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By Prof Omar Hasan Kasule DrPH Faculty of Medicine, King Fahad
Medical City, Riyadh, Kingdom of Saudi Arabia
ABSTRACT
Objective: This paper
identified ethical issues relating to brain death and analyzed them according
to the purposes of the Law, maqasid al shari’at, and principles of the
law, qawa’id al fiqh, to reach conclusions of practical importance.
Methods: Issues arising
in brain death were selected from articles retrieved from PUBMED over a 10-year
period. Practical and conceptual issues identified in the articles were
analyzed using maqasid al shari’at and qawa’id al fiqh.
Results: Early
determination of death by use of brain death criteria was motivated by the need
to harvest transplantation organs earlier, to save intensive care resources by
earlier cessation of life support, and to obtain tissues for research before
deterioration. These motives would violate the principle of intention which
requires that actions be judged by underlying intentions and that the end does
not justify the means. In this case the nobility of the ends and their public
interest were overriding considerations. The requirements, by the principle of
certainty, of evidence-based proof of death were partially fulfilled by brain
death criteria, tests, and examinations. The principle of custom was partially
fulfilled because there was no universal consensus on criteria of brain death;
the criteria varied by country, by institution, and over time.
Conclusions
and recommendations:
Brain stem death, determined by clinical examination with or without
instrumental confirmation, should remain the mainstay of death definition.
Legal rulings on brain death should be reviewed every 3 years to take into
consideration new developments in medical knowledge and technology.
Key
words: brain death: definition, criteria, guidelines, tests, organ harvesting
Correspondence to: Prof Omar Hasan
Kasule Faculty of Medicine King Fahad Medical City, Riyadh, Kingdom of Saudi
Arabia. Telephone +96612889037 E-mail omarkasule@yahoo.com
Introduction
Death
is a process with a time line and cannot be envisaged as a one-time event with
2 dichotomous states, dead and not dead. There is a need to determine a point
on the timeline of the death process that defines a point of no return after
which the patient enters a rapid irreversible course to ultimate death. Death
in essence is failure of the cardio-respiratory system that transports chemical
nutrients and oxygen needed for the continued life and metabolism of cells. The
sensitivity of cells to oxygen deprivation varies; brain tissue is the most
sensitive and its cells will die earlier that those of other tissues. When the
cardio-respiratory system fails to deliver enough oxygen and nutrients to the
brain, brain cells will die earlier that those of the heart and blood vessels
making brain death an earlier indicator of death than death of the cardiovascular
and respiratory systems. Death of the brain and its vital centers that control
the respiratory and the cardiovascular systems leads to death of these two
systems. We thus end up with a perfect cyclic chicken and egg situation. An
exception to this scenario is brain death due to an electric shock[1]
or cranial trauma that destroys the brain directly.
From
the earliest human history, three indicators of death were known as failure of
the vital systems of the body:
neurological, respiratory, and cardiac. Failure of the neurological
system was recognized as loss of consciousness or coma. The Qur’an described
death of the neurological system in several verses as sakrat al mawt[2],
ghashiyat al mawt[3]
and ghamrat al mawt.[4]
Stopping of chest respiratory movements and lack of air exit from the nose or
mouth were indicators of respiratory failure. Lack of a heart beat or a pulse
were considered indicators of cardiovascular failure. It was also known that
loss of consciousness preceded respiratory and cardiovascular failure. Modern
recognition of brain death as an early indicator of death is therefore not
entirely new. Modern indicators of death are extensions and refinements of
these three using modern medical knowledge. The ‘modern’ indicators are not
static they keep changing with development of new technologies. New indicators
are able to detect the point of irreversible vital organ failure earlier. As
new knowledge and technology develop the point in time at which death can be
pronounced is earlier than before.
The
brain generally dies before other organs because it is very sensitive to injury
and has no potential for recovery or tissue replacement after severe injury.
Irreversible death of the brain will in time result in the death of all other
organs because the brain is the command, coordination, and communication
(C-C-C) center of the bodily functions. Without a functioning brain all bodily
functions will in time disintegrate. The dilemma of modern medical technology
is that it can ‘take over’ the C-C-C functions of the brain by continuing
bodily functions after death of the brain. This gives rise to many ethico-legal
issues the central one being the contrast between ‘supporting life’ versus ‘a
dead corpse with a beating heart’.
