conference proceedings of congress International Bioethics 1999. Bioethics and dignity in a pluralistic society
Table of contents
Determining the time of death: new evidence, new controversies
D. Alan Shewmon, MD.
Professor of Pediatric Neurology.
UCLA Medical School, Los Angeles.
- First defence of brain death and "neocortical death".
- First turning point: the withdrawal of "neocortical death".
- Second turning point: the withdrawal of the "death of the whole brain".
III. Empirical evidence for an organism as a whole at brain death
- Fallacy of necessarily imminent asystole
- Litany of integrative functions
- Somatic physiological equivalence with the high spinal cord section
V. What difference does it make?
It is a great pleasure to be back in Pamplona once again, to renew old friendships and make new ones. My sincere thanks to the organisers for this invitation.
Since my previous visit here, in 1998, there has been much discussion about the topic of this lecture. I will try to briefly summarise my conceptual pathway briefly, and then focus on some empirical considerations core topic which, in my view, have cast serious doubts on this idea of the last thirty years that the death of the brain is equivalent to the death of the human organism and of the person. In case anyone might be interested, the autobiographical component of this lecture has been published, in greater depth, in a 1997 article in Linacre Quarterly1, and the rest of the lecture is adapted from a 1998 article in Issues in Law & Medicine2, derived from a presentation at the 20th Anniversary Symposium of the Linacre Centre for Health Care Ethics in London3.
1. First defence of brain death and "neocortical death".
Seven years before my first visit here in 1998, I completed my clinical training and started my academic degree program in paediatric neurology. As a neurologist, I was frequently consulted by the I.C.U. to confirm diagnoses of "brain death". As a conscientious Catholic, with some notions of Philosophy, I was also interested in understanding why the death of the brain should be equated with the death of the patient. In more philosophical terms, I needed to understand why the destruction of only the brain made it incompatible for the body to be informed by a human soul.
It is probably fair to say that many, if not most, non-medical people (and this is well exemplified by journalists) do not really believe that brain death is death, but regard it essentially as a useful legal fiction, which they are happy with simply because there is a strong consensus among experts4. For me, a legal fiction was an insufficient reason to declare someone dead. Moreover, I was supposed to be one of those experts, and I needed to understand the instructions of the consensus and not merely its sociological reality. As the history of science has proven more than once, unanimous consensus on the part of experts does not necessarily correspond to truth.
So I undertook a careful study of the medical and ethical literature, and consulted numerous physicians, philosophers and theologians on topic. Surprisingly, I found a disturbing amount of confusion even among the experts. It is not uncommon for physicians, even those involved in transplantation, while nominally equating the notion of brain death with death, to drop slip slips of the tongue that reveal that they actually believe these patients are alive, albeit dying, and, for all intents and purposes, practically dead. Despite several decades of effort educational by medical and legal organisations, this confusion around such a fundamental notion as life and death remains entrenched among health professionals, most of whom are unaware of their own confusion about subject. They think they understand brain death, even that its equivalence to death seems "obvious"; yet when questioned Socratically, they are unable to articulate a coherent explanation. This is even the case with many neurologists, who are usually taught that brain death is legal death, but not why.
Even if we could diagnose with great accuracy that the brain is dead, if we cannot explain in a convincing way why the patient is therefore dead, to proceed to treat the patient as dead, especially in the context of organ donations, is a serious moral hazard. I believe that the following words of Pope John Paul II, from Evangelium Vitae, apply to this subject of conceptual confusion, as well as to more specific cases of diagnostic "fudge":
"We cannot remain silent in the face of other, more deceptive, but no less serious or real forms of euthanasia. These could occur when, for example, in order to increase the number of organs for transplantation availability , organs are removed without respecting the objective and appropriate criteria certifying the death of the donor"5.
If we cannot make a morally certain argument that a dead brain is equivalent to a dead patient, we have no right to remove spontaneously beating hearts from these patients simply on the basis that the diagnosis that their brain is destroyed is medically accurate. Although these words of the Pope date from 1995, I was fully aware of the importance of this problem at the beginning of my degree program in the early 1980s, and I was already keen to resolve it for the sake of my own conscience.
I accepted as correct the distinction, emphasised by Bernat and his colleagues6 , into three levels of discussion that are often confused: first, the definition of death - an essentially philosophical question; second, the anatomical criterion that concretises this definition - a hybrid of philosophical and medical issues; and third, the clinical signs or tests that determine the actual occurrence of that anatomical criterion in each concrete case - a purely medical topic . Although Pope Pius XII left the determination of the moment of death to the skill of the medical profession7 , he was clearly referring to the second and third levels: the clinical details corresponding to a correct fundamental concept of death. In no way could he have meant that it was skill of the medical profession to decide that the philosophical concept of death was correct according to the teachings of the Magisterium on the nature of human life.
