Cognitive function loss after heart valve replaced

My mother is 68 years old, and one month ago underwent an aortic valve replacement (bovine). Surgery was successful, but she has underlying medical issues related to rheumatoid arthritis and suspected rheumatoid lung. She came off the ventilator unsuccessfully three times before a tracheostomy was done 8 days ago. She is now being transferred to a ventilator facility, where they are trying to wean her from the ventilator. My question revolves around her mental status. Prior to the surgery, my mother was a mentally healthy, fairly physically active woman. She is extremely intelligent, and self-employed as a recruiter for software engineers. Now, she is exhibiting signs of loss of some cognitive function and confusion. She knows who she is, where she is, why she is there, but the changes are subtle; for another woman her age, these same symptoms might not be recognizable. She was completely sedated for 12 days, with the sedation only completely lifted 7 days ago. She was re-sedated two days ago for placement of a peg-feeding tube. Since then, she has had only .25mg Xanax.
Are these symptoms expected? Will they self-resolve? Is it possible (and with what likelihood) will these changes be permanent?


This discussion is related to RE: MEMORY LOSS AFTER OPEN HEART SURGERY.