Posted by MHK on November 26, 2001 at 12:38:39:
In Reply to: Why isn't oxygen narcotic? posted by Maddiver on November 26, 2001 at 12:05:25:
If you look to the Bunsen solubility tables you'll clearly see that on a strict comparison that Oxygen is MORE narcotic then Nitrogen. .110 -v- .052.. THe Meyer-Overton rule states that the anesthetic potency of a gas is inversly related to its lipid solubility. In English that means more lipid soluble gases produce narcotic effects al lower concentrations then less soluuble gases.. So why then do we believe that N2 is worse then 02???
There are many reasons we believe N2 at depth is bad, among them is narcosis and the answer to the comparitive issue is that the prevailing theory is that 02 is metabolized whereas N2 is an inert gas.. What that means is that a diver may not feel the narcotic effects as much since the tissue oxygen partial pressure does not increase as much as a non-metabolized gas [ ie; N2]..
You'll need to read the Meyer-Overton rule, circa 1908, for a more detailed analysis, but the above is the reader's digest version of the story..
Later