So, let's start with the fundamental concept of death; after all, what good would a valid clinical criterion for an invalid concept be? After reviewing the extensive literature on brain death, the reasons offered to explain why brain death should be equated with death seemed to fall into three basic, mutually exclusive categories.
* The first sociological era: the loss of recognised membership of human society: an arbitrary, culturally relative social construct, which is now, in developed countries, brain-based.
* The second psychological era: the loss of essential human properties or personality, independent of the vital state of the body. This is species-specific and applies to many cognitively impaired human beings, apart from brain death. This reduces personality to consciousness, reduced in turn by most (though not all) proponents to a material product or epiphenomenon of the brain's electrochemical activity.
* The third biological era: the loss of the integrative unity of the body. This is not species-specific and corresponds to the ordinary understanding of the word "death".
A variation of this third explanation might be called psychosomatic, according to which death requires both the irreversible loss of consciousness and the cessation of the body as a whole. Thus, as long as a person's consciousness is maintained by the functioning of the brain, that person is alive even if the rest of the body is destroyed (a hypothetical possibility not contemplated by the third reason). Conversely (and in contrast to the second reductionist explanation), a human person remains alive, even if unconscious - even permanently and irreversibly unconscious - as long as his or her body is kept alive as a biological organism.
It became clear to me in the early 1980s that both the sociological and culturally relative and the reductionist explanation of personality, the psychological explanation, were incompatible with the Judeo-Christian view of human life, and particularly incompatible with the Aristotelian-Thomistic view of the soul as a substantial form or as a vital principle of any living being. In human beings the soul has a spiritual dimension, so that the principle of personality is also the principle of the substantial unity of the body. This Aristotelian-Thomistic view contrasts sharply with Platonic-Cartesian dualism, which equates the soul with the conscious mind, substantially distinct from and inexplicably linked to the body, which in turn is regarded essentially (at least by Descartes) as a machine, merely composed of an organic material rather than wood and metal.
The notion of the soul as forma corporis was even defined as a Catholic dogma in 1312 at the Council of Vienna8 and has been ratified in more recent pronouncements of the Magisterium. It was also underlined by Pope John Paul II in his speech for the Pontifical Academy of Sciences in 1989:
"(Death) occurs when the spiritual principle that guarantees the unity of the individual can no longer exercise its functions in and on the organism, whose elements, left on their own, disintegrate"9.
The same concept has been expressed in the secular sphere, although without the term "soul". For example:
"We define death as the permanent cessation of the functioning of the organism as a whole.... (i.e.) of the innate and spontaneous activities carried out by the integration of all or most of its subsystems... and of the at least limited response to the environment"10.
I accepted this "orthodox" view of the nature of human life and realised that it entailed two relevant immediate consequences with respect to topic of brain death (actually, they are two ways of saying the same thing):
* first, if there is a living human body, there is ipso facto a living human person; and
* Second, unconsciousness per se, even that which is irreversible, is ontologically a cognitive incapacity, not death.
In the early 1980s, it seemed quite clear to me that the destruction of the brain was the anatomical criterion for such a concept of death, because the brain was the critical organ for both consciousness and the integrative unity of the body; therefore, brain destruction would leave no subject to be informed by the soul, thereby bringing about the substantial change that we call death.
What seemed to me at the time to be the most convincing argument in favour of this conclusion was a thought experiment that involved removing the brain from the body and preserving both the brain and the brainless body through medical technology. I thought that, since the person remains conscious through the brain, the body (in the technical sense of subject informed by the person's soul) in this hypothetical scenario should be the brain. The brainless body is no longer the body of a person and, not being informed by the soul, must not really be a body, strictly speaking. Rather, there must have been a substantial shift either to a disunited set of organs, or to a lower level non-human organism.
Since in principle the cerebral hemispheres can be maintained conscious by electrical stimulation of the activating reticular system at its junction with the brainstem11 , the thought experiment could hypothetically be extended to the maintenance of stimulated cerebral hemispheres on the one hand, and a body with a brainstem but no hemispheres on the other. Thus, it seemed to me that the most compelling reason that whole-brain death equals death logically implied that what is called "neocortical death" (a form of persistent vegetative state) must also be death, even though the body left behind was clearly a living organism, biologically speaking: the substantial change was not to a multiplicity of cells, but to a lower-level organism (with a subhuman soul). Thus, I arrived at the same anatomical criterion defended by the second explanation, though by means of a very different and non-reductionist logical path, which seemed to me perfectly compatible with the hylemorphic notion of the human soul conceived as a substantial form of the body.