This
paper will analyze current practice regarding the determination of brain death
from the perspective of methodological tools based on the purposes of the Law, maqasid
al shari’at, and axioms of the Law, qawa’id al fiqh, and will derive
general rules that can be applied to various situations of and changing
criteria.
Methods
Issues arising in brain death were selected from
articles retrieved from PubMed over a 10 year period by using the key words:
‘brain death’ with ‘diagnosis’, ‘definition’, ‘determination’, ‘guidelines’,
‘criteria’, ‘organ donation’. The practical and conceptual issues identified in
the articles were analyzed using two purposes of the Law, maqasid al
shari’at[5]:
protection of life, hifdh al nafs, and protection of resources, hifdh
al maal as well as three principles of the Law qawa’id al fiqh[6]:
the principle of motive, qa’idat al qasd, the principle of certainty, qa’idat
al yaqiin, and the principle of custom, qa’idat al ‘aadat.
Results
The
Underlying Motives of Brain Death Criteria
Underlying
motives for defining legal death as brain death need to be recognized as
required by the principle of intention, qa’idat al qasd, that states
that matters are to be considered according to their underlying intentions, al
umuur bi maqasidiha, and not the outward expression of objectives, al
‘ibrat fi al maqasid wa al ma’aani la al alfaadh wa al mabaani (Al Majallat
Article No 2 & No. 3). There was pressure to recognize brain death as the
earliest indication of death as a legal definition of death. The ethical
problem arising from this pressure was that the outward and expressed purpose
of using brain death criteria was divergent from the underlying motive. This
pressure arose from three sources: organ transplantation, artificial life
support, and research.
Organ
transplantation teams want to declare death early to harvest organs from heart
beating patients before organ deterioration due to increasing lack of oxygen
and nutrients[7],[8]
as well as accumulation of toxic metabolic waste. The motivation of the 1968
Harvard criteria for brain death could have been procuring organs for
transplantation[9]. Acceptance of brain death as legal death
enabled harvesting organs[10],
made it easy for health care workers to make decisions related to organ
donation[11],
and encouraged families to consent to donation if misconceptions were removed
about brain death.[12]
The
use of artificial life support systems deprived physicians of the use of
cardio-respiratory arrest as a sign of death, leaving only brain death as the
sole determinant. Physicians caring for terminal patients would like to
recognize death earlier so that they do not waste resources on patients who are
dying; this is an important ethical consideration even if the family or the
society were affluent and could afford such care.[13]
This partly explained the coincidence of
the adoption of the brain death criterion with advances in artificial
ventilation.[14],11
Researchers
especially those working on neural tissues would like to declare brain death
earlier so that they can obtain organs and tissues for research before they
deteriorate.[15]
Brain
Death Criteria
Brain
death criteria do not reach the level of absolute certainty, yaqiin, but
could be considered to be predominant conjecture, ghalabat al dhann, for
defining legal death. The first criteria were published in 1968 under the title
‘A Definition of Irreversible Coma’ in the Journal of the American Medical
Association by the Ad Hoc Committee of the Harvard Medical School. They defined
a permanently non-functioning whole brain (irreversible loss of function of the
whole brain). The criteria given for brain-death syndrome were: apneic coma
with no evidence of brain stem or spinal reflexes and a flat
electroencephalogram over a period of 24 hours. The report implied that death
was brain death and recommended withdrawal of life support. In 1973, brain stem
death was identified as the point of no return and the United States Uniform Determination
of Death Act was enacted permitting organ procurement from heart-beating donors. The Harvard
criteria were controversial from the start until our day raising the issue of
uncertainty because according to the principles of the Law doubt does not void
a certainty, al yaqiin la yazuulu bi al shakk (Majallat Article No 4). In
this case life is a certainty and brain death is a doubt.
Five
objections to the Harvard criteria were raised[16].
The first was that brain death was not followed by disruption of the integrity
and coordination of the living organism. The second was that the criteria of
brain death could not pinpoint the exact moment on the death time line when
death occurs. The third objection was
that brain death criteria for a person with a beating heart ignored
psychosocial, cultural, and religious aspects of death. The fourth objection was
that autopsy did not consistently validate the brain death criteria by findings
of irreversible brain stem ischemic injury or necrosis. The fifth objection was
that the criteria could not distinguish among various states on the spectrum
that that starts with coma through various states of loss of consciousness
(coma, akinetic mutism / locked-in syndrome, minimally conscious state,
vegetative state) and ends with brain death.
