Ketamine is a short acting anesthesia used to induce unconsciousness for short periods of time, using simple surgeries. It would be dangerous to use yourself. It could kill you, cause brain damage, etc. I can't see any circumstances where it would be benficial to you.
I thought lots of people use it illegaly. Is there a high rate of fatality?
I really don't know the rates of fatality for illegal use of Ketamine. I do know it is a bad idea and very dangerous. People use a lot of drugs illegally; that doesn't make it a good idea.