I had mine taken out this past August, not as bad as I thought it would be. I had a good doctor which helped. Get the IV, if you just get laughing gas and the general anesthesia (sp?), it probably won't be enough. I don't remember a thing from the actual procedure, nor from much of that day.
I didn't have much pain, just keep up with the medicine. The only thing is that you are going to have a really tight jaw for about a week, and you are going to be really swollenm, (I looked like a chipmunk for about a week).
I had mine done on a Friday, and I tried to go back to work on Monday, but I wound up leaving early. But by Tuesday, I felt well enough to work the entire day.
Oh, and mine were impacted as well ...