If this is a concern, have them use a local, if possible. Remember, however, that after surgery they will give her pain killers. These may make her loopy and she may sound whacky. I had an accident earlier this year and after surgery hallucinated to the amusement of my children. It was the narcotics. Eventually I got all my marbles back. I am 82.
wow wish i could give you the right answer but i cant. am so sorry i really dont know anything about the surgery and what it could do, i would ask her dr and you can always go and talk to the dr who will be givingher the Anesthesia., they can tell you . plus i know my mom has had servel surgeries and has not had a problem with it, but shes been confused so could not tell.