"Brain dead" has a very specific clinical meaning, and is not the same as PVS:
"Neuroscience experts continue to define brain death as irreversible cessation of all functions of the entire brain, including the brain stem. This definition remains consistent with the definition of brain death initially presented by the President’s Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research.1,13"
More info, including "Criteria for Clinical Determination of Brain Death":
http://www.aacn.org/aacn/jrnlccn.nsf/0/5ebf8de743ead0fa8825674e005a8950?OpenDocument
I think the media are making things harder by limiting coverage to simple issues and telling everyone to get a living will. More outrage and support would come if the abuse and fraud were covered well.