It depends on which hospital does it. When I had mine, the docs do 4 a week so know what they are doing! Option to either lie down or bend over a hydraulic table. Had the LA over the table then dedided to lie down. They were very quick and had my MP3 playing. Lay down for an hour post and then home.
Points to note in the evidence my wife gained (always a research scientist, even at home!):
Every hospital has a different policy
There seems to be no difference in lying down to getting up straight after. Nicer to lie down post it though.
The amount of caffeine should be moderated as it could be the cause of a headache I fell for drinking too much! Although again the statistics do not really support the use of massive amounts of caffeine, just fluids to offset the shock.
In fact, the needle used to take a blood sample just after it hurt more!