Excess Carbon dioxide in the mask?

G'day again,

Just want to say thanks to everyone who has been giving me advice and helping me become a compliant CPAP user. I know that I can be neurotic but I am doing my best to make CPAP work. I have no doctor to help answer my questions - the overbooked sleep clinic that prescribed my CPAP machine (took 6 months to get into) gave me my prescription and kicked me out the door! So I have been getting my info online. I just have a couple of questions:

I have now been able to fall asleep a bit quicker with my CPAP on - before it was taking me a couple of hours. Now I can fall asleep within about half an hour to an hour. At times with the mask on I have sometimes felt a nice relaxing high before going to sleep or feeling a bit spaced in the morning. I am worried this is a sign that I have too much carbon dioxide in my mask - I use a Quattro FX small Resmed mask. The machine appears to be working okay. Does anyone have an knowledge about carbon dioxide buildup in CPAP masks? Does it happen, can it brain damage you? I may be a little neurotic but I just want to put the fear to rest by replacing the unknown with knowledge.

The second question I have - whilst getting used to the machine I seem to be a little more tired in the evenings. For example - I started excessively yawning already at about 5pm. I am also feeling a bit zombie/brain fog/spaced out and having trouble concentrating on typing this post. I had about 5-6 hours of sleep last night with the cpap on (may of been less, may have taken longer to fall asleep than I thought??). Should this be cause for concern, could it possible be related to a carbon dioxide malfunction or is this normal for people getting used to CPAP therapy. I should point out before the CPAP I was sleeping 10-12 hours per night as of 5 days ago and not waking up choking or anything like that but definitely snoring, drooling, and sometimes changing breathing patterns according to my wife.

As you can see the doctor didn't really tell me what to expect! Thanks again for any help and advice.

Hi - if CO2 is venting out through the tiny holes at the front of the mask when your machine's on, then all you have to worry about is making sure that bedding or anything else is not blocking the vent when you're asleep. You're probably just adjusting to Cpap - not used to all that oxygen, forgetting what it's like to have had decent sleep, though hopefully you'll get a little more of it... do you get to bed very late but still set the alarm to go off early?

Not a big deal, but could you include your mask in the signature profile along with your machine?

Hi Julie,

Yeah I have a bad sleeping pattern at the moment of going to bed late and getting up early. I am having a hard time getting used to the machine - but I am getting there I suppose.

Hmm, so basically as long as the air holes aren't obstructed the Carbon Dioxide will be able to vent np.

I have updated my signature to include my mask.

Thanks for the advice..

That relaxing high you feel is likely due to deep breathing. When you mask up, do you find that you are taking deeper breaths than normal? Does your breathing feel rushed? You are finally getting to breath while you sleep, you're bound to feel different in the morning for a while.

Brenda

Matty332 wrote:Hi Julie,

Yeah I have a bad sleeping pattern at the moment of going to bed late and getting up early. I am having a hard time getting used to the machine - but I am getting there I suppose.

Hmm, so basically as long as the air holes aren't obstructed the Carbon Dioxide will be able to vent np.

I have updated my signature to include my mask.

Thanks for the advice..

Matty...You said you are using the Quattro FX, but you picture the Quattro in your profile...Which is it?

The venting - is part of the mask on some or part of the hose attachment - removes the CO2. It removes the CO2 by the "venturi-effect". The same effect a smoker uses in the car with the windows up. If you crack your window, the smoke gets pulled out of the car by the velocity of the outside wind. The same effect is used on the mask. The venting will "pull" the cO2 out of the mask. The manufacturer has figured this out a long time ago, so I wouldn't worry about it. As far as feeling better, give yourself more time. You are headed down the right path. Your body will forgive the abuse of sleep apnea, but it will not forget. As long as you are progressing, it may still take time.

Sheriff

I, too, went through this period of initial fatigue when starting out.

If you think about it, this kind of makes sense. We've been living with nearly no sleep for so long, that when you finally get some real sleep, your body begins trying to make up for lost time. For me, it took about a week before I started getting used to just 6-7 hours of true sleep. Until then, I wanted to go to bed early every night, and wanted to sleep late every AM.

