Catholic Health Care Advocates Papers
A Medical Defense of Brain Death
Francis L. Delmonico, M.D. and Joseph E. Murray, M.D.
Recently, a story was widely circulated in the media that revealed the birth of a child who was conceived by sperm removed from the father, thirty hours after his death. Aside from the ethical issues related to the recovery of the sperm from the father, this case presents a question that has profound medical and social implications: when is a person dead?
Traditionally, a person can be declared dead when his or her heart permanently stops beating and he or she can no longer breathe spontaneously. But those classical signs of life are no longer the only accepted criteria for determining human death. The year 1998 marked the thirtieth anniversary of a definition of brain death that was introduced by the Ad Hoc Committee of the Harvard Medical School. This formulation was the impetus for the development of a death statute throughout the United States in 1981, the Uniform Determination of Death Act (UDDA).
The UDDA established that death could be pronounced in the event of either:1) irreversible cessation of circulatory and respiratory function; or 2) irreversible cessation of all functions of the entire brain, including the brain stem. By endorsing a definition of death that diagnostically evaluates the function of the brain, the UDDA emphasized the reality of death, independent of (mechanically supported) circulatory and respiratory function. The UDDA clearly affirmed that brain death means the death of a human person.
A Unified Definition
Although the two components of the UDDA (death by absence of heartbeat and death by loss of brain function) are mechanistically distinct, there is a unifying principle that provides a single concept of human death. The irreversible cessation of circulatory and respiratory function inevitably leads to an irreversible cessation of all functions of the brain. Thus, all human death constitutes an irreversible loss of brain function.
Dr. William H. Sweet originally espoused this principle in his editorial remarks accompanying a comprehensive report on brain death. Dr. Sweet noted: “It is clear that a person is not dead unless his brain is dead. The time-honored criteria of stoppage of the heartbeat and circulation are indicative of death only when they persist long enough for the brain to die” (Sweet, W. “Brain Death,” N.Engl.J.Med. 299 [1981] 410–412). Thus, the irreversible cessation of circulatory and respiratory function (as stipulated by the UDDA) can also provide a readily identifiable sign that brain function has been permanently lost, rendering the person dead.
Since the promulgation of the UDDA, society has gained a worldwide understanding that the determination of brain death is the equivalent of death. The concept of brain death does not simply imply an inability to recover from devastating neurological catastrophe. There are some patients who are unable to recover from such an injury, but they are not necessarily dead. However, the importance of the UDDA was to attest that brain death is a real manifestation of death. With the determination of brain death, all mechanical support could be ethically and legally withdrawn, independent of any consideration of organ donation, because in light of medical science, the patient is indeed dead.
Consequently, the American Academy of Neurology’s (AAN) definition of brain death is “an irreversible loss of the clinical function of the brain, including the brain stem.” The AAN criteria of brain death necessitate an evaluation of both cerebral and brain-stem function. The irreversible loss of cerebral function is fundamental; but in addition, the conceptual importance of the irreversible loss of brain stem function is to assure that an individual capable of breathing spontaneously is not declared dead.
Controversy regarding the concept of brain death is troubling for a society that should have agreement on determining death. The UDDA is unequivocal by definition; but there is substantial discord as to the nature of the clinical condition that would constitute death. The spectrum of debate extends from those who reject outright that brain death is death to those who would expand the interpretation of brain death to include patients in a persistent vegetative state.
A concept of brain death that merely identifies an irreversible loss of consciousness with death has not been widely accepted by physicians because most consider it counterintuitive to pronounce the death of an individual who can spontaneously breathe. We concur with the general societal disapproval of considering either a patient with persistent vegetative state or an anencephalic infant with some functioning brain stem as dead, because the incapacity to breathe is not a component of either clinical condition.
The Primacy of the Brain
Those who dispute the concept that brain death means the death of a person reject the premise that the ultimate measure of human life resides in the function of the brain. Their concept of life is based upon the persistence of blood circulation and not brain function. Because the integrative functions of the body can be maintained by blood circulation that is independent of brain function (for example, urine and bile can be produced in a brain dead person), Alan Shewmon, M.D., has suggested that brain death “is really not death after all but rather a state of deep and irreversible unconsciousness in a critically lesioned but still live patient” (Shewmon, A. “Recovery from Brain Death: A Neurologist’s Apologia,” Linacre Quarterly 64 [1997] 30–96).
We disagree. Our support for the primacy of a brain function concept of death is given from within a philosophical and theological perspective. The instrument of consciousness, thought, and free will is the human brain. The loss of these attributes characterizes human death as different from the death of any other form of life. If the criteria of brain death are present, it seems reasonable to conclude that a human body that cannot regain consciousness and cannot take a breath spontaneously is dead. Otherwise, such a hopeless clinical condition would obligate the physician either to maintain useless care indefinitely or to withdraw care from a live patient.
Some physicians have challenged any concept of brain death that allows for the persistence of even minimal functionality in any part of the brain. For example, the cessation of hypothalamic-pituitary function leads to loss of circulating arginine vasopressin and its clinical correlate, diabetes insipidus. Since not all patients pronounced brain dead are observed to have diabetes insipidus, the accuracy of a brain death diagnosis which does not establish the irreversible cessation of every function of the brain has been questioned.
We would respond by observing that nests of viable cells within the brain at the time of death do not negate the concept of brain death as death. An analogy in the context of cardiac death can be given to those who only accept the irreversible absence of blood circulation as death. Not every last tissue cell must be non-viable for a declaration of death by the irreversible cessation of circulatory and respiratory function. Otherwise, how could the birth of a child have occurred, who was conceived by sperm recovered from the father thirty hours after his death?
Legal Considerations
Under the law, death must be pronounced at a precise time. However, it is now clear that organs and tissues can remain viable for an extended period after death is declared. Organs and tissues can be recovered and transplanted successfully following death, whether pronounced by brain death or by the absence of heartbeat and breathing.
The central component of human life that distinguishes us from any other living creature is the function of the human brain. Three decades after the irreversible loss of brain function was established as death, brain death remains validated by current medical and legal authority as the death of a human person. Because all human death follows an irreversible loss of brain function, the concept of brain death as death should be preserved.
Francis L. Delmonico, M.D. Harvard Medical School Boston, Massachusetts Joseph E. Murray, M.D. Harvard Medical School Boston, Massachusetts From the:
The National Catholic Bioethics Centern 159 Washington St., Boston MA 02135 Phone: 617-787-1900 Fax : 617-787-4900
