Whetstine L, Streat S, Darwin M, Crippen D, in: Critical Care, (2005, vol. 9, pages 538-542), "Pro/con ethics debate: When is dead really dead?".
The above article is a review of the ethics of Donation After Cardiac Death (DCD), which is the emerging practice of harvesting living organs for transplant within minutes of cardiac arrest in patients for whom resuscitation is not deemed appropriate. DCD is legally identical to cryonics performed under ideal conditions, and raises similar ethical and technical issues. In part of his contribution to this article, cryonics expert Mike Darwin makes the following observation:
“The utility of the information-theoretic criterion of death to this case and this discussion is to point out that few if any patients pronounced dead by today’s physicians are in fact truly dead by any scientifically rigorous criteria. A further and even more disturbing complication is the rapidly advancing technology of organ cryopreservation . Using ice-free cryopreservation methods (vitrification), reversible long-term function of the mammalian kidney has been achieved after cooling to –135°C (Fahy GM: Vitrification as an approach to cryopreservation [abstract]. Presented at the 42nd Meeting of the Society for Cryobiology, Minneapolis, Minnesota, USA, July 24-27, 2005). Using essentially the same techniques, investigators have been able to achieve indefinite cryopreservation of the mammalian brain with intact ultrastructure and substantial preservation of metabolic and electrophysiological activity . Long-term reversible cryopreservation of the mammalian brain would, in effect, enable most of today’s terminally ill or even ‘DCD’ patients to engage in speculative medical time travel in pursuit of a cure , further complicating the issue of when death is.”
Above comments notwithstanding, Darwin concludes on pragmatic grounds that legal death should remain defined on the basis of cardiac death when resuscitation is not indicated, thus facilitating both DCD and cryonics under current law.