What he wrote about delusions and nightmares in the ICU really hits close to home. When I was younger I ended up in the ICU for an accidental poisoning. Initially I went in and out of consciousness, having horrific nightmares fed by the morbid happenings around me. We had many interesting patients come through the ICU. One person was there for a suicide attempt on prescription drugs. Another person had been in a car accident. At one point we even had a prisoner who had been stock-piling drugs to kill himself on. They had him hooked up to a dialysis machine which apparently works well when the drugs aren't fat soluble? It was like a real life episode of House.
Meanwhile I wasn't mentally doing that great. When I was finally conscious I started hallucinating and hearing voices. I was hearing insults from the staff that weren't there and felt like everything was done with malicious intent. It was quite traumatic. I actually remembered these delusions for years afterwards and had trouble accepting that it wasn't real. It's only been a recent thing that I've even been able to speak about such experiences without shutting down emotionally. The work that doctors and staff do at ICUs is extremely valuable. But it's definitely not a great place for a vulnerable mind.
I feel like there is more that could be done in such a situation. e.g. where someone is profoundly hallucinating. I was over-stimulated and noise was making everything worse. If I just had of had a dark room to recover in I probably wouldn't have been traumatized. Maybe even ear plugs or a mask. But I didn't even have that. I'm also kind of surprised by the OPs story because the ICU I was in was like this closed surgical ward filled with medical staff. ICUs don't really seem like a place to have visitors. I get the feeling many people there aren't even going to be conscious. OPs dad is lucky to have had such good family support.