My gentleman friend is 87, and was a sweet, loving, affectionate, kind, helpful, and mentally sharp man. Five days ago he underwent open heart surgery (which he wanted) to have an aortic valve replaced, and a double bypass. Ever since he woke up, he has been a different person. He is nasty, mean, uncooperative, and demanding. He gives the nurses a constant bad time by taking off his clothing and getting out of bed (even when still attached by tubing to a multitude of machines). He demanded pizza for breakfast, and Coke to drink. This is so strange because he NEVER drinks Coke (he has always insisted it is bad for the brain.) He took his blood pressure cuff off, rolled it up, twisted it, then stuffed it into a pillow! When asked why he did that, he replied, "Why not?!" When we who love him visit him, he tells us to leave him alone. Yesterday he shook his index finger in my face, while gritting his teeth. All the family is puzzled at his weird behavior. He doesn't seem like the same person. Has anyone else had this experience? Can anyone out there explain it?