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Commentary on guidelines for the determination of brain death in children.

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ISSUES I N CLINICAL NEUROSCIENCE
Commentary on
Guidelines for the
Determination of
Brain Death in Children
D. Alan Shewmon. MD
To many pediatric neurologists called upon to diagnose brain death in young children, the recent publication of official guidelines in five major journals must
have been welcome El}. But it would be a mistake to
imagine that this was a relatively straightforward issue
that the joint Task Force has now definitively resolved.
The following two questions are central to the establishment of diagnostic criteria for brain death at any
age: (1) what degree of diagnostic certitude should a
declaration of death require, and (2) what is the risk of
false-positive error associated with a given diagnostic
criterion?
As for the former, society and the medical profession have always recognized a distinction between a
prognostication of probable fatality and a pronouncement of death. The ethical import of this distinction
depends on its context. In the case of withdrawal of
life-sustaining treatment, decision-mkng is based
upon relative benefits and burdens {2]: brain death has
never been a prerequisite for the withdrawal of such
treatment, although for a few years there was some
legal confusion in this regard. This is also why, until
very recently, there was no need to determine brain
death in infants.
In the context of organ transplantation, however,
the distinction between a poor neurological prognosis
and brain death is universally recognized as not only
conceptually valid but also ethically crucial. It is one
thing for a physician to allow death to occur naturally
and quite another directly to cause unnatural death by
organ removal. Thus, the Uniform Anatomical Gift
Act requires that donors of vital organs be actually, not
probably, dead [31. Similarly, the President’s Commission emphasized that the determination of death requires a truly negligible risk of false-positive error,
unlike most other lunds of medical diagnoses [4, pp
22, 81-83, 1611, and the medical literature concerning
brain death in older children and adults is replete with
statements to the same effect. With this concern in
mind, “medical experts testified to the Commission
From the Division of Pediatric Neurology, UCLA Medical Center,
Los Angeles, CA. Dr Shewmon is a past member of the Ethics
Committee of the Child Neurology Society, and Chairman of the
Infant Care Review Committee of UCLA Medical Center.
Address correspondence to Dr Shewmon, Division of Pediatric
Neurology, UCLA Medical Center, MDCC 22-464, Los Angeles,
CA 90024-1752.
that the risk of mistake in a competently performed
examination was infinitesimal” [4, p 291. Along the
same lines, if the American Medical Association’s
(AMA’s) Principles of Medical Ethics require for the
mere withdrawal of life-prolonging treatment that “a
patient’s coma is beyond doubt irreversible and there
are adequate safeguards to confirm the accuracy of the
diagnosis” {51, then a fortiori the determination of
death of an organ donor should be at least as much
“beyond doubt.”
In this light, it would have been of great interest had
the Task Force stated its own opinion concerning the
degree of certitude of death requisite for the ethical
removal of vital organs. If it regards the President’s
Commission’s and the AMA’s standards as excessively
strict, then we deserve to know what probability of
diagnostic error it considers acceptable, and why. Only
then can we assess whether its guidelines measure up
to its own ethical standards.
This leads to my second question: what, in fact, is
the risk of false-positive error associated with the
guidelines, particularly for ages 1 week to 2 months?
The number of reported cases that would have fulfilled
the guidelines and had autopsy proof of brain death is
unclear from the literature but certainly extremely
small (eventual death constituting a spurious endpoint
for validating that death had already taken place). The
Task Force wisely did not hazard to extend the diagnosable age range below 1 week post-term, on account
of the absence of any data base; it is therefore difficult
to understand the consistency in confidently setting
forth criteria for infants between 1 week and 2
months, when the relevant data base is barely any
larger.
Moreover, the neonatal literature contains counterexamples for virtually all the individual elements
of the proposed criteria, as excellently summarized
by Volpe [6}. The contention of some members of
the Task Force that there has so far been no counterexample that combines these elements, even if true,
provides little reassurance given the paucity of cases
in general. In the context of doubt concerning the
death of a potential organ donor, however, the burden
of proof is on those who assert death, not on those
who question it. Although Volpe maintains that brain
death can be established by a “demonstration that the
cessation of brain functions persists for an appropriate
period of observation” {G, p 2931, nowhere does he
suggest how to determine “an appropriate period of
observation,” nor give any reason to conclude that the
observation periods set forth in the guidelines are in
fact “appropriate.”
