Unfortunately, even amongst the irreligious, religious fervor comes out when confronting death. There is an obligation to provide an organ, providing there is no risk to the donor. Just as one has no right to refuse life-saving therapy, one has no right to withhold vital tissue, if life is at stake. The future might involve the financially well off, but physically sick, buying organs from the needy who are physically well. Cardio-pulmonary stasis must prevail long enough for the brain to die.
Brain is very sensitive to anoxia - structural changes occur within seconds.
The Talmud confirms that decapitation is the same as death, even if movement continues, and brain stem death constitutes physiologic decapitation. By setting the respirator to detect respiratory effort, it can be determined whether the brain stem is functioning without requiring disconnection. No mistake has been made using these techniques - 30,000 cases in Sweden were accurately determined to have brain stem death with no exception. In those determined to have died, heart invariably stopped within 5 days. Man is not permitted to cause needless pain to animals, but man is given dominion over them.