It also takes a while for the body
to adjust
to the medications; they have
to change the medications
to wean a person off of the ventilator, from what I understand.
My Dad got confused and agitated in ICU after his heart surgery (triple bypass, aneurysm repair, and aortic valve replacement--all in one surgery.) He was trying to pull out his tubes and climb out of bed, take off his gown, etc. He knew who we/his daughters were, but did not know where he was or why he was in the hospital.