macd
Active member
It is amazing the human race has survived this long as the air we exhale has 4% CO2. How artificial resuscitation works must be a miracle.
As said, the danger threshold s more like 7%. Far from being a sudden process, CO2 poisoning at the levels likely to be found in nature is actually a slow decent though various levels of functional impairment. Critically for mouth-to-mouth resuscitation, the body responds to elevated levels of CO2 with a heightened breathing response, which is, of course, rather helpful. (The rising urge to breathe when you hold your breath is not due to a shortage of oxygen, as you might expect, but to increased levels of CO2. )