the original major journal article on this subject (from 2010) can be found here:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3014237/

A more recent article (from 2014) by the same person revisits this issue and also discusses other approaches. The full text is here:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3998090/

Another article by the same person from 2013 focuses on much the same issues but since the title contains the words "complex sleep apnea," I'm guessing (purely a guess) that the article may cover some of the basics more systematically, though I've not seen the article myself. This article is not available free on line (that I can see) but the abstract (introductory summary) is worth reading:

http://www.ncbi.nlm.nih.gov/pubmed/24136715

You can probably get a copy of the original article for free of for a small fee from the local library by speaking with the interlibrary loan specialist. They can usually get print outs of journal articles. But the abstract itself is very informative and it emphasizes that a key tip-off to the presence of complex SDB/treatment-emergent CSA is that the apneas and hypopneas tend to occur during non-REM (NREM) sleep, i.e., not during REM sleep (= more or less, dream sleep), which is when obstructive apneas tend to occur (because sleep paralysis, and hence airway flacidity, is most prominent during REM sleep).

Though all this is very promising, I'm not sure what the results are in terms of efficacy of treatment. If I'm not mistaken the author of the above-linked articles has found that simply increasing CO2 (via increasing dead space or by any other means) does not completely normalize breathing, and he is now using additional approaches, though I believe that increasing dead space has provided some, albeit incomplete, benefit.

This subject is complex but if you start googling and try to struggle through the journal articles you'll certainly learn a lot about the subject and, sadly, probably know much more than most sleep doctors, who seem incapable of recognizing or thinking intelligently and physiologically about complex sleep apnea. If you have complex sleep apnea, you'll really need to shop around and find an exceptionally well informed and thoughtful sleep doctor--a "thinker." Or you can try to see the doctor who wrote the above articles, in the Boston area.

I don't mean to bash sleep doctors specifically; the sad fact is that the majority of doctors in most medical specialities (and generalists, too) are not out of the box thinkers and they will not be up on things that are not already widely known and accepted in medicine.

User avatar
chunkyfrog
Posts: 32528
Joined: Mon Jul 12, 2010 5:10 pm
Location: in a nice, moist, Nebraska bog

Re: Non-Vented Masks

Post by chunkyfrog » Mon Oct 05, 2015 6:00 am

Q: What do you call the guy who graduated medical school at the bottom of the class?
A: "Doctor."

_________________
Machine: AirSense™ 10 AutoSet™ For Her CPAP Machine with HumidAir™ Heated Humidifier
Mask: AirFit™ P10 For Her Nasal Pillow CPAP Mask with Headgear
Additional Comments: second identical machine --sticking with a good thing.
Laughter--the best medicine--up until your giggling wakes your spouse.
"Honey, how can you be having fun without me?"

Zoopshine
Posts: 31
Joined: Mon Oct 05, 2015 8:21 am
Location: BFE

Re: Non-Vented Masks

Post by Zoopshine » Mon Oct 05, 2015 9:11 am

The masks linked appear to be for non-intubated vent patients, NOT CPAP/BiPAP patients. In the hospital setting, these masks are used when traditional intubation is either impracticable or impossible, and they are used on people who are unconscious or sedated. They are absolutely not for home use.

Just because something is "easily available" does NOT mean it is safe! Please speak with your doctor or RT prior to doing something like taping vent holes. This could absolutely kill you.

_________________
MachineMask

User avatar
Goofproof
Posts: 16087
Joined: Mon Dec 05, 2005 3:16 pm
Location: Central Indiana, USA

Re: Non-Vented Masks

Post by Goofproof » Mon Oct 05, 2015 11:39 am

archangle wrote: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?
What's the mask for, run out of garbage bags? Jim
Use data to optimize your xPAP treatment!

"The art of medicine consists in amusing the patient while nature cures the disease." Voltaire

KeepSmiling
Posts: 61
Joined: Mon Sep 28, 2015 2:32 pm

Re: Non-Vented Masks

Post by KeepSmiling » Mon Oct 05, 2015 5:26 pm

stcrim wrote: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/
stcrim,

The mask you linked to is not a Sleep Apnea Mask according to the site, it is listed under Respiratory Mask. There is a mask for sleep apnea with the same name. It has vents.

I think using a non vented mask is so dangerous and should not be attempted.