With the test of that thought experiment that brain death was death, I conducted my entrance in the literature on brain death in 1985, in the philosophical journal The Thomist12. Considering the neocortical extension, I tried to emphasise the distinction between metaphysical conclusions on the one hand and ethical public policy proposals on the other. Although it seemed to me that the whole-brain explanation was logically extensible to "neocortical death", (thus sharing the conclusion, but not the explanation of the personality reductionists), I was far from advocating that we start removing organs from patients in a persistent vegetative state. Even if they were objectively truly dead, very few people would be able to understand it, and if the "neocortical death" specialists were willing to act on their convictions, everyone else would be seriously shocked, thinking that a crass utilitarian crime was being performed and condoned, and that state of public events would be far worse than the relatively few years of extended and unlived life of the relatively few recipients of those organs. But he also recognised that there was no certain clinical means of diagnosing "neocortical death", as there was for "total brain death".
The reaction to article in The Thomist was a mixture of praise and criticism, even from orthodox Catholic circles. I wanted to be on the right track, so I took advantage of a trip to Europe in 1988 to spend a few days here at the University of Navarra.
Given that organ transplants had been performed here in cases of brain-dead donors, I figured that if there was an institution that had a convincing and coherent explanation, compatible with Catholic anthropology, for why donors with a beating heart were dead, it would be the University of Navarra. Those three days were wonderful, but I must admit that I was surprised to discover that there was no unified framework conceptual work . Rather, it seemed that doctors and philosophers/ethicists were working in totally different, parallel worlds, with relatively little intercommunication. The more expert theologian at subject maintained that donors with a beating heart who were brain dead were not dead, although he maintained the lawfulness of harvesting organs from them. The doctors, on the other hand, simply took it for granted that brain death was death, but presented no convincing explanation for the equivalence. There seemed to be an unspoken assumption that the skill to diagnose death belonged exclusively to physicians, not to philosophers or theologians; and if those in the medical profession were of agreement that the death of the brain is the death of the patient, then so be it. (I do not know what interdisciplinary collaborations have taken place since then, though I presume that a more unified institutional approach to the problem has been taken.)
2. First turning point: the withdrawal of "neocortical death". 
A little later, in 1988, a significant event occurred, which caused me to begin to rethink topic completely. I witnessed a couple of cases of children who were born without cerebral hemispheres and yet with an intact brain stem, a condition called hydroanencephaly. All the relevant literature stated unequivocally that such children necessarily remain in a vegetative state indefinitely. However, these two children were quite conscious, at least in the sense of their adaptive interaction behaviour with the environment. They distinguished familiar from unfamiliar people and music, and showed appropriate emotional responses to music. One of them even had functional vision without a visual cortex and could crawl on his back, pushing with his legs, visually avoiding any collision with objects. I was so amazed by the neuropsychological iconoclasm that, with the parents' permission, I made a special visit to their home to examine the children and analyse their medical histories, and recorded their conscious behaviours on video13. Here is one of them examining an object and even showing fascination with his own mirror image. Subsequently, I came across several more such cases and recently published a article on the phenomenon and its implications14.
The most important implication for me at the time was that the empirical basis for extrapolating the thought experiment to "neocortical death" had indeed been demolished. Thus, in 1989 at the 2nd group of work of the Pontifical Academy of Sciences for the determination of the moment of death, I retracted the neocortical extension proposal in my previous article , suggesting instead that the minimum distribution of brain destruction necessary and sufficient to constitute death included at least the cortex, the diencephalon and the reticular training of a brainstem15.
3. Second turning point: the withdrawal of the "death of the whole brain".
It was in 1992 that the second major turning point occurred. It was induced by the discovery that, just as the cortex alone was not absolutely necessary for consciousness, the brainstem and hypothalamus were not absolutely necessary for the somatic unity of the organism as a whole (for reasons I will explain shortly). As a supporter of the teaching that the human soul is both the spiritual basis of the personality and the substantial form of the body, I regarded the non-dissociability of the "human person" and the "human organism" as a fundamental axiom, logically more secure than any conclusion from a hypothetical thought experiment. I felt forced, therefore, to abandon the notion of brain death as death.
It was only much later that I realised that the hypothetical thought experiment was actually directed at a question subtly different from the one I thought I was questioning. The thought experiment was concerned with the problem of enumeration and identity of organisms rather than that of the essence of an organism. In the context of clinical brain death, no two physically distinct entities require the same effort to resolve the question, which of these is Smith? There is only one entity in question, and if it turns out that the organism is as a whole, then it can only be Smith, an unconscious, disabled and very sick Smith, perhaps, but not yet a dead Smith. Whether a brain-dead body is a unitary organism is a question that is not covered by the thought experiment; that is something that can only be decided by examining the biological properties of particular brain-dead bodies, and seeing whether such properties are on a holistic level or are all merely on the level of organs and cells.
