My mom was an ICU nurse for a good twenty or more years. In her words, people in the ICU either just got out of surgery, or they are there to die, and the ones that just got out of surgery don't stay there long.

She also told me that after a while, you could tell when a person was dead, and their body just a piece of meat kept alive by machines. She said she wasn't sure if there really is a "soul" but whatever it was that made the difference between a human and a pile of meat was gone. She hated the families that kept the meat alive, while feeling sorry for them at the same time. She eventually burned out from so many years in the ICU and switched to a different type of nursing.