this must be rather unpleasant:

"We still don't have a monitor that can tell us about depth of anesthesia (and) awareness," he said, adding that controlling that is still an art.

"While you're laying there on the table," she recalled, "you are thinking, praying, cursing, plotting, pleading, trying to crawl off the gurney, trying to kick, scream, move any part of your body to let them know you're awake. In effect, you are entombed in a corpse."
http://news.yahoo.com/s/ap/20080314/ap_on_he_...ovZJhB_RBBDeY0hWa_vrVJRIF