This is the issue on which I will focus the rest of lecture.
III. Empirical evidence for an organism as a whole at brain death
To develop what follows, let us accept as a premise that the loss of integrative somatic unity (cessation of the organism as a whole) is the appropriate concept of death and examine whether the total destruction of the brain fits this concept. If it does not, then a fortiori the destruction of part of the brain, such as the brainstem (as is held especially in Britain), will not fit either.
1. Fallacy of necessarily impending asystole
An important line of evidence cited in defence of the brain as the integrative clinical part of the body revolves around the cardiovascular instability of the brain-dead body. As Christopher Pallis wrote 16 years ago16:
"Asystole inevitably appears (in a matter of a few days).... The reasons why the heart stops in a short space of time... are complex, but the empirical fact is established beyond doubt".
Similarly, the US Presidential Commission stated:
"Even with extraordinary medical care, these (somatic) functions cannot be sustained indefinitely, usually for no more than several days"17.
Similar statements could be quoted ad nauseam from the literature on brain death.
Such assertions boil down to the following implicit syllogism:
* All bodies without an integrative unit necessarily deteriorate inexorably to imminent cardiovascular collapse despite all therapeutic measures.
* All brain-dead bodies necessarily deteriorate inexorably to imminent cardiovascular collapse despite all therapeutic measures.
* Therefore, all brain-dead bodies lack integrative unity.
This would be a good argument only if the facts were correct and the logic valid. Expressed symbolically, this would be:
* Every X has property Y.
* Every Z has property Y.
* Therefore, all Z is X.
However, even the minor premise is not true. The correct syllogism really is:
* Every X has property Y.
* Not all Z has property Y.
* Therefore, at least some Z's are not X.
In a recently published study I collected approximately 175 cases with a diagnosis of brain death who survived more than one week18 . Most were collected from the professional literature, a few from the media speech, and a few from experience staff or from the communications of other neurologists. Fifty-six cases have sufficient individual information for a goal-statistical analysis.
Here is the record of survival curves for the whole group, as well as for the two subgroups distinguished by the terminal event: 37 cases survived to spontaneous cardiac arrest and of these, 19 had their treatment stopped. More than half of the cases survived more than one month and one third more than two months. Seven survived more than six months and four more than a year, the record is at 16 years and.... is still alive!
Given that most of these cases are in the public domain, it is difficult to understand how Pallis, as recently as 1996, could claim with an impassive face:
"It was clearly established by the early 1980s that no patient in an apnoeic coma who had been declared brain dead from agreement according to the rigorous criteria of the UK code (...) had failed to develop asystole within a relatively short period of time. That fundamental insight remains as valid today as it was twenty years ago, and not just in the UK, but throughout the world"19.
A clear example of manipulation of the facts to fit the theory.
If treatment had not been stopped in the second subgroup, those survivals would have increased by unknown numbers. A statistical technique called the Kaplan-Meier method gave this unique curve representing the probability of survival as a function of time (assuming continued life support): a truer indicator of the intrinsic survivability of the brain-dead body.
An important determinant of survivability turned out to be age. Here is an age distribution at the time of brain death with respect to length of survival in all 56 cases. The longest survivors (2.7 years, 5.1 years and 15 years) were all young children, and the 9 survivors over 4 months were under 18 years of age. In contrast, the 17 patients older than 30 years survived less than 2.5 months. Survival curves demonstrated this age effect with statistical rigour. Young adults and children had relatively long survivals, older adults had shorter survivals and middle-aged adults had intermediate survivals.
Another determinant core topic of survivability turned out to be the cause of brain death. The aetiologies were divided into two categories: primary brain pathology (such as a spontaneous intracranial haemorrhage or a gunshot wound to the head), and diffuse or multisystem damage (such as cardiac arrest or a car accident). That the latter have a more diminished survival than the former makes intuitive sense and is verified by the respective Kaplan-Meier curves.
These data teach us several lessons:
First, brain death does not necessarily lead to imminent cardiac arrest.
Second, the heterogeneity of survival duration can largely be explained by non-brain factors. Moreover, the process of brain damage leading to brain death often induces secondary damage to the heart and lungs. Therefore, the tendency to early cardiac arrest in most brain-dead patients is more attributable to somatic factors than to the mere absence of brain function per se.
Third, the first few weeks are particularly precarious. But those who tend to stabilise do not require sophisticated technological support any longer. Some have even been sent home on a respirator. Although a materialist-reductionist might try to argue (on the basis of the irreversible coma) that these are not human persons, no one can seriously claim that they are not living human organisms, living human beings.
