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- Contemporary controversies in the definition of death.
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Some who regard a general definition of death as unnecessary have focused on consideration 2 in defending the whole-brain standard. Some others, as discussed later, have retained consideration 1 but dropped consideration 2. An additional consideration that has been influential, yet is logically separable from the other two, is 3 the thesis that the whole-brain standard updates, without replacing, the traditional approach to defining death. According to the organismic definition, death is the irreversible loss of functioning of the organism as a whole Becker ; Bernat, Culver, and Gert Proponents of this approach emphasize that death is a biological occurrence common to all organisms.
Although individual cells and organs live and die, organisms are the only entities that literally do so without being parts of larger biological systems. Ideas, cultures, and machines live and die only figuratively; cells and tissues are literally alive but are parts of larger biological systems. So an adequate definition of death must be adequate in the case of all organisms. What happens when a paramecium, clover, tree, mosquito, rabbit, or human dies? The organism stops functioning as an integrated unit and breaks down, turning what was once a dynamic object that took energy from the environment to maintain its own structure and functioning into an inert piece of matter subject to disintegration and decay.
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In the case of humans, no less than other organisms, death involves the collapse of integrated bodily functioning. The whole-brain standard does not follow straightforwardly from the organismic conception of death. One might insist, after all, that a human organism's death occurs upon irreversible loss of cardiopulmonary function.
Why think the brain so important? According to the mainstream whole-brain approach, the human brain plays the crucial role of integrating major bodily functions so only the death of the entire brain is necessary and sufficient for a human being's death Bernat, Culver, and Gert Although heartbeat and breathing normally indicate life, they do not constitute life. Life involves integrated functioning of the whole organism. Circulation and respiration are centrally important, but so are maintenance of body temperature, hormonal regulation, and various other functions—as well as, in humans and other higher animals, consciousness.
The brain makes all of these vital functions possible. Their integration within the organism is due to a central integrator, the brain. This leading case for the whole-brain standard, then, consists in an organismic conception of death coupled with a view of the brain as the chief integrator of interdependent bodily functions. Another consideration sometimes advanced in favor of the whole-brain standard positions it as a part of time-honored tradition rather than a departure from tradition. The argument may be understood either as an appeal to the authority of tradition or as an appeal to the practicality of not departing radically from tradition.
The claim is that the traditional focus on cardiopulmonary function is part and parcel of the whole-brain approach, that the latter does not revise our understanding of death but merely updates it with a more comprehensive picture that highlights the brain's crucial role:. According to this view, when the entire brain is nonfunctional but cardiopulmonary function continues due to a respirator and perhaps other life-supports, the mechanical assistance presents a false appearance of life, concealing the absence of integrated functioning in the organism as a whole. The whole-brain approach clearly enjoys advantages.
First, whether or not the whole-brain standard really incorporates, rather than replacing, the traditional cardiopulmonary standard, the former is at least fairly continuous with traditional practices and understandings concerning human death. Indeed, current law in the American states incorporates both standards into disjunctive form, most states adopting the Uniform Determination of Death Act UDDA while others have embraced similar language Bernat , The close pairing of the whole-brain and cardiopulmonary standards in the law suggests that the whole-brain standard does not depart radically from tradition.
The present approach offers other advantages as well. For one, the whole-brain standard is prima facie plausible as a specification of the organismic definition of death in the case of human beings.
Another practical advantage is permitting, without an advance directive or proxy consent, discontinuation of costly life-support measures on patients who have incurred total brain failure. While most proponents of the whole-brain approach insist that such practical advantages are merely fortunate consequences of the biological facts about death, one might regard these advantages as part of the justification for a standard whose defense requires more than appeals to biology see subsection 4. The advantages proffered by this approach contributed to its widespread social acceptance and legal adoption in the last few decades of the 20 th century.
As mentioned, every American state has legally adopted the whole-brain standard alongside the cardiopulmonary standard as in the UDDA. It is worth noting, however, that a close cousin to the whole-brain standard, the brainstem standard , was adopted by the United Kingdom and various other nations. According to the brainstem standard—which has the practical advantage of requiring fewer clinical tests—human death occurs at the irreversible cessation of brainstem function.
One might wonder whether a person's cerebrum could function—enabling consciousness—while this standard is met, but the answer is no. Importantly, outside the English-speaking world, many or most nations, including virtually all developed countries, have legally adopted either whole-brain or brainstem criteria for the determination of death Wijdicks Moreover, most of the public, to the extent that it is aware of the relevant laws, appears to accept such criteria for death ibid.
