My prior impression was that nitrogen (at high concentration) would induce unconsciousness quite rapidly, and painlessly. Obviously hypoxia is part of this, bu

My prior impression was that nitrogen (at high concentration) would induce unconsciousness quite rapidly, and painlessly. Obviously hypoxia is part of this, but I'd never heard of this as being distressing in itself. Does anyone have further insight on this? (CO2 buildup, on the other hand, is inherently distressing, though the AVMA doc suggests that pigs would become unconscious in about two minutes, under proper conditions.) Thanks for the link.