Let me introduce TK, a record survivor. At the age of 4, he contracted meningitis, causing such intracranial pressure that even the bones of his skull split. Multiple brain wave tests showed flat brain waves and no spontaneous breathing or brainstem reflexes were observed for the next 16 years. Doctors suggested discontinuing support, but his mother refused. His first stage was very hard, but he was eventually transferred home, where he remains on a ventilator, assimilates his tube feedings, urinates spontaneously, and requires little more than nursing care. Although brain dead, he has grown, overcome infections and healed wounds.
TK's mother gave me permission to examine him and to document everything photographically. Here you see how his skin became mottled, associated with a rise in heart rate and blood pressure, in response to pinching parts of his body. This nervous response could not be elicited in the face, because the sensory input is processed in the brain stem, which does not exist there.
Although ethical and logistical considerations prevented me from performing a formal apnoea test, the fact remains that he met all but the clinical criteria for brain death. In addition to confirming the diagnosis, evoked potentials showed no cortical or brainstem responses, an MRI angiogram showed no intracranial blood flow, and this striking MRI scan revealed that the entire brain, including the brainstem, had been replaced by disorganised membranes and proteinaceous fluids.
TK has much to teach about the necessity of the brain for integrative somatic unity. There is no doubt that his brain died at the age of 4. Nor is there any doubt that he is still alive at 20.
2. Litany of integrative functions
Another common argument for equating brain death with death is to recite a litany of the integrative functions measured by the brain and exclaim: "How can a body with a dead brain be in any way a unified organism without all of them? Take, for example, the following passage from Bernat20:
"It is primarily the brain that is the manager of the functioning of the organism as a whole: the integration of organ and tissue subsystems by neural and neuroendocrine control of temperature, fluids and electrolytes, nutrition, respiration, circulation, appropriate responses to danger, among others. The patient with cardiac arrest and destruction of the whole brain is simply a sample of the disintegrated individual subsystems, since the organism as a whole has ceased to function".
But this is not a scientific approach to an empirical question. To determine whether a given body has integrative unity, one must first define the term operationally, and then examine that body for properties relevant to the definition. Surprisingly, this has never been done. As a first step towards that goal, I proposed in another recently published article (Shewmon, 1999a), the following two operational criteria:
Criterion 1: "Integrative unity" is possessed by a given organism (i.e. it really is an organism) if it possesses at least one holistic and emergent level property. A property of a compound is defined as "emergent" if it derives from the mutual interaction of the parts, and as "holistic" if it is not predictable of any part or subset of parts, but only of the whole compound.
Living, healthy organisms normally possess many such properties, while diseased organisms may possess fewer. But only one is sufficient to be an organism, for truly at the level of the whole there must be a unity from which it is predicated.
The second operational criterion is a corollary:
Criterion 2: No body requires less technological attendance to maintain its vital functions than a similar body, which is nevertheless a "living whole", must possess at least the same integrative unitary force and thus also be a "living whole".
Clearly, many brain-dead bodies in the Intensive Care Unit require less technological support than many other extremely ill or dying patients in those same units, who are nonetheless still alive. Ergo, those brain-dead patients, with even more integration, must be alive as well.
But let us return to the litany of integrative functions in the light of criterion 1. On closer inspection, one discovers that:
* most brain-mediated integrative functions are not somatically integrative; and, conversely, most brain-mediated integrative functions are not somatically integrative; and, conversely,
* most somatically integrative functions are not mediated by the brain.
Moreover, some "integrative functions" core topic, if understood as brain-mediated, are not somatically integrative, and if understood as somatically integrative, are not brain-mediated.
Consider the breathing and nutrition cited by Bernat. If "breathing" is understood as "moving air in and out of the lungs", then breathing is coordinated by the brainstem. However, if "breathing" is understood in the technical sense of exchange of oxygen and carbon dioxide (more relevant to the integrative unit), then it is a function Chemistry of the mitochondria in every cell of the body.
Similarly, if "nutrition" is understood as eating, it is certainly coordinated by the brain. However, if it is understood as the breakdown and assimilation of nutrients for energy and body structure (the only sense relevant to somatic integration), then it is a function Chemistry of every cell in the body.
Another irony is this. Although neurologists often cite impending cardiovascular collapse to justify the equivalence between brain death and death, the most recent diagnostic guidelines of the American Academy of Neurology state that "normal blood pressure without pharmacological support" is explicitly "compatible with the diagnosis"21.
Furthermore, heart transplant surgeons agree with agreement that "most donors can be successfully weaned from pharmacological support by administering plasma expanders22 and that cardiovascular stability is a second-order requirement for heart donors. Thus, the feature intended to ensure that heart donors are dead is itself a relative contraindication to heart donation; and, conversely, the best hearts for transplantation come from donors with intrinsic somatic integration that is not derived from the brain.
