In order to ethically transplant vital organs from a consenting donor, it is necessary that the donor’s death be confirmed. This is the principle underlying the “dead donor rule,” requiring that donors of vital organs be confirmed dead before transplant. Were this rule not followed, the result would be transplantations that euthanize the donors for the sake of the recipients. Often, the ethical necessity of confirming death prior to transplanting vital organs can be in tension with the practical necessity of transplanting vital organs while they are still healthy. A person’s organs can begin decaying quickly after death, so time can be critical and timely diagnosis of death essential.

Definition of Death

In order to identify criteria for determining that a person has died, we should first consider what death is. Fortunately, our Catholic tradition gives us a clear answer to that question: Death is the separation of the soul from the body. Human beings are composed of bodies and souls, which give life to those bodies. Using the language of Aristotle, the Catholic tradition also teaches that the human soul is the form of the human body, and brings integral unity to the body. Of course, the separation of soul and body is not something we can directly observe. In order to confirm that a person has died, therefore, we must identify the effects of the separation of that person’s soul and body that we can observe.

Since the effect of a human soul informing a human body is to give it integral unity, an indication that the soul has separated from the body is the loss of the body’s integral unity. When a person dies, the parts of her body are no longer integrated as a single whole; this loss of integral unity is manifested in the various stages of the body’s decay. In order to determine that a person has died before the onset of bodily decay, two criteria have been identified.

Criteria for Determining Death

As we have seen in a previous reflection, the two criteria for determining a person’s death, according to medical experts and the laws of many countries including the U.S.A., are the cardiopulmonary criteria and the neurological criteria. The cardiopulmonary criterion for determining death is the irreversible cessation of respiration and circulation of blood. The neurological criterion is the irreversible cessation of all brain function. If either of these criteria have been met, the experts and laws maintain, we can be sure that the person in question has died.

These two criteria, in addition to having the support of medical and legal authorities, seem sufficient to identify human death as understood in the Catholic tradition. The cardiopulmonary criterion, irreversible loss of breathing and pulse, clearly demonstrates the cessation of bodily integrity, since the body cannot maintain function without circulation of oxygen. The neurological criterion is more controversial. Some experts question whether a living brain is necessary for the integral unity of the body. However, Pope Saint John Paul II has stated that ascertaining death by neurological criteria, “namely, the complete and irreversible cessation of all brain activity, if rigorously applied, does not seem to conflict with the essential elements of a sound anthropology” (August 2000 Address to the 18th International Congress of the Transplantation Society). The sound anthropology he refers to includes the understanding of human beings as composed of soul and body and human death as their separation.

Diagnosing Death

In order to determine that a donor of vital organs has died prior to transplantation, it is necessary to take adequate clinical measures to determine that the criteria have been met in each case. So if a person’s death is diagnosed according to the cardiopulmonary criterion, it is necessary to clinically determine that respiration and circulation have irreversibly ceased. Determining that the cessation of respiration and circulation is irreversible is not the same as deciding (through, for example, an order not to resuscitate) that the cessation of respiration and circulation will not be reversed.

Demonstrating that the neurological criterion has been met is not necessarily more difficult. It is however, more problematic, due to the fact that frequently used tests are insufficient. Many clinical tests demonstrate partial loss of brain function, but not complete loss. There seems to be a frequent disconnect between the legal standard – irreversible cessation of all brain activity – and the means used to diagnose death, which demonstrate only partial loss of brain function. We may, as a consequence, have reason to be concerned that the “rigorous application” of the neurological criterion, which Saint John Paul II has called for, is not standard practice. In which case, we would have little assurance that “dead donor rule” is consistently being observed.