User avatar
Ford Guy
Posts: 56
Joined: Fri Dec 21, 2012 9:31 pm

Re: Non-Vented Masks

Post by Ford Guy » Mon Oct 05, 2015 5:33 pm

stcrim wrote: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.
This is what it says in this web site....
• Designed for noninvasive ventilation therapy in the hospital environment
S8 Autoset II is back up

User avatar
LSAT
Posts: 12761
Joined: Sun Nov 16, 2008 10:11 am
Location: SE Wisconsin

Re: Non-Vented Masks

Post by LSAT » Mon Oct 05, 2015 5:38 pm

We haven't heard from the original OP since early Sept. ...Maybe he tried the mask.

_________________
Machine: ResMed AirSense™ 10 AutoSet™ CPAP Machine with HumidAir™ Heated Humidifier
Mask: Fisher & Paykel Vitera Full Face Mask with Headgear (S, M, or L Cushion)
Additional Comments: Back up is S9 Autoset...... Buckwheat hull pillow

wrstlingyoda

Re: Non-Vented Masks

Post by wrstlingyoda » Mon Aug 21, 2017 5:46 am

#1. Work with a doctor who is certified by the American Board of Sleep Medicine. I have worked with mine for over 2 years and conducted 4 Sleep studies before confirming CO2 level issues that could be resolved with a non-vented mask. However, ...
#2. You do NOT use a non-vented mask by itself. The vent is moved from the mask to the hose, approximately 18" down the hose for me. This varies per person and yes, non-vented mask have been found to be dangerous; even life threatening...so, See #1 above and community often with your doctor.

EJ

Re: Non-Vented Masks

Post by EJ » Mon Aug 21, 2017 5:52 am

#1. Work with a doctor who is certified by the American Board of Sleep Medicine. I have worked with mine for over 2 years and conducted 4 Sleep studies before confirming CO2 level issues that could be resolved with a non-vented mask. However, ...
#2. You do NOT use a non-vented mask by itself. The vent is moved from the mask to the hose, approximately 18" down the hose for me. This varies per person and yes, non-vented mask have been found to be dangerous; even life threatening. This is used in combination with an ASV CPAP machine, which has many settings my doctor has adjusted over the years to dial me into the the proper and safe levels. So, See #1 above and communicate often with your doctor.

User avatar
LSAT
Posts: 12761
Joined: Sun Nov 16, 2008 10:11 am
Location: SE Wisconsin

Re: Non-Vented Masks

Post by LSAT » Mon Aug 21, 2017 10:56 am

WOW...6 straight posts on the same subject in 14 minutes....Most referring to a poster from 2 years ago.

_________________
Machine: ResMed AirSense™ 10 AutoSet™ CPAP Machine with HumidAir™ Heated Humidifier
Mask: Fisher & Paykel Vitera Full Face Mask with Headgear (S, M, or L Cushion)
Additional Comments: Back up is S9 Autoset...... Buckwheat hull pillow

joeack1
Posts: 6
Joined: Tue Jan 07, 2020 12:56 pm

Re: Non-Vented Masks

Post by joeack1 » Tue Aug 02, 2022 2:58 pm

I am currently being set up for this by my neurologist due to frequent periodic breathing episodes overnight. Its not a set up that I am doing on my own, but I am going to the respiratory co. on Thursday who will set this up for me. I would be very concerned if someone were to try and set this up on their own.

User avatar
Dog Slobber
Posts: 3338
Joined: Thu Feb 15, 2018 2:05 pm
Location: Ontario, Canada

Re: Non-Vented Masks

Post by Dog Slobber » Tue Aug 02, 2022 3:02 pm

Zombie Alert, 5 year bump.

Janknitz
Posts: 8014
Joined: Sat Mar 20, 2010 1:05 pm

Re: Non-Vented Masks

Post by Janknitz » Thu Aug 04, 2022 5:53 pm

Some zombie threads should be "disappeared" not just in the deep freeze. This is one of them!
What you need to know before you meet your DME http://tinyurl.com/2arffqx
Taming the Mirage Quattro http://tinyurl.com/2ft3lh8
Swift FX Fitting Guide http://tinyurl.com/22ur9ts
Don't Pay that Upcharge! http://tinyurl.com/2ck48rm