Specifically, there is no data base that justifies the
contention that “irreversible cessation of all functions
of the entire brain, including the brainstem” can be
confidently determined by mere absence of function
Copyright 0 1988 by the American Neurological Association
789
for the following periods of time (“confirmation” by
radionuclide scan being merely optional): 48 hours of
clinical and electroencephalographic (EEG) findings
between 7 days and 2 months of age, 24 hours of
clinical and EEG findings between 2 months and 1
year, and 12 hours of plain “observation” over 1 year
“when an irreversible cause exists.” (Is this latter
phrase merely a poor choice of words for “when a
cause of irreversibility is known”? Isn’t it the loss of all
brain functions, not the cause of that loss, that is supposed to be irreversible? Besides, if irreversibility is
already known to exit, why require 12 hours of observation?) If an “irreversible cause” does not exist (particularly with hypoxic-ischemic encephalopathy), then
24 hours of purely clinical observation supposedly
suffices in children over 1 year. This observation time
may be reduced by appropriate findings on EEG or
radionuclide scan. For all these ages, however, if one
takes seriously the distinction between brain death and
neocortical death, as do the President’s Commission
and most state laws, one must admit that neither 24 to
48 hours of absent brainstem reflexes, nor electrocerebral silence, nor absence of supratentorial blood
flow establishes irreversibility of brainstem nonfunction; thus they do not establish brain death.
But what can logically be inferred from the absence
of a counterexample to these criteria, given the paucity
of clinical experience? It is possible to calculate, by
means of Bayesian probability theory, the risk of falsepositive error for a putative criterion, given no information other than a 100% association with proven
brain death in N patients so far 171. That risk is
1/(N+2). If the time course of return of function in
similar but non-brain-dead comatose patients were also
known, the N required for negligibility of error could
be made realistic, but at the expense of requiring a
uselessly long observation time 181; but such information is not available for infants, so we are left with
1/(N 2 ) as the false-positive risk.
My concern with the Task Force’s guidelines is
therefore not a mere quibble over the difference between a risk of one in a million and absolute mathematical certitude. For the age range between 1 week
and 2 months, the relevant N is unknown but certainly
not greater than 40; thus, there is no reason to believe
that the theoretical false-positive risk is any less than
1/42. Of course, it is possible that future experience
could increase the N , but even so, l / ( N + 2 ) would
never begin to approach what most people might consider “negligible.”
The point here is not that we must be so diagnostically certain as to preclude even Lazarus-like miracles;
it is merely that the death of infant organ donors
should be declared with no less certainty than that of
adult donors. Significantly, the Task Force itself does
not even claim that the proposed criteria are valid, but
merely that they are “useful.”
+
790 Annals of Neurology Vol 24
The official promulgation of unvalidated and ques
tionably reliable guidelines not only fails to solve the
original diagnostic problem, but creates still new problems. Now that the guidelines are irrevocably entrenched in the literature, they will tend to become
a self-fulfilling prophecy, and the uniform nonsurvival
of organ donors accordingly declared “dead” will be
falsely held up as increasing evidence for their validity.
Moreover, it will now become much more difficult to
conduct a scientific study of infant brain death criteria,
because it will seem unethical to prolong artificial life
support or to prohibit organ donation from a “dead”
infant, for the sake of a research protocol.
Just as the diagnosis of brain death in individual
cases should be made by physicians independent of the
transplant team {S], so should official diagnostic guidelines be formulated independently of urgent pressure
from the field of transplantation. The very existence of
such pressure constitutes much more reason for the
dissemination of official caveats and admissions of current ignorance than for the promulgation of arbitrary
and unvalidatable specific criteria. Unfortunately, it
will now be extremely difficult to correct the false
sense of diagnostic security conveyed to the medical
community by the fanfare afforded the recent guidelines. Hopefully, pediatric neurologists will maintain a
sense of personal responsibility for their own diagnostic accuracy and not simply delegate it to the Task
Force by relying uncritically on the guidelines.
I am hardly suggesting that brain death can never be
diagnosed in infants, but rather that the diagnostic criteria should be more reliable than mere absence of
function for some arbitrary period of time {9].Criteria
with self-evident validity do in fact exist, for example,
the sequence of signs (unfortunately uncommon in
brain-dead infants) that are pathognomonic of completed rostral-caudal herniation due to a known cause,
or the absence of all intracranial blood flow on contrast
angiography (proposed by Kricheff and colleagues
{lo] and Coulter [11] as the only reliable criterion in
infants). Although contrast angiography involves various logistical inconveniences, these do not seem disproportionate to the other logistical and technological
efforts inherent in organ transplantation. Moreover, a
demonstration of absent blood flow to the entire brain
has the additional advantage of enabling a much earlier
declaration of death than is permitted by the guidelines, whose requisite observation times could in some
cases hamper a transplantation procedure much more
than would the transporting of the potential donor to
an angiography suite.
