My son had an automobile accident 4 weeks ago. He had 18 broken ribs, a broken collarbone in the front and in the back. His lungs were bruised and one had a contusion from on do the broken ribs. They had to put him on a ventilator on the third day after it happened. He was on that ventilator for 3 full weeks. He got pneumonia in the meantime. Now since they took him off the ventilator, his mental awareness is not the way it should be. He thinks Vin Diesel brought him to the hospital, and he has said some other "off" things. They call what he has, "an altered mental status." What is it and what caused it, and what is the prognosis for such a thing?