Lumbar Puncture under general anesthetic?

I am 13 and I have to have a lumber puncture, I have had one before and they were unsucessfull and didnt get anything, it hurt like hell and wasnt worth the pain. I was given a tablet which i went hypo on, i had a reaction. I am terrified now of having another one dure to past experiences, seeing I am young can they give you something to knock you out completely, and last time they used local anesthetic........ did NOT work :P