Within the first few weeks, my body figured out that I wasn't going to be going back to the old "sleep" pattern, and reset itself so that a normal amount of sleep was all that was desired.

Hang in there, let your body do what it feels like it needs for a few days and see if the condition becomes self-limiting.

As for the CO2, others have already said it. If the air holes in the mask aren't being blocked, then the movement of air in the mask will flush out the CO2. Also remember that even if the air flow stops, masks are designed to allow you to get air naturally. For nasal interfaces, you can open your mouth and breathe that way. For Full Face Masks, they all have a valve that opens if the air pressure drops too low or turns off. That valve allows you to breathe room air if the machine stops flushing CO2 away.

1) To put it simply, no, it's highly unlikely you have a CO2 problem.

2) Remember, it's Carbon DI oxide (CO2), not Carbon MON oxide (CO). Lots of people confuse the two. Carbon Monoxide is the stuff in car exhaust that's really deadly. The stuff that concentrates in your mask is Carbon Dioxide.

3) What is your pressure setting?

4) Check that the holes in the vent on your mask aren't plugged.

5) I don't think the Venturi effect is particularly important in this case. When you exhale, the exhaled air goes back up the hose a bit. As air leaks out the vent, the fresh air is working its way down the hose. Shortly after you start inhaling again, you will have sucked all the stale air out of the tube and will be breathing 100% fresh air.

For instance, my tidal volume is around 440 mL or .4 liters. i.e. when I exhale, I blow out 440 mL of stale air. My total leak rate is 23 liters per minute. When I exhale my .4 liters, it's replaced by fresh air every 23/.4 times a minute. That's roughly once every second.

6) Your profile shows you have ResScan. (By the way, get SleepyHead. It's free and better in several ways.) See if you can find your TOTAL leak rate and tell us what it is.

I doubt it is carbon dioxide. Check the vents on your mask. If you feel air moving, you are fine. I get a wee dizzy sometimes because I think some of the air goes up the eustacian tubes and messes with my ears. As long as it only lasts a bit, you are fine.

Matty332 wrote:G'day again,

Just want to say thanks to everyone who has been giving me advice and helping me become a compliant CPAP user. I know that I can be neurotic but I am doing my best to make CPAP work. I have no doctor to help answer my questions - the overbooked sleep clinic that prescribed my CPAP machine (took 6 months to get into) gave me my prescription and kicked me out the door! So I have been getting my info online. I just have a couple of questions:

I have now been able to fall asleep a bit quicker with my CPAP on - before it was taking me a couple of hours. Now I can fall asleep within about half an hour to an hour. At times with the mask on I have sometimes felt a nice relaxing high before going to sleep or feeling a bit spaced in the morning. I am worried this is a sign that I have too much carbon dioxide in my mask - I use a Quattro FX small Resmed mask. The machine appears to be working okay. Does anyone have an knowledge about carbon dioxide buildup in CPAP masks? Does it happen, can it brain damage you? I may be a little neurotic but I just want to put the fear to rest by replacing the unknown with knowledge.

The second question I have - whilst getting used to the machine I seem to be a little more tired in the evenings. For example - I started excessively yawning already at about 5pm. I am also feeling a bit zombie/brain fog/spaced out and having trouble concentrating on typing this post. I had about 5-6 hours of sleep last night with the cpap on (may of been less, may have taken longer to fall asleep than I thought??). Should this be cause for concern, could it possible be related to a carbon dioxide malfunction or is this normal for people getting used to CPAP therapy. I should point out before the CPAP I was sleeping 10-12 hours per night as of 5 days ago and not waking up choking or anything like that but definitely snoring, drooling, and sometimes changing breathing patterns according to my wife.

As you can see the doctor didn't really tell me what to expect! Thanks again for any help and advice.

Thanks for all the help! I really appreciate it.

Brenda
Hmm, it actually feels nice now when I put the mask on. I think the autoset 'ramps' up the pressure though over time for comfort. I am starting to like that very low mechanical wooshing sounds coming out of the machine at different stages in the breath.