There
was consensus world-wide on the clinical signs of brain stem death but no such
consensus existed with regard to the criteria of brain death or the
confirmatory tests among different countries and among institutions in the same
country.11,[17]
Decisions based on professional consensus have the force of law according to
the principle that custom is a basis for legal rulings, al ‘aadat muhakkamat
(Al Majallat Article No 36). New knowledge and development of new technologies
result in frequent revisions of guidelines of brain death determination and
procedures at the local, national, and even international levels18,[18].
These changes are valid according to the principle that rulings can change with
time, la yunkar taghayyur al ahkaam bi taghayyur al azmaan (Al Majallat
Article No. 39).
Clinical
Determination of Brain Death
Clinical
signs of brain stem death enjoyed a wide consensus fulfilling the requirements
of the principle of custom, qa’idat al ‘aadat, that what is customary
has the force of law, al ‘aadat muhakkamat (al Majallat Article No. 36)
and also that what is customary is what is widespread and dominant, innama
yu’utabar al ‘aadat idha atradat aw ghalabat (Al Majallat Article No 41),
wide spread and not rare, al ‘ibrat li al ghaalib al shai’u la al naadir
(Al Majallat Article No 42). The uncertainty in clinical signs may arise from
deficient clinical experience of the examiner or presence of confounding
factors. In cases of uncertainty, extra confirmatory tests have to be
undertaken. Also normally the examination is repeated after an interval of time
to confirm the initial findings.
In
1995 The American Academy of Neurology published guidelines on determining
brain death based on coma, absent brainstem reflexes, and apnea, as well as the
exclusion of reversible confounders with ancillary tests being carried out in
case of uncertainty.[19]
The
first step was to exclude causes of reversible coma or unconsciousness that
could be confused with brain stem death. These included hypotension,
hypothermia, drugs that depress the nervous system, and metabolic disturbances[20].
Presence of drugs that depressed the central nervous system could be detected
using chromatographic methods[21],[22]
but their elimination could be delayed requiring monitoring[23].
The
second step was to identify a plausible cause of brain stem death. The clinical
signs could not be interpreted correctly in the absence of knowledge of a
possible cause of brain death. Knowledge of such a cause enabled elimination of
confounding causes of the signs such as intoxication, metabolic alterations,
major facial injury, infra-tentorial lesions, and cervical spinal cord injury[24].
The
third step was to elicit clinical signs of brain stem death: 1. Absence
of pupillary reflexes (constriction of pupils when light is shorn in them). 2.
Fixedly-dilated pupils. 3. Absence of the corneal reflex
(blinking when cornea is stimulated). 4. Absence of eye movements. 5. Absence
of the orbicularis oculi or blink reflex when eyes are illuminated by a strong
light[25].
6. Absence of the vestibule-ocular reflex which is absence of eye
movement when the external auditory meatus is flushed with 20 ml of ice cold
water, 7. Absence of motor response to stimulation in the area of
cranial nerve distribution such as absence of grimacing on applying firm
pressure above the eye socket. 8. The apnea test (lack of spontaneous
respiration on disconnecting the respirator). 8. Absence of cephalic
reflexes, 9. Absence of motor response to pain. 10. Absence of
the cough reflex and the gag reflex (coughing or gagging when a catheter is
passed down the airway).
The
apnea test was based on the absence of spontaneous respirations when carbon
dioxide accumulated to a level that should trigger respiration. The patient was
made to breathe oxygen and then the respirator was disconnected long enough for
carbon dioxide to accumulate in the lungs to trigger spontaneous breathing.
Rather than relying on elapsed time, a specific level of pCO2 could
be defined as the required stimulus for triggering breathing[26].
The apnea test was criticized because of low sensitivity and specificity, causation
of brain stem death due to increased intra cranial hypertension / baropressure
caused by hypercabia[27],
and other complications[28].
Confirmation
of brain death required a second examination after an interval that varied
according to institution. An argument in favor of early organ harvesting was
that the second examination was not necessary because empirical research showed
that none of those declared brainstem dead ever recovered and the wait for the
second examination was associated with loss of organs and more refusals of
organ harvesting[29].