Moreover, although the most common explanation for equating brain death with death is the loss of the integrative unit, the official diagnostic criteria:
- do not require the absence of a single somatically integrative brain function, and
- explicitly, they allow the preservation of some somatically integrative functions, for example:
(a) posterior pituitary/hypothalamic function
(b) cardiovascular stability
(c) autonomic and endocrine responses to skin incision without anaesthesia.
Moreover, there is an impressive, parallel litany of somatically non-brain-mediated integrative functions, most (if not all) of which are properties of the set that meet Operational Criterion 1:
* homeostasis of an unlimited variety of physiological parameters and chemicals;
* assimilation of nutrients;
* removal, detoxification and recycling of cellular waste;
* energy balance;
* maintenance of body temperature (although below normal);
* wound healing;
* fight against infections and foreign bodies;
* development of a febrile response to infection (although rare);
* Cardiovascular and hormonal stress responses to organ removal incision;
* sexual maturation, as in 2 children among the pool of prolonged survivors;
* successful gestation of a foetus, as in 12 women in the cohort;
* and proportional growth, as in 3 children from group;
In addition to meeting Operational Criterion 1, the following also meet Criterion 2:
* recovery and stabilisation following cardiac arrest and other complications;
* spontaneous improvement in general health, such as loss of need for vasopressor medication, return to mobility gastrointestinal allowing tube feeding, etc.
* ability to maintain fluid and electrolyte balance with only sporadic monitoring and adjustments;
* and full survivability with minimal medical intervention outside the hospital (as in 7 of the cases I studied).
Why should all these functions that do not require the brain be selectively ignored, when they are truly more somatically integrative than brain-mediated functions?
Far from constituting a central integrator, without which the body is reduced to a mere bag of organs, the brain serves as a modulator, fine tuner, optimiser, strengthener and protector of an implicitly already existing and intrinsically mediated somatic unity.
3. Somatic physiological equivalence with the high spinal cord section
Many more considerations could be made, but time does not permit. Let me just mention, however, one that I consider to be a definitive physiological argument in the discussion on somatic unity in brain death. This has also been recently published23. Section of the upper spinal cord largely eliminates the co-ordinating influence of the brain on the body, maintaining only the function of the vagus nerve and the pituitary gland. Sometimes the function of the vagus nerve has to be pharmacologically suppressed to treat bradycardia, which is common in upper spinal cord injuries. And we can even imagine that the victim is an endocrinological patient with medically compensated panhypopituitarism. The effect on somatic physiology of such a disconnection from the brain could be virtually identical to that of brain death. If the brain were the critical integrating and unifying organ, the body should disintegrate in the absence of its controlling influence, and the effect on the body should be the same if such absence of control were due to the destruction or simple disconnection of the brain.
A detailed comparison between the somatic clinical symptoms of brain death and upper cervical lesions shows that brain-dead bodies are, in principle and clinically, as much "organism as a whole" as bodies with spinal cord section. Therefore, whatever definition we choose to give to concepts such as "integrative unit" and "organism as a whole", if they can be appropriate for spinal cord-sectioned bodies, they should necessarily be appropriate for brain-dead bodies (the only difference is that one is conscious and the other is comatose, but we have already seen how this is not a determining factor in distinguishing life from death).
But if brain death is not death, what is it? We turn once again to the three conceptual levels: definition, anatomical criteria and clinical tests.
Now, the basic definition remains the same: the loss of integrative somatic unity.
The anatomical criterion, however, becomes a critical Degree of damage on a molecular scale throughout the body, beyond a thermodynamic "point of no return". The body's tendency to active self-maintenance is irreversibly lost, and physico-chemical processes now follow the path of increasing entropy characteristic of inanimate things.
Now, a sine qua non condition of the civil service examination to entropy is energy, generated by respiration Chemistry, and a sine qua non condition of somatic integration is blood circulation, by which the body parts interact with each other. Therefore, a clinical indicator for the "point of no return" is the sustained cessation of oxygenated blood circulation. The critical duration depends on body temperature; ordinarily, probably around 20 to 30 minutes.
Although "circulatory-respiratory" sounds similar to the old-fashioned "cardio-pulmonary", they are not synonyms. Neither spontaneous heartbeat nor respiration are essential for life, but circulation and respiration Chemistry are. Therefore, the proposal of a circulatory-respiratory standard represents, far from a reactionary regression, actually a conceptual advance, bringing our judgement and evidence more in line with the basic concept.
