The patient had been in a coma for some time when one of the nurses happened to notice a distinct response on the monitor when her "private area" was touched during a sponge bath.

"Crazy as this sounds," said the nurse to the patient's husband on his next visit, "but maybe a little oral sex will do the trick and bring her out of the coma."  He's quite skeptical, but the staff assures him that they'll close the curtains for privacy and points out that they don't have much to lose.  Finally the husband agrees to give it a shot, and goes into the wife's room.

After a few minutes the woman's monitor flatlines.  No pulse...no heart rate.  Running into the room, they find the husband standing there, zipping up his fly.  "I think she choked." he said.