Confirmatory
instrumental tests of brain death
The
primary diagnosis of brain death was based on clinical examination followed by
confirmatory instrumental tests that were of two kinds: measurement of brain
electrical activity and measurement of brain blood flow. These tests related to
whole brain death and were not specific for brain stem death. There were questions
about the diagnostic utility of these tests more and above those of clinical
tests. Using clinical criteria these tests might be false positive or false
negative. The tests indicated brain death when pathologic studies still found
viable brain tissue[30].
Laboratory
tests relied on chemical methods. One of these tests was measurement of oxygen
saturation in the cutaneous jugular bulb[31].
Neurophysiological
tests depended on measuring electrical activity of the brain. Electroencephalography
(EEG) [32]
was one of the earliest tests. It could be quantified as a range from
isoelectric=0 to fully awake=100[33].
Evoked potentials were measurements of electrical activity after sensory
stimulation for example the auditory brain-stem
responses (ABRs) and somatosensory evoked potentials (SEPs)[34].
Monitoring of brain stem evoked potentials over time in comatose patients was
more useful because their loss meant brain stem death[35].
The trend and not the cessation of the auditory evoked potential might be more
meaningful[36].
Imaging
techniques improved brain death diagnosis. Cerebral angiography was an invasive
investigation that showed cerebral circulatory arrest. Computed Tomographic
Angiography (CTA)[37],[38]
was a non-invasive examination that indicated cessation of blood circulation by
showing pooling of blood in cerebral blood vessels. Its reliability was
questioned when compared to EEG[39]
and it was observed to diverge from cerebral angiography[40].
Trans cranial Doppler was a cheap and
easy non-invasive bedside examination[41]
but its reliability varied with time from brain death[42]
and there were debates about its reliability[43].
Other techniques used were: cerebral perfusion scintillography[44],
single photon computed tomography[45],
and magnetic resonance imaging[46].
Discussions
The
major purpose of the law relevant to brain death is protection of life, maqsad
hifdh al nafs. It requires that death should not be declared in a living
person without evidence-based certainty because the declaration will be
followed by measures with irreversible consequences such as cessation of life
support, organ harvesting, and burial. Mistaken diagnosis has therefore very severe
consequences.
The
purpose of protecting resources, maqsad hifdh al mal, is fulfilled by earlier
determination of death using brain death criteria to stop expensive life
support in the intensive care unit. Costs related to long ICU hospitalization
are direct such as salaries and costs of equipment and supplies. There are
indirect costs to the family who have to leave their work and travel daily to
the hospital. Since the protection of life takes precedence over protection of
resources, death cannot be declared on the basis of expense of ICU care. It
should be evaluated on its own criteria. However once death is confirmed with
certainty any further ICU care is a waste of resources.
The
principle of intention, qa’idat al qasd, states that actions are judged
by their underlying motivation, al umuur bi maqasidiha. The quest to
define death as brain death has underlying motives that may not be in the best
interests of the patient but may be in the interests of others. In ancient
times there was no pressure to recognize the earliest point in time at which
death occurred. In modern times there is pressure to recognize death earlier to
enable organ harvesting. While the ultimate objective is noble, we should not
violate the principle that the ends do not justify the means, al wasail laha
hukm al maqasid[47].The determination of
death should ethically be independent of other considerations like organ
harvesting, cost control, or research.
Organ
harvesting was recognized as a major motivator for early brain death diagnosis
so that organs can be harvested before deterioration. Some observations cast
doubt on this assumption. Doubts were expressed about organ deterioration for
patients in the ICU[48]
and in any case active donor resuscitation could prevent or minimize the
deterioration[49].
The
underlying motivations for adopting brain death criteria had benefits for
individuals who are recipients of organs. They might have benefits for families
who are saved paying extra expenses in ICU care. They might also have public
interests in saving health care resources or advance of medical knowledge. Therefore
rare errors in declaring death in an individual could be mitigated by
consideration of the public interest of protecting the lives of many organ
recipients by use of brain death criteria. This is justified by the principle
that individual harm could be sustained to prevent public harm, yutahammal
al dharar al khaas li daf’e dharar ‘aam (Al Majallat Article No. 26). Even
in this situation we still have to face an ethical issue of deception because
outwardly death is declared on the basis of brain death criteria but there is
an unstated motive of seeking organs for transplantation. If the motivation for declaring brain death
is under pressure from a known specific organ recipient we may have a major
ethical problem because of causing potential harm to a donor to benefit a
recipient which would violate the principle that prevention of harm has
precedence over getting a benefit, dariu al mafasid awla min jalbi al
masaalih (Al Majallat Article No 30).