V. What difference does it make?
Although "brain death" is a legal fiction, it has produced much good and no apparent harm. So why fight it? I see five reasons:
First, many professionals in various parts of the world involved in transplantation have confused ideas about whether brain-dead donors are dead. Thus, their consciences may be subliminally compromised by a sense of participation in a utilitarian death. Moreover, among the general public, the widespread perception that society approves of killing certain dying patients for a good enough cause may be contributing to the damage to respect for life. The removal of viscera from living patients with destroyed brains may therefore be causing far greater harm to doctors, nurses and society than to the organ donors themselves.
Second, the traditional explanation of brain death has become increasingly implausible. But as brain death is falsely regarded as a sacred cow of bioethics that must be preserved at all costs, theorists have increasingly clung to the only coherent argument left, namely that of loss of personhood in a reductionist sense. Consequently, the praxis of brain death is beginning to evolve in that direction rather than along the lines of the sanctity of human life. For example, proposals to use living anencephalic children or patients in a vegetative state as organ sources, unthinkable only a few years ago, are now taken seriously among intellectuals and in the medical literature.
Third, the notion of "brain death" has inspired the invention of its supposed mirror image called "brain life" to justify abortion and experimentation on human embryos. Although the idea of "brain life" is contradicted by the consideration of integrative unity, it is logically derived from the reductionist approach of personality consciousness, which has gradually become the de facto explanation for brain death.
Fourth, there is a serious problem of informed consent. Most signatories to organ donor cards and families authorising donation have very little knowledge about brain death and what actually happens in operating rooms. When they read the phrase "after my death", many imagine a pulseless corpse and may be horrified to learn that it actually means "after I am comatose and not breathing, but all my other organs are functioning well", and that "I will be eviscerated while my heart is still beating spontaneously". Moreover, no one is informed that the explanation for equating brain death and death remains controversial and that the accumulating empirical evidence casts serious doubts on it. Thus, information highly relevant to the moral decision of the potential donor is systematically withheld.
Finally, for the state to define someone as legally dead from agreement with a criterion contrary to that person's deeply held convictions violates freedom of religion and other fundamental rights (I am thinking particularly of orthodox Jews, but also of anyone who rejects brain death on non-religious grounds). Only a legal circulatory-respiratory definition can be universally accepted.
These, then, are my reasons for challenging the dogma of brain death. The ethical consequences of withdrawal of the concept of brain death mainly affect the field of organ transplantation. There is no moral problem in disconnecting the respirator from a patient with a totally destroyed brain. My study of cases of prolonged survival has as its goal main purpose to delve into the somatic physiology of brain death; in no way did it represent an implicit defence of "vitalism". In no clinical context is it more evident that the use of life-support techniques is morally "extraordinary" or "disproportionate".
The implications for organ transplantation are much more complex than they appear at first sight. A detailed exhibition would require us to extend beyond what is reasonable on this lecture. Suffice it to say that I am not against vital organ transplantation and that I sincerely believe that there are other ways, which do not necessarily involve equating brain death with death and removing the heart while it is still beating, to give it a moral justification and to carry it out at internship. In particular, the use of the concept of the "non beating heart donor" not only requires such equating, but may even make many more organs available for transplantation than if we were to require all potential donors to be brain dead. In fact, in a historical context, this was the way in which the first heart24 and liver25 transplants were performed, long before brain death was elevated to legislative altars. In the last decade, in fact, we have witnessed a resurgence of interest and, consequently, of research in this line26. There is not time to elaborate on this topic, but let me emphasise that I believe that organ transplantation is in principle a laudable internship , and that I believe that there are ways to do it without directly causing the death of the donor, even if we admit that brain death is not equivalent to death. This is certainly a very promising area for the research, both technically and ethically. In any case, I am convinced that replacing brain death with a scientifically more credible concept would significantly promote respect for life.
Notes
(1) D.A. Shewmon, Recovery from brain death: A neurologist's Apologia, in Linacre Quarterly, 1997, 64, 30-96.
(2) D. A. Shewmon, Brain stem death, brain death and death: a critical revaluation of the purported evidence, in "Issues in Law and Medicine", 1998, 14, 125-45.
(3) D.A. Shewmon, Disputed question #1: Is it reasonable to use as basis for diagnosing death the UK protocol for the clinical diagnosis of "brain-stem death"?, in L. Gormally ed., Issues for a catholic Bioethic Proceedings of the International Conference to celebrate the Twentieth Anniversary of the foundation of the Linacre Centre. 28-31 July 1997, The Linacre Centre, London, 1999, 315-333.