LSAT
I thought they were the same product? I will pull out the box and check the model.

Sherrif,
Thanks for that knowledge. I understand how it works alot better now.

TalonNYC
It does make sense. I have had severe OSI for a year now. I shall keep doing this - it is becoming easier. Thank you for relating your similar experience.

Archangle
I DID make that mistake and had a freakout after reading the wiki page Carbon Monoxide poisoning!! Carbon monoxide poisoning is insidious and creeping - but I discovered that carbon monoxide is not generated in the lungs! Carbon dioxide is. So I looked up carbon dioxide poisoning - you would know if you had it, I even discovered that minor carbon dioxide poisoning has a neuroprotective effect on a brain that has been exposed to Hypoxic damage! You can get hypoxic damage from OSI. I feel ALOT better knowing this!

Kairo
I see, that would explain any dizzyness then. Thanks again.

Matty332 wrote: At times with the mask on I have sometimes felt a nice relaxing high before going to sleep or feeling a bit spaced in the morning.

Matty,

Did the issue of feeling "spaced in the morning" get resolved? Do you still feel this way? Thanks very much.

Matty,

What pressure or pressure range is your machine set to? Are you monitoring (with software) the data your machine collects?

The following is from the S9 Provider manual warnings:

* At low pressures, the flow through the exhalation ports of your mask may not clear all exhaled gas
from the tubing. Some rebreathing may occur.

You mentioned you're using a Quattro mask. Some years back, some of us were experiencing symptoms similar to yours when using Quattro masks (even at higher pressures) and discussed (on the forum) the possibility that the Quattro had an insufficient vent flow to expel the CO2. I don't recall that we came to a definite conclusion, but the fact that it didn't occur with masks we regularly used made it suspicious. I've never had those symptoms with my ResMed Ultra Mirage Full Face masks.


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Hey Sylvie and Guest,

In regards to feeling spaced in the morning, it has resolved yes. I no longer feel that way when waking BUT sometimes I may feel lightheaded rarely when waking with the chance of vertigo if I turn my head too fast but I have spoken to other users on this forum and the general consensus is that because I am on constant pressure 20, ear wax is being blown deeper into my ears and the pressure sometimes plays with my ear pressure balance - especially if I have slept on my side.

I still feel euphoria when I put my CPAP on and my humidifier warms up though, I think I am the only one that I have met here that experiences that. It is nice but not harmful apparently.

Guest,

I am now on the highest pressure the machine will go on constant 20 - but since replacing my Quattro FX with a Mirage Quattro, I have had a lot less weird problems and my treatment is much more effective. I need to keep the head strap tight and the mask low on my nose to prevent it moving up and the bulk putting pressure on the inner sides of my eyes - but doing this causes a massive blister on the bridge of my nose which I am still trying to find a solution for.

I thank you for that information - when I was having those problems with feeling drugged and spaced in the morning I was using the Quattro FX mask and my CPAP was set in APAP mode on very low pressure too. Interesting..

Thanks, Matty. I'm glad you feel better. On another website ( having to do with apnea and asthma) I found a lady who described very similar symptoms. I sometimes think I have the same symptoms, but for different reasons than you (my pressure is low and I use pillows; PM me if you want the website). Just curious, have you ever thought about getting an oral appliance so you can lower your pressure? I don't know if you'd be a candidate, but it might be something to look into. I'm a big advocate to lowering high pressures whenever possible.

My most recent physical, my CO2 is elevated in my blood! This is the first time my carbon dioxide has been elevated and the first time I am using a CPAP machine: sleepMapper, Phillips Respironixs, system one. I will point out the company did not permit you to look or try sample masks, nor did the have various sizes. When I visited my MD, his partner, working in sleep apnea did have assorted masks. The small mask was much more comfortable, but I use the medium size. Unless I pull the mask down over my upper teeth, the air use to blow in my eyes. Pulled down, no air escapades the mask.

If my CO2 is elevated to abnormal levels in my blood, it must be from CPAP. Am I even safe to continue?