The anesthesia is scary - my grandpa-in-law was never the same after he had surgery. He went in totally lucid and came out of surgury totally out of it with dementia-like symptoms. It was permanent and it made him have to go into a home. He didn't even know who I was anymore. The surgery itself was routine and very uneventful but the difference in mental function pre and post op were as dramatic as night and day - and permanent.

I mentioned it to my doctor in casual conversation and she says she has seen that happen before when older people have surgery, especially those in not so great health. The article says "researchers hit on two other factors that increased the chances a patient would become dramatically confused after an operation: being older than about 70." He was about 80.