(4) D.A. Shewmon, "Brain death": a valid theme with invalid variations, blurred by semantic ambiguity, in R.J. White, H. Angstwurm and I. Carrasco de Paula, Working Group on the Determination of Brain Death and its Relationship to Human Death. Carrasco de Paula, Working Group on the Determination of Brain Death and its Relationship to Human Death, Ed. by Pontifical Academy of Sciences, Vatican City (10-14 December1989), 1992, 23-51; S.J. Youngner, C.S. Landefeld, C.J. Coulton, B.V. Juknialis, M. Leary, "Brain death" and organ retrieval. A cross-sectional survey of knowledge and concepts among health professionals, in "JAMA", 1989, 261, 2205-10.
(5) John Paul II, Evangelium Vitae (The Gospel of Life), St. Paul Books and average, Boston MA, 1995.
(6) J.L. Bernat, C.M. Culver, B. Gert, On the definition and criterion of death, in Ann Intern Med, 1981, 94, 389-94.
(7) Pius XII, The pronlongation of life. Address to an International Congress of Anesthesiologists, in "The Pope Speaks", 1958, 4, 393-8.
(8) H. Denzinger, The Sources of Catholic Dogma Enchiridion Symbolorum], (Translated by R.J. Deferrari), Herder Book Co, St. Louis, 1957.
(9) John Paul II, Determining the moment of death. Address of Pope John Paul II to participants in a congress on the determination of the moment of death, in "The Pope Speaks", December 14, 1989, 35, 207-11.
(10) J.L. Bernat, C.M. Culver, B. Gert, On the definition and criterion of death, in "Ann Intern Med", 1981, 94, 390.
(11) R. Hassler R, Basal ganglia systems regulating mental activity, in Int J Neuro, 1977, 12, 53-72.
(12) D.A. Shewmon, The metaphysics of brain death, persistent vegetative state, and dementia, in "The Thomist", 1985, 49, 24-80.
(13) D.A. Shewmon, G.L. Holmes, Brainstem plasticity in congenitally decerebrate children (abstract), in "Brain & Devel", 1990, 12, 664.
(14) D.A. Shewmon, G.L. Holmes, P.A. Byrne, Consciousness in congenitally decorticate children: "developmental vegetative state" as self-fulfilling prophecy, in "Dev Mec Child Neurol", 1999, 41, 1-11.
(15) D.A. Shewmon, "Brain death": a valid theme with invalid variations, blurred by semantic ambiguity, in R.J. White, H. Angstwurm and I. Carrasco de Paula, Working Group on the Determination of Brain Death and its Relationship to Human Death. Carrasco de Paula, Working Group on the Determination of Brain Death and its Relationship to Human Death, Ed. by Pontifical Academy of Sciences, Vatican City (10-14 December 1989), 1992, 23-51.
(16) C. Pallis, Whole-brain death reconsidered - physiological facts and philosophy, in "J Med Ethics", 1983, 9, 35-36.
(17) President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research, Defining Death: Medical, Legal and Ethical Issues in the Determination of Death, U.S. Government Priting Office, Washington, 1981, 35.
(18) D.A. Shewmon, Chronic "braindeath": goal-analysis and conceptual consequences, "Neurology", 1998, 51, 1538-45; D.A. Shewmon, (reply to letters), in "Neurology", 1999, 53, 1371-2.
(19) C. Pallis, D.H. Harley, ABC of Brainsteam Death, BMJ Publishing Group, London, 1996, preface to the 2nd edition.
(20) J.L. Bernat, The definition, criterion, and statute of death, in "Semin Neurol", 1984, 4, 48.
(21) American Academy of Neurology, Quality Standards Subcommittee, Practice parameters for determining brain death in adults (Summary statement), in Neurology, 1995, 45, 1012-4.
(22) J.M. Darby, K. Stein, A. Grenvik, S.A. Stuart, Approach to management of the heartbeating 'brain dead' organ donor, 1989, JAMA, 261, 2222-8; W.G. Guerriero, Organ transplantation, in R.K. Narayan, J.E. J. Wilberger and J.T. Povlishock (eds.), Neurotrauma, McGraw-Hill, New York, 1996, 835-40.
(23) D.A. Shewmon, Spinal shock and "brain death": somatic pathophysiological equivalence and implications for the integrative-unity rational, in "Spinal Cord", 1999, 37, 313-24.
(24) C.N. Barnard, The operation. A human cardiac transplant: an interim report of a successful operation performed at Groote Schuur hospital, Cape Town, in "S Afr Med J", 1967, 41, 1271-4.
(25) T.E. Starzl, C.G. Groth, L. Brettschneider, I. Penn, V.A. Fulginiti, J. Moon, et al., Orthopic homotransplantation of the human liver, "Ann Surg", 1968, 168, 392-415.
(26) R.M. Arnold, S.J. Youngner, R. Schapiro, C.M. Spicer (eds.), Procuring organs for transplant: the discussion over non-heart-beating cadaver protocols, The Johns Hopkins University Press, Baltimore, 1995.