A comprehensive discussion of death and the criteria required to assert it.What is clinical death and the conditions needed to diagnose it

1. CRITERIA
OF
BRAIN DEATH
WALID S. MAANI
PROFESSOR AND CHAIRMAN OF
NEUROSUERGERY

2. DEFINITION
Brain death is defined as a complete and
irreversible cessation of brain activity.
Absence of apparent brain function is not
enough.
Evidence of irreversibility is also required.
Brain-death is often confused with the state
of vegetation

3. HISTORICAL NOTES
 In 1564, Versalius a famous anatomist is said to
have conducted an autopsy in Madrid on a
nobleman who had been his patient . This
autopsy was carried out in front of a large crowd
of citizens and when the thorax of the body was
opened the heart was beating. After that
Versalius was compelled to leave Spain. This
and others episodes probably have made it
necessary to have physicians pronounce the
death of patients

4. HISTORICAL NOTES
 Traditionally, death has been defined as the cessation of
all body functions, including respiration and heartbeat.
 Since it became possible to revive some people after a
period without respiration, heartbeat, or other visible
signs of life, as well as to maintain respiration and
blood flow artificially using life support treatments, an
alternative definition for death was needed.
 In recent decades, the concept of "brain death" has
emerged. By brain-death criteria, a person can be
pronounced legally dead even if the heart continues to
beat due to life support measures. The first nation in the
world to adopt the brain death as the definition of legal
death was Finland in 1971.

5.  A brain-dead individual has no
electrical activity and no clinical evidence
of brain function on physical examination
(no response to pain, absent cranial nerve
reflexes (pupillary response (fixed pupils),
oculocephalic reflex, corneal reflexes),
absent response to the caloric reflex test
and no spontaneous respirations).

6.  It is important to distinguish between brain
death and states that mimic brain death
(e.g. barbiturate intoxication, alcohol
intoxication, sedative overdose,
hypothermia, hypoglycemia, coma or
chronic vegetative states).

7.  The concept that death can be defined as
the irreversible cessation of brain
functions is universally recognized in the
world through statutes, judicial decisions,
or regulations.
 In 1985 in Amman an Arab conference on
the subject adopted the universal criteria
for the concept.

8.  A physician who makes a determination of
death in accordance with these criteria
and accepted medical standards is not
liable for damages in any civil action or
subject to prosecution in any criminal
proceeding for his acts or the acts of
others based on that determination .

9.  Most published guidelines for determining
brain death have relied on the findings of
prospective clinical studies
 Report of the Ad Hoc Committee of the
Harvard Medical School to Examine the
Definition of Brain Death
 Collaborative Study of the National Institutes
of Neurological Diseases and Stroke

10.  These studies indicate that a patient will
not survive with irreversible coma, apnea,
absence of brain stem reflexes, and an
isoelectric electroencephalogram (EEG)
that persists for 6 hours after the onset of
coma and apnea.

11.  Following the published guidelines assures that
a patient who is still alive will not be
misdiagnosed as dead.
 The patient in coma with some remaining brain-
related bodily functions is not dead.
 Either behavioral responses or brain stem reflexes
indicate that brain death has not occurred.
 A patient in a chronic vegetative state may remain in
a prolonged coma indefinitely, yet not meet the
criteria for brain death.
 For children less than 1 year of age, special
assessments may be necessary.

12. CLINICAL ASSESSMENT
 TWO physicians should be involved:
 A neurologist or neurosurgeon
 An intensive care specialist
 The treating physician SHOULD NOT BE
INCLUDED.

13.  The clinical guidelines for this assessment
are the following:
1. Absence of Cerebral Function
2. Absence of Brain Stem Function

14.  Absence of Cerebral Function
 Essential to the diagnosis of brain death is
that the cause of coma be known.
 Patients must be in a deep coma without any
response to verbal or painful stimuli.
 All reversible causes of coma must be ruled
out including hypothermia (core body
temperature less than 33° C), drug
intoxication, hypotension, neuromuscular
blockade, and sedating medicines.

15.  Absence of Cerebral Function
 Confirmatory tests must be performed and
may include:
 EEG
 Cerebral angiography
 Isotope angiography
 An isoelectric EEG is mandatory.
 EEG could not be used as the sole test
because it is influenced by hypothermia and
drugs.

16. SILENT EEG

17.  Absence of Brain Stem Function
 Clinical tests must also confirm the absence
of all brain stem reflexes including:
 Pupillary size and reactivity, and
 Corneal, oculo-vestibular
 Gag, and cough reflexes
 An apnea test must demonstrate an absence
of all spontaneous respiratory drive.

18.  It is recommended that physicians familiar with
the performance of this test be consulted when
appropriate.
 There must be apnea long enough for the
PaCO2 to become greater than 60 mm Hg in the
absence of metabolic alkalosis.
 The test of absent breathing should be
performed following hyperoxygenation on 100%
oxygen on mechanical ventilation.
 Adequate circulation should be maintained
during the entire apnea test.

19. Pupillary Signs
 Round, oval, or irregularly shaped pupils are compatible
with brain death, and most pupils are midsize (4-6 mm).
 The pupillary light reflex must be absent in brain death.
Although many drugs can influence pupillary size, the
pupillary light reflex remains intact only in the absence of
brain death.
 Standard doses of atropine administered intravenously
do not markedly affect pupillary response; similarly,
neuromuscular blocking agents do not markedly
influence pupillary size. However, topical administration
of drugs and ocular trauma may influence pupillary size
and reactivity.
 Preexisting ocular anatomic abnormalities may also
confound pupillary assessment in brain death.

20. Ocular Movements
Both oculocephalic “doll’s eye”; and vestibulo-ocular “caloric test”
reflexes are absent in brain death. Contraindications to testing for
oculocephalic reflexes include suspected fracture or instability of the
cervical spine. Likewise, contraindications to testing of vestibulo-
ocular reflexes include impaired integrity of tympanic membranes
 The oculocephalic reflex is elicited by rapidly and vigorously turning the
head to 90° laterally on both sides. The normal response is deviation of
the eyes to the opposite side of head turning. In brain death,
oculocephalic reflexes are absent, and no eye movements occur in
response to head movements.
 The vestibulo-ocular reflex is elicited by elevating the head 30° and
irrigating both tympanic membranes with 50 mL of iced saline or water.
In brain death, vestibulo-ocular reflexes are absent, and no deviatio n of
the eyes occurs in response to ear irrigations

21. DOLL’S HEAD EYE MOVEMENT
CALORIC TEST
Determining Brain Death Jacqueline Sullivan, Debbie L. Seem, and Franki Chabalewski, Critical Care Nurse , Vol 19, No.*
, 2, pp 37-46, 1999