CO2 washout

OSADad · Post by **OSADad** » Mon Nov 27, 2006 10:13 am

I've been reading these boards for some time now. From time to time the topic of CO2 washout comes up. Sometimes people say that too much pressure can cause CO2 problems. Other people say too little pressure can cause CO2 problems. When you visit the Sites of the CPAP makers, they never even mention this at all. Is there really a CO2 washout issue to be concerned about? Have you experienced CO2 washout problems?

oldgearhead · Post by **oldgearhead** » Mon Nov 27, 2006 10:28 am

CO2 washout is another way to say "passive exhalation port flow". Most mask have build in "holes" to allow excess CO2 to escape. As you can see this varies quite a bit from manufacturer to manufacturer. Furthermore, pressure directly affects this flow. I guess you might say, "Someone at a low pressure, may like the Hybrid, because of its very high "washout" while a person at say 13 cm/H2O may not like it at all, because of the dry cooling that they may encounter at such a high flow rate.

Chart:

http://www.internetage.com/cpapinfo/leak-rates-1.html

Sleepin · Post by **Sleepin** » Mon Nov 27, 2006 11:51 pm

CO2 is usually blown off and can also cause problems of a low C02 level that the body sees as a need thus causing frequent awakenings (usually due to central events)

Snoredog · Post by **Snoredog** » Tue Nov 28, 2006 1:03 am

Jimbo776 · Post by **Jimbo776** » Sun Jan 14, 2007 1:22 am

Just to correct SnoreDog- CO2 is not produced by dead cells in the body. It is produced by every live cell in the body. Oxygen combines with sugar (Which is a 6 carbon chain, plus oxygens and hydrogens.) During the Kreb's cycle which produces energy for our cells to use, Sugar (glucose) is broken down, and combines with oxygen to form CO2. Cells then dump the CO2 into the blood stream to be taken to the lungs and exhaled. The term for this is cellular respiration.

Briefly- I have a problem with low CO2 when using my VPAP. The symptoms I have are right on target for low CO2, hypocapnia (slurred speech, dizziness, etc.) The VPAP Adapt SV is supposed to correct this, but it does not seem to do it for me, so I need some increase in CO2, either by added CO2 from a tank, or dead space or something. Will let you know if I get myself fixed up.

Jim

blarg · Post by **blarg** » Sun Jan 14, 2007 4:02 am

Not to hijack the thread, but have you tried a Soyala Jimbo?