Opponents commonly fall within one of two main groups. One group consists of religious conservatives—and, recently, a growing number of secular academics—who favor the cardiopulmonary standard, according to which one can be brain-dead yet alive if assisted cardiopulmonary function persists.
Contemporary controversies in the definition of death.
The other group consists of those liberal intellectuals who favor the higher-brain standard to be discussed , which, notably, has not been adopted by any jurisdiction. The widespread acceptance in the U. Yet this near-consensus has been broader than it is deep.
Following are several major challenges to the whole-brain standard—and, implicitly, to the brainstem standard. Several additional challenges are implicit in arguments supporting the higher-brain approach. The first challenge is directed at proponents of the whole-brain approach who claim that its standard merely updates, without replacing, the traditional cardiopulmonary standard.
A major contention that motivates this thesis is that irreversible cessation of brain function will quickly lead to irreversible loss of cardiopulmonary function and vice versa. But extended maintenance on respirators of patients with total brain failure has removed this component of the case for the whole-brain standard PCB , The remaining challenges to the whole-brain approach are not specifically directed to those who assert that its standard merely updates the traditional cardiopulmonary standard.
First, in the case of at least some members of our species, total brain failure is not necessary for death. After all, human embryos and early fetuses can die although, lacking brains, they cannot satisfy whole-brain criteria for death Persson , 22— An advocate could respond by introducing a modified definition: In the case of any human being in possession of a functioning brain , death is the irreversible cessation of functioning of the entire brain.
While this may be practically useful in the world as we know it for the foreseeable future, this definition is not conceptually satisfactory if it is possible in principle for some human beings with brains that is, who have functioning brains at any point in their existence to die without destruction of their brains. But suppose we develop the ability to transplant brains.
The thought-experiment that follows appears in McMahan, Recall that the whole-brain standard is generally thought to receive support from an organismic definition of death. But such a conception of human death, one could argue, only makes sense on the assumption that we are essentially human organisms see discussion of the essence of human persons in section 2.
Anaesthesia-Database: The Definition of Death: Contemporary Controversies
According to the present critique, the brain is merely a part of the organism. Suppose the brain were removed from one of us, and kept intact and functioning, perhaps by being transplanted into another, de-brained body. Bereft of mechanical assistance, the body from which the brain was removed would surely die. But this body was the living organism, one of us. So, although the original brain continues to function, the human being, one of us, would have died. Total brain failure, then, is not strictly necessary for human death. A possible rebuttal to this challenge from one who accepts that we are essentially organisms is to argue that the existence of a functioning brain is sufficient for the continued existence of the organism van Inwagen , —, — If so, then in the imagined scenario the original human being would survive the brain transplant in a new body.
Thus, the rebuttal concludes, it is false that a human being could die although her brain continued to live. Perhaps more threatening to the whole-brain approach is the growing empirical evidence that total brain failure is not sufficient for human death —assuming the latter is construed, as whole-brain advocates generally construe it, as the breakdown of organismic functioning mediated by the brain. Many of our integrative functions, according to the challenge, are not mediated by the brain and can therefore persist in individuals who meet whole-brain criteria for death by standard clinical tests.
Such somatically integrating functions include homeostasis, assimilation of nutrients, detoxification and recycling of cellular wastes, elimination, wound healing, fighting of infections, and cardiovascular and hormonal stress responses to unanesthetized incisions for organ procurement ; in a few cases, brain-dead bodies have even gestated a fetus, matured sexually, or grown in size Shewmon ; Potts It has been argued that most brain functions commonly cited as integrative merely sustain an existing functional integration, suggesting that the brain is more an enhancer than an indispensable integrator of bodily functions Shewmon Moreover, several studies have demonstrated that most patients diagnosed as brain dead continue to exhibit some brain functions including the regulated secretion of vasopressin, a hormone critical to maintaining a body's balance of salt and fluid Halevy This hormonal regulation is a brain function that represents an integrated function of the organism as a whole Miller and Truog Another, related problem for the sufficiency of total brain failure for human death arises from reflection on locked-in syndrome.
People with locked-in syndrome are conscious, and therefore alive, but completely paralyzed with the possible exception of their eyes. With intensive medical support they can live. The interesting fact for our purposes is that some patients with this syndrome exhibit no more somatic functioning integrated by the brain than some brain-dead individuals.
Whatever integration of bodily functions remains is maintained by external supports and by bodily systems other than the brain, which merely preserves consciousness Bartlett and Youngner , —6. If total brain failure is supposed to be sufficient for death, and if this is true only because the former entails the loss of somatic functioning integrated by the brain, then the loss of those functions should also be sufficient for death.
