Post by HYDROOxygen is a biologic gas and necessary for life process to function so
the concept of oxygen being toxic at ambient pressure is intuitively
impossible-think about it.Probably your convulsive condition was caused
be an allergic response to anesthetic gas instead of what you thought
was O2 delivery.I believe 2 litres/min oxygen delivery via nasal
"tubes"
is considered high as it tends to dry the mucus membranes.Mucus is
anaerobic thus re-active w/oxygen causeing irritation and a level of
exposure to secondary conditions(infections,etc.) .Oxygen toxicity
occurs in the deep diving environment due to a high partial pressure of
oxygen in a breathing gas mix.Primarily nitrox and/or heliox blends for
commercial divers cause o2 toxicity and this information may confuse
people.comment Hydro
Well, at a relatively low pressure and 21% O2, toxicity is not a
problem. Oxygen is a biologic gas and our bodies are adapted to use it
under these standard conditions. When you're at 100% 02 and at high
flow rates for long periods of time, it is possible (but not very
likely) to have a problem. Personally, I don't think you can hit it with
the 6 lpm max from a nasal cannula...but at 15 lpm or more it may be
more of a possibility.
You bring up a good point with mixed gas diving. In nitrox courses they
teach you that the likelyhood of CNS oxygen toxicity is directly
proportional to the partial pressure of O2 and the duration of exposure.
For example: 45 min of O2 at 1.6 bar is toxic and 180 min at 1.3 bar
is toxic. Now with 100 % 02, the partial pressure of 02 is roughly the
same as breathing air at 99 ft. In diving, you're likey going to have a
problem with the getting nitrogen narcosis or running out of air before
the oxygen clock gets anywhere near toxicity....but don't forget that in
a hospital setting, you could be on the oxygen for a long time. At 100 %
O2 (1 bar or normal atmospheric pressure) it is *possible* but not very
likely to have a problem, with long term use.
Michael