References
No 6 December 1988
1. Task Force for the Determination of Brain Death in Children.
Guidelines for the determination of brain death in children.
Ann Neurol 1987;21:616-617; Arch Neurol 1987;44:587588; Neurology 1987;37:1077-1078; Pediatric Neurology
1987;3:242-243; Pediatrics 1987;80:298-300
2. Hastings Center. Guidelines on the termination of lifesustaining treatment and the care of the dying. Briarcliff Manor,
NY: The Hastings Center, 1987
3. The Uniform Anatomical Gift Act of 1968, 8 U.L.A. 15 (1972)
4. 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. Washington, DC: U.S. Government Printing Office,
1981
5. Council on Ethical and Judicial Affairs. Current opinion of the
council on ethical and judicial affairs of the American Medical
Association-1986.
Chicago: American Medical Association,
1986: #2.18, p 12
6. Volpe JJ. Brain death determination in the newborn. Pediatrics
1987;80:293-297 (Commentary)
7. Shewmon DA. The probability of inevitability: the inherent
impossibility of validating criteria for brain death or “irreversibility” through clinical studies. Stat Med 1987;6:535-554
8. Shewmon DA. The critical duration beyond which electrocerebral silence may he considered “irreversible.” J Clin Neurophysiol 1987;4:266-267
9. Shewmon DA. Caution in the definition and diagnosis of infant
brain death. In: Thomasma DC, Monagle JF, eds. Medical ethics: a guide for health professionals. Rockville, MD: Aspen Publishers, 1987;38-57
10. Kricheff 11, Pinto RS, George AE, et al. Angiographic findings
in brain death. Ann N Y Acad Sci 1978;315:168-183
11. Codter DL. Neurologic uncertainty in newborn intensive care.
N Engl J Med 1987;3 16:840-844
Task Force on Brain Death in Children+
‘George J. Annas, JD, Patrick F. Bray, MD,
Donald R. Bennett, MD, Lester L. Lansky, MD,
Edwin C. Myer, MD, Karin Nelson, MD,
Russell C. Raphealy, MD, Sanford Schneider, MD,
David A. Stumpf, MD, PhD, and Joseph J. Volpe, M D
Two critiques of the Task Force’s guidelines for brain death
in children have appeared [ I f , one in this issue of Annals
(see p 789).The Task Force was aware of these individuals’
opinions and had considered them prior to drafting the final
document 121. The organizations that endorsed the guidelines were also advised of these alternate opinions, and they
were openly discussed in a public forum of the Child Neurology Society and the Section of Neurology of the American Academy of Pediatrics.
The Task Force wrote a document based on scientific observations and not mere opinion. The Task Force realizes
that, for some issues, the published data base is relatively
small; to it, we added our own experiences and the information from writings on older individuals with brain death. The
issue of certainty is important. Medicine is not an exact science. Criteria for death have never been exact, as illustrated
by the past use of bells and other devices on coffins. We are
not aware of any examples of individuals who met the Task
Force’s criteria for brain death who have survived, and the
critics have presented none. The counterexamples offered
do not fulfill the combination of criteria necessary. We also
realize that these counterexamples were published precisely
because they were exceptional cases that needed t o be considered, and they were carefully considered. The population
from which these unusual patients were selected is large.
The Task Force did not consider issues surrounding organ
donation as important in its deliberations. Indeed, the Task
Force strongly embraced the philosophy that brain death
determinations should be separated from other issues.
The Task Force document is not the final word on brain
death in children. When these guidelines were originally
contemplated, it was agreed by the Task Force members that
a major thrust was to open the door to dialogue, on the
assumption that guidelines were evolving and continually
changing. Indeed, if one of the offshoots of the guidelines’
publication is an increase in discussion and prospective studies, we will have achieved an important goal. W e hope, as
more data are generated, that refinements can be introduced.
In the meantime, the Task Force reaffirms its opinion that
the published guidelines can be applied.
The critiques are offered by compassionate and concerned
physicians. The issue is obviously thorny to them, and understandably so, given their perspective. W e suggest that attempts to formalize scientific thinking in the clinical arena
can be done with sensitivity and compassion. We believe
physicians should bring the Art, as well as the Science, to the
bedsides of these patients.
References
1. Freeman JM, Ferry PC. New brain death guidelines in children:
further confusion. Pediatrics 1988;81:30 1-303
2. Task Force on Brain Death in Children. Guidelines for the determination of brain death in children. Ann Neurol 1987;21:616617; Arch Neurol 1987;44:587-588; Neurology 1987;37:
1077-1078; Pediatric Neurology 1987;3:242-243; Pediatrics
1787;80:298-297
Issues In Clinical Neuroscience
791
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