But these patients, who are clearly alive, show that this is not so. Either the whole-brain definition must be rejected or this particular reason for accepting the whole-brain approach must be rejected and some other good reason for accepting it found. Recently, a new rationale—distinct from the one that understands human death in terms of loss of organismic functioning mediated by the brain—has been advanced in support of the whole-brain standard PCB , ch. According to this rationale, a human being dies upon irreversibly losing the capacity to perform the fundamental work of an organism, a loss that occurs with total brain failure.
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The fundamental work of an organism is characterized as follows: 1 receptivity to stimuli from the surrounding environment; 2 the ability to act upon the world to obtain, selectively, what the organism needs; and 3 the basic felt need that drives the organism to act as it must to obtain what it needs and what its receptivity reveals to be available ibid, According to a sympathetic reading of the ambiguous discussion in which this analysis is advanced, any patient who meets even one of these criteria is alive and therefore not dead.
A patient with total brain failure meets none of these criteria, even if a respirator permits the continuation of cardiopulmonary function. By contrast, PVS patients meet at least the second criterion through spontaneous respiration a kind of acting upon the world to obtain what is needed: oxygen ; and locked-in patients meet the first criterion if they can see or experience bodily sensation and certainly meet the third insofar as they are conscious.
If one insisted, contrary to the reading deemed sympathetic, that a being must satisfy all three criteria—as robots do not since they lack felt needs—in order to qualify as living, the same may be asserted not only of insentient animal life but also of presentient human fetuses and of unconscious human beings of any age. Another difficulty of the "fundamental work" rationale for the whole brain standard is that it was intended to replace the idea that integrated functional unity within an organism is what constitutes life—but the latter idea is extremely plausible and helps to explain what any "fundamental work" would be working toward cf.
Thomas, Whether any variation or modification of the present rationale for the whole-brain standard can survive critical scrutiny remains an open question. Some traditional defenders of the cardiopulmonary approach believe that the insufficiency of whole-brain criteria for death is evident not only in exceptional cases, such as those described earlier, but in all cases in which patients with total brain failure exhibit respirator-assisted cardiopulmonary function.
Anyone who is breathing and whose heart functions cannot be dead, they claim. The champion of whole-brain criteria may retort that such a body is not really breathing and circulating blood; the respirator is doing the work. The traditionalist, in response, will likely contend that what is important is not who or what is powering the breathing and heartbeat, just that they occur.
Even complete dependence on external support for vital functions cannot entail that one is dead, the traditionalist will continue, as is evident in the fact that living fetuses are entirely dependent on their mothers' bodies; nor can complete dependence on mechanical support entail that one is dead, as is evident in the fact that many living people are utterly dependent on pacemakers. A third major criticism of the whole-brain approach—at least in its legally authoritative formulation in the United States—concerns its conceptual and clinical adequacy.
The whole-brain standard, taken at its word, requires for human death permanent cessation of all brain functions.
Yet many patients who meet routine clinical tests for this standard continue to have minor brain functions such as electroencephalographic activity, isolated nests of living neurons, and hypothalamic functioning see, e. Indeed, the latter, which controls neurohormonal regulation, is indisputably an integrating function of the brain Brody , Now one could maintain the coherence of the whole-brain approach by insisting that the individuals in question are not really dead and that physicians ought to use more thorough clinical tests before declaring death see, e.
But whole-brain theorists tend to agree that these individuals are dead—that the residual functions are too trivial to count against a judgment of death see, e. The emphasis on critical functions, of course, allows one to declare dead those patients with only trivial brain functions. According to this revised whole-brain approach, the critical functions of the organism are 1 the vital functions of spontaneous breathing and autonomic circulation control, 2 integrating functions that maintain the organism's homeostasis, and 3 consciousness.
A human being dies upon losing all three. Whether this or some similar modification of the whole-brain approach adequately addresses the present challenge is a topic of ongoing debate see, e. What seems reasonably clear is that not all functions of the brain will count equally in any cogent defense of the whole-brain approach. The judgment that some brain functions are trivial in this context invites a reconsideration of what is most significant about what the human brain does.
According to an alternative approach, what is far and away most significant about human brain function is consciousness. According to the higher-brain standard, human death is the irreversible cessation of the capacity for consciousness. Reference to the capacity for consciousness indicates that individuals who retain intact the neurological hardware needed for consciousness, including individuals in a dreamless sleep or reversible coma, are alive. One dies on this view upon entering a state in which the brain is incapable of returning to consciousness.
This implies, somewhat radically, that a patient in a PVS or permanent coma is dead despite continued brainstem function that permits spontaneous cardiopulmonary function.