The
principle of certainty, qa’idat al yaqiin, requires that recognition of
death be based on clear evidence. The evidence is facts that can be established
by empirical observation. Interpretation
of the evidence to reach conclusions about the occurrence of death requires
consideration of the evidence according to consensus criteria. There are
problems about reaching consensus on the criteria.
The
Harvard death criteria generated controversy since they were first formulated.
The objection that brain death did not lead to disintegration of the body was
difficult to test in practice because normally patients were put on artificial
life support and there was no need for bran coordination of vital functions.
When the support was withdrawn the patient succumbed inevitably to death but at
varying intervals depending on the extent of the brain damage. The inability of
the criteria to pinpoint the exact moment on the death was conceptually valid
but was not relevant practically in an irreversible death trajectory. The
objection that the criteria ignored non-medical aspects was a valid criticism
of modern medical practice that is based on the biomedical model and
marginalizes psychosocial and religio-cultural aspects. The marginalized
aspects were virtually impossible to operationalize but were taken care of when
the consent of the family is sought in decisions about organ donation and
withdrawal of life support. The fact that autopsy findings did not always
validate the criteria raised serious issues about the certainty of brain stem
death but a mitigating factor was that in the experience of virtually all
clinicians no patient properly diagnosed as brain stem dead has ever returned
to normal life. The criteria were unable to distinguish among various states on
the spectrum that that started with coma through various states of loss of
consciousness (coma, akinetic mutism / locked-in syndrome, minimally conscious
state, and vegetative state) and ended with brain death. The problem was that one of these states can be
confused for brain death.
A
sixth objection that could be added is that the Harvard criteria envisaged
whole brain death and did not distinguish between cerebral cortex (higher brain
death) and brain stem death. Cerebral death meant cessation of higher
intellectual functions with preservation of vital cardio-respiratory function
in what is called a vegetative state. The brain stem contained the vital
respiratory and circulatory centers and its death was recognized as definitive
death by a consensus of many jurists. Brain stem death was easy to diagnose
clinically but difficult to confirm using instrumental confirmatory tests that
depended on whole-brain function.
According
to the principle of custom, a professional consensus on criteria of death and
determination of death is legally binding, al ‘aadat muhakkamat
(Majallat Article No. 36). The condition is that this consensus be by a
preponderant majority of the professionals and not by a minority. It also must
have stood the test of time. In the situation of brain death the consensus on
clinical signs of brain stem death seems universal but the same consensus is
not found for confirmatory instrumental tests. This means that clinical tests
will remain a main stay of diagnosing brain stem death.
A
sub principle of the principle of custom, that legal rulings change with time, la
yunkir taghayyur al ahkaam bi taghayyur al azmaan (Majallat Article No 39),
is the basis for the legal validity of changing definitions of death with
developments in medical knowledge and technology. The definition and criteria
of death change with new knowledge and new technological capabilities. They also change according to underlying
motivations such the need to declare legal death early in order to save
artificial life support resources or to harvest organs for transplantation.
This sub principle allows for change of consensus without condemning as wrong
previous consensus.
We
may speculate that it is possible that death of the brain as measured using
available technology today misses out on other unknown functions of the brain
that may continue after its ‘perceived’ physical death.
Conclusions
The
criteria and determination of brain death do not fully conform to principles of
intention, certainty, and custom. Considerations of organ harvesting, ICU costs
and research have been a driving force behind development of brain death
criteria. These criteria have been changing with development of knowledge and
technology and have not reached the level of universal consensus having
variation by country and by institution. There is consensus about the
reliability of clinical tests of brain stem death but there is no such
consensus on the reliability of the instrumental confirmatory tests.
Recommendations
Brain
stem death should remain the mainstay of death definition notwithstanding the
uncertainties that have been discussed above because the public interest
inherent in organ harvesting and saving ICU resources overcomes these concerns.
Legal rulings, fatwa, on brain death should be reviewed every 3 years to take
into consideration new developments in medical knowledge and technology.
REFERENCES
Available upon request