I hope that your Mom is better! :-)
I am aware of the ICU impairment thing, I wonder if it has to do sometimes with sleep impairment being a contributing factor. (?????)
The post op depression can be a different or complicating issue.
Geez, do I need to just go write a medical book? Sorry for being so boring....
This was back in the early 90's. Mom's been gone since '01. (But I still talk to her...she just doesn't answer.)