Dr. Shemie is a pediatric critical care physician and director of the Extracorporeal Life Support program at the Montreal Children’s Hospital, McGill University; the Bertram Loeb Chair in Organ Donation Research at the University of Ottawa; and medical director of tissue and organ donation for the Canadian Blood Services.

The circulatory standard is full of flaws.

Cardiac mechanical asystole (or absent arterial pulse) lasting anywhere from 75 seconds to 5 minutes is the U.S. circulatory standard of declaring death in donation after cardiac death (JAMA 2009;301:1902-8). At that point, mechanical ventilation and hemodynamic support are both discontinued in the operating room, and surgical procurement begins after an absent arterial pulse or mechanical contraction of the heart.

However, the current circulatory standard of death used for organ donation has scientific flaws.

First, it is based on expert opinion of a zero chance of spontaneous recovery of heart and brain functions (autoresuscitation) after 65 seconds of mechanical asystole. Scientific evidence is based on observations inferred from published case series (1912 and 1970) and one retrospective study of 12 patients in non-heart-beating donation (Crit. Care Med. 2000;28:1709-12; Philos. Ethics Humanit. Med. 2007;2:28). The sample size needed to rule out any autoresuscitation after 65 seconds in fewer than 1 in 1,000 donors is more than 10,000 patients.

Second, procured hearts have normal native mechanical and electrical functions after transplantation (N. Engl. J. Med. 2008;359:709-14; Eur. J. Cardiothorac. Surg. 2010;37:74-9), demonstrating that mechanical asystole is reversible and does not constitute an acceptable standard for irreversibility. For example, when artificial circulation is restarted with cardiopulmonary bypass for preserving organs (ASAIO J. 2006;52:119-22), donors with normal brains before mechanical asystole can recover neurologic functions.

Third, the extent of recovery of integrated brain functions during surgical procurement is unknown. A preliminary report of EEG recordings during the dying process indicate sharp increases in brain electric activities in pulseless patients (J. Palliat. Med. 2009;12:1095-100).

No neurophysiologic monitoring studies of donor brains have been done to exclude residual and clinically relevant pain or awareness during surgical procurement. Neither are there any histo­pathologic examinations of brains from DCD donors that validate the claim that 2-5 minutes of mechanical asystole will inevitably result in complete destruction or necrosis of the whole brain and irreversible cessation of neurologic functions (Crit. Care Med. 2010;38:963-70; J. Clin. Ethics 2006;17:122-32).

Transplantation advocates reinterpret the Uniform Determination of Death Act of 1981 to mean that determination of death can also be based on intent and action not to resuscitate. Procuring transplantable organs then becomes an active intervention of ending a human life, bringing up the ethical and legal questions of whether this approach requires sanctioning utilitarian homicide.