This is not a surgery. My husband almost had it done. He was given a med to calm him. Electricity is used by putting pads on top of the chest and sending electricity to the heart. Like paddles. It should put the heart back in rhythm. Its the last thing they do. Medication is done first. My husbands heart went back in rhythm when the Dr. got there.
I would call her doctor and tell him what is going on. She may still have the problem or has had a stroke.
Anesthesia is very hard on an elderly brain. My stepdad had a hip replacement at the age of 82. He was very confused, loopy following the surgery. He spent about six weeks in rehab and by that time the brain pretty much returned to normal. It is frightening, sometimes the decline is temporary, sometimes not.
Doc's should have told the patient of this risk before the surgery. But, don't ask dad, he probably wouldn't remember if he were warned of this side effect.
Recovering from surgery is much more complicated and takes 10 times longer for people in their 80's, plus she is probably on one or more new medications - be sure to mention the changes when she sees her doctor for follow up. Where is she staying while she recuperates, does she have enough support? Is she using a walker/rollator? A bedside commode to limit trips to the bathroom? Will she be getting rehab or physio?
I would call her doctor and tell him what is going on. She may still have the problem or has had a stroke.
Doc's should have told the patient of this risk before the surgery. But, don't ask dad, he probably wouldn't remember if he were warned of this side effect.