Brain death concept to be reviewed

“The discussion of brain death should arguably focus on the concept of the death of the person, rather than the concept of complete bodily death or absence of integrative functions.”

The diagnosis of death by neurological criteria, often called brain death, has been contentious since its conception in 1968 through a publication entitled “A Definition of Irreversible Coma. Report of the Ad Hoc Committee of the Harvard Medical School to Examine the Definition of Brain Death”. Although the concept of brain death has been gradually extended over the years — it is currently recognized in most developed countries as a concept of death from both a medical and legal point of view — its conceptualization and implementation have not been free of controversy (read Diagnostic tests for brain death: this is the time for universal uniformity).

In the aforementioned JAMA article, the then “new” concept of death (up to that point, only circulatory and respiratory criteria were considered to establish death) based its understanding on two purely utilitarian aspects. The first was the need for intensive care beds for critically ill patients with a chance of survival, which should not be occupied by patients with no reasonable prospects of recovery; and the second was the need for organs for transplantation that could be met by these “new deceased”. As early as 1968, the fact that the authors of the article did not focus on the patient’s own need to stop treatment on the basis of its futility drew attention. All of this led to the turbulent emergence of the concept of death based on neurological criteria.

Possible existence of spurious interests in the diagnosis of brain-dead patients

In a recent opinion piece published on the Bloomberg website (Read HERE), entitled “A Scary Plan to Revise the Definition of Death”, the author reflects on the possible existence of spurious interests in the diagnosis of brain-dead patients, as well as emphasizing the heterogeneity of criteria that continue to inform the declaration of death in persons with irreversible brain damage.

The article mentions how, in the first edition of the Presidential Committee’s report in the United States (US) in 1981, the Uniform Law Commission proposed a legal model for the determination of death, equating the cessation of brain functions to the cessation of circulatory or respiratory functions. This was accepted by most states in the US.

There are currently various schools of thought within the Commission who suggest that the definition established in 1981 should be revised, a proposal that has been gaining followers, but that other authors consider risky.

If such a revision were to occur, the main aspects that the author of the Bloomberg article considers ethically risky are:

1.-It would allow the diagnosis of death in people who still have activity in the hypothalamus (a region located in the brain stem);

2.-It would define clinical criteria within the legal document itself, and

3.-It would allow the apnea test (one of the essential clinical tests to confirm the absence of brain stem activity) to be performed without the prior informed consent of the patient’s family.

Avoiding confusing brain death with coma

The reluctance to consider the current legal model proposed by the Uniform Law Commission or even the future model with the possible modifications incorporated has been voiced by a group of international experts headed by Dr. Alan Shewmon, emeritus professor of pediatric neurology at UCLA. In a joint statement opposing the revision of the death criteria, Dr. Shewmon said that this revision could lead to a reduction in the requirements to establish the death of the person based on the absence of brain functions. He also raises serious objections to the current guidelines, saying that they already carry a high risk of classifying people as dead, when they are not. Shewmon himself insists that this possible error (confusing brain death with coma) could be due, among other reasons, to a drop in the cerebral blood flow, which does not necessarily mean the death of the patient. He has also claimed that some patients previously diagnosed with brain death have survived. Finally, he rejects the fact that the apnea test may be performed without the informed consent of the family, arguing the danger that this technique can pose to life.

Brain death to be reviewed. It can’t be a matter of dispute in current advances in neurology

The now-classic dispute between the Uniform Law Commission and the group of scientists, bioethicists, and legislators headed by Dr. Shewmon has recently been reignited. A few years ago, a meeting of the US President’s Council on Bioethics was held in Washington, where Shewmon presented a paper entitled Controversies in the Determination of Death”. In the document, he showed evidence that there were multiple signs of integrated activity in patients diagnosed with brain death. For him, most brain-mediated integrative functions are not somatically integrative, but the reverse. Among the integrative functions that this author describes as present in patients with brain death were:

1.- Breathing, assuming as such, cellular respiration, and understanding that the apnea that exists in the body in brain death is only a manifestation of the ventilation generated by the respiratory system, which can also be easily supplied mechanically with artificial ventilation systems;
2.- Nutrition; it is possible to maintain a completely normal nutritional status in patients with brain death, with the organism able to metabolize nutrients that are supplied to it, metabolize them, produce energy through the nutrient intake, as well as generate degradation products of cellular and organic metabolism;
3.- Homeostasis;
4.- Wound healing;
5.- Fighting of infections;
6.- Immunological reactions to foreign substances or bodies;
7.- Elimination of cell degradation products in all organs and cells of the body;
8.- Development of a febrile response to infection;
9.- Successful maintenance of pregnancy in pregnant women diagnosed with brain death;
10.- Proportional growth in children diagnosed with brain death;
11.- Sexual maturation in children diagnosed with brain death; and
12.- Generation of adequate energy balance and interaction of cellular nutrition systems, endocrine system, etc.

In recent years, not only has no middle ground been reached between the Presidential Commission and the group led by Dr. Shewmon, but this has been made worse by the Commission’s interest in making changes to the criteria for death in relation to brain death.

The difficult discussion that the world of concepts entails has obstructed this point of union between the two groups. Both probably have elements of reason, which perhaps combined may provide a better overview for devising the proper implementation of the diagnosis of death by neurological criteria not only in the US but in the rest of the world.

Diagnostic of brain death to be reviewed by clear neurological criteria

The biological objections presented by Professor Shewmon, listed above, leave no room for doubt. This entire group of biological phenomena described can be found in patients who have progressed to death by neurological criteria. Shewmon was probably right too when he tried to segregate the concept of “loss of bodily integration” that the Presidential Commission proposed as a key element of the person, since indeed, after brain death, elements persist that interrelate various bodily structures synchronously, with no need for brain involvement.

A “localist” view of brain death is inadmissible

In addition to the aforementioned, in this controversy, there is a “localist” view of brain death, mainly in the US, the possible existence of spurious interests in the diagnosis of brain-dead patients. We cannot overlook the fact that, although the Presidential Commission conferred generic norms suggesting the legislative changes that should be implemented to establish death by neurological criteria, each of the States developed different policies; the result was differences in the clinical and instrumental criteria for establishing death so that a person could be legally dead in one state, and legally alive in another. Accordingly, it seems prudent that criteria should be unified that facilitate — but without leading to utilitarianism — diagnosis of death of the person by neurological criteria.

The initially well-intentioned debate by Dr. Shewmon could probably be settled if the discussion did not focus exclusively on the conceptual definition of brain death provided by the Presidential Commission, but rather on the definition used by other schools, both medical and bioethical.

Only the use of clinical criteria can demonstrate not only the irreversibility of the situation but the absence of sufficient biological substrate for the persistence of the essential biological basis for the human person should be accepted

Bioethical statement

The use of clinical criteria, in which an exhaustive and complete examination of both the brain and the brainstem is carried out, once all the prerequisites for said examinations are fulfilled, can demonstrate not only the irreversibility of the situation, but the absence of sufficient biological substrate for the persistence of the essential biological basis for the human person. Nor does it seem right to concentrate the concept of “life of the person” on a mere homeostatic interrelationship between different parts of an individual.

The discussion of brain death should arguably focus on the concept of the death of the person, rather than the concept of complete bodily death or the absence of integrative functions. Although the distinction between a human being and a human person is still widely debated, in order to confirm the death of the person, the absence of the biological basis essential for anchoring the person in the body must be verified, and the extinguishment of all bodily biological phenomena should not necessarily be required.

José María Domínguez

Bioethics Observatory- Institute of Life Sciences

Catholic University of Valencia