Many patients diagnosed as brain dead have intact neurohumoral control of
hypothalamic-pituitary function, demonstrate normal hypothalamic mediated thermoregulatory control, and have intact autonomic function: they do not have hemodynamic collapse, they have physical findings such as bowel sounds, and are reported to have autonomic reflexes (tachycardia and hypertension) at the
time of organ retrieval.
The current clinical criteria for brain death are not consistent with the stated objective of the outcome "to identify the permanent cessation of entire brain function". Nor are the clinical criteria for brain death either universally understood, and/or correctly applied, and at least in one report, two cases were presented where the criteria were deliberately misrepresented in an attempt to retrieve an organ for transplantation.
Some physicians actively euthanize comatose patients for their transplantable organs, an ongoing practice that is particularly disturbing in light of a British study that indicated that up to 41 percent of seemingly 'permanently comatose' patients had been "misdiagnosed" and that some were actually awake and aware.