Too much CO2

[DCTom]

Is it possible to re-breath CO2 and get too much of it, on CPAP? I finally gave up on CPAP because it made me feel so terrible. I tried all sorts of masks, etc., and APAP, everything you can imagine. I had no trouble falling asleep and it did not bother me wearing a mask. But wow did it make me feel bad. I feel the trouble is on my exhale. I don't think I exhale very good and maybe I rebreath my CO2. I have woken up a few times feeling somewhat like I was breathing real short and fast. I have a low pressure of 6 to 8. Does anyone have any ideas?

[Ric]

Is it possible to re-breath CO2 and get too much of it, on CPAP?

Yes, certainly. CO2 is a problem, and I would guess that everyone re-breathes some of it. Since (almost by definition) one must exceed the CPAP pressure in order to exhale, you will be blowing some of that back up the tube. Too low a pressure and you will do a really GOOD job of blowing it back up the tube. And of course re-breathing some of that.

(It's unfortunate there are no one-way valves on the CPAP masks. Or at least I haven't seen any that can prevent air going backwards up the tube. I have put some thought to it, seems like quite an engineering challenge.)

When I started CPAP/APAP the DME set the lower pressure at 4. Not only did I have a panicky feeling that I wasn't getting enough air, I also had the panicky feeling I was suffocating from my own CO2. Next night I upped the pressure to 6, and got better ventilation. Also the extra pressure did a better job of dissipating the CO2 out the exhaust port the way it was designed. I am inclined to experiment with 7 to see if that will do an even better job of getting rid of CO2 and increasing tidal volume (ventilation).

The exact pressure that works for you will depend on several factors, including the amount of air that you breathe, the pressure, humidity, tempo, whether you have C-flex or other exhalation relief built into the machine, and probably a million other things. I am beginning to think that as one uses the CPAP/APAP consistently, one probably develops stronger breathing muscles (diaphragm, intercostals, etc.) and can actually push harder and breathe stronger against the machine. And thus blow more CO2 back up the hose. I'm thinking of bumping the pressure up a notch.

My advice is, mess with the pressure, see what "feels right". It's not as dumb as it sounds. The human body is marvelously complex and knows what it needs and has a way of telling us.

(My body is telling me I need some chocolate-chip cookies.)

[george49]

Have you tried a auto bipap with biflex. even at low pressures you should be able to breath out with ease. as for the breathing fast there should be a setting in between you inhale an exhale on the auto i would say it has a low of 3 and high of 8 set it to six if you need to

[Jere]

Sometimes it as easy as keeping pillows and covers from the exhaust vents. One of the reasons I switched away from the Swift, as the exhaust can easily be partially blocked.

[2SleepDeprived]

Is it possible to re-breath CO2 and get too much of it, on CPAP?

I am beginning to think that as one uses the CPAP/APAP consistently, one probably develops stronger breathing muscles (diaphragm, intercostals, etc.) and can actually push harder and breathe stronger against the machine.

I had the occasion to view a film of a chest xray taken before and after application of CPAP. The "before" picture showed poorly inflated lungs that appeared cloudy. The "after" picture showed fully inflated lungs that were remarkably clear. So I would be inclined to agree with your deduction that the muscles would get stronger over time on CPAP (like a workout!)

[Guest]

Is it possible to re-breath CO2 and get too much of it, on CPAP?

I am beginning to think that as one uses the CPAP/APAP consistently, one probably develops stronger breathing muscles (diaphragm, intercostals, etc.) and can actually push harder and breathe stronger against the machine.

I had the occasion to view a film of a chest xray taken before and after application of CPAP. The "before" picture showed poorly inflated lungs that appeared cloudy. The "after" picture showed fully inflated lungs that were remarkably clear. So I would be inclined to agree with your deduction that the muscles would get stronger over time on CPAP (like a workout!)

[Guest]

Is it possible to re-breath CO2 and get too much of it, on CPAP?

I am beginning to think that as one uses the CPAP/APAP consistently, one probably develops stronger breathing muscles (diaphragm, intercostals, etc.) and can actually push harder and breathe stronger against the machine.

I had the occasion to view a film of a chest xray taken before and after application of CPAP. The "before" picture showed poorly inflated lungs that appeared cloudy. The "after" picture showed fully inflated lungs that were remarkably clear. So I would be inclined to agree with your deduction that the muscles would get stronger over time on CPAP (like a workout!)