I had to walk away from someone I cared about when she was on life support and declared brain dead. It was an experience I’ll never forget. My father had just signed papers agreeing that his wife’s organs would be donated to those in need. I had no problem with that decision, but what was incredibly difficult was looking at Linda hooked up to a ventilator and ‘breathing’. She most definitely looked alive. How could we just walk out on her?
This article from Wired magazine provides a useful look at the issue of brain death. Is brain death other than death itself? Christian Jarrett says that, surprisingly, even some doctors aren’t clear about when a person has passed away.
http://www.wired.com/wiredscience/2014/02/brain-death/