technical assistance for alignment in organ donation- europeaid/131052/d/ser/tr key points in brain...
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Technical Assistance for Alignment in Organ Donation- EuropeAid/131052/D/SER/TR
Key Points in Brain Death Diagnosis
Clinical aspects and Confirmation
Francesco Procaccio
ISS – CNT - Rome
Neuro Intensive Care Unit
University City Hospital, Verona - Italy
Total Brain Infarct
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What is Brain Death?
Brain Death is the irreversible loss of capacity for consciousness combined
with the irreversible loss of all brainstem functions including the
capacity to breathe.
The Canadian Neurocritical Care Group, 1999
BD Definition
F Procaccio 2012
Certainty of death: Irreversibility
Karnice-Karnicki, 1896
Brain Death or Brain Dying?
Death is a process
Neurological functions must have ceased
irreversibly
“Irreversible loss of all cerebral functions”
(Brain) Death
Brainstemdeath
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WhyBrain death is the only
death ?
Pathophysiological reasons
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When a person is dead?Definitive, irreversible total damage of the
brainCerebral functions are totally lost
Due to two different mechanisms:
1) Respiratory and circulatory arrest causing secondary irreversible damage of brain (non Heart Beating cadaver)
2) Devastating cerebral lesions which cause total irreversible damage of the brain (Brain Death – Heart Beating cadaver)
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Definition of death (Universal death)
Capron , May 2012 Montreal Forum
Simple uniform reliable concepts & definitions
may increase public confidence and trust
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Heart, Lung, Liver, Kidneys etc.are vital organs
butcan be supported by technology or replaced by transplantation.
except The Brain
Whyonly Brain death is death ?
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Who may become brain dead ?
Only patients with acute cerebral lesion under
mechanical ventilation in ICU
Brain injury – Cerebral Hemorrhage Ischemic Stroke – Brain Tumour Anoxia – Cerebral Infection etc.
Determination of deathby neurological criteria
“All the cerebral functions are irreversibly lost”
Clinical
REFLEXES
EEG
Determination of Death by Neurological criteria
CBF
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Total Brain InfarctAbsence of cerebral blood flow
Death
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Harvard Criteria - 1968
The Neurological Standard
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Wijdicks E. N Engl J Med 2001
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Brain Death Diagnosis Milestones
1. The etiology of the brain lesion is known
2. Exclude all potential confounding factors
3. The neurological examination is complete and all clinical criteria are fulfilled
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Etiology
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NMR
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Clinical examination
Prerequisites
• Etiology must be known• Imaging of irreversible cerebral
damage• Temp. >32 °C (“Normal” BP – SO2 – Na+)
• Exclusion of medical confounding factors
• Exclusion of drug effects on CNS• Exclusion of drug effects on clinical
exam (muscle relaxant agents, atropine etc.)
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The Brainstem
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II
III
V
VI VII
VIII
X
XI
Light response
Corneal
Oculocephalic
Oculovestibular
Brainstem reflexes:pathways
Painful stimuli
Tracheal
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Pupillary response to lightMethodology & clinical experience
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APNEA TEST
Absence of respiratory drive130
98130 78 23
PaCO2 > 60mmHg
100% Oxygen
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Why brain dead patients may move ?
Spinal reflexes in Brain Death
Brain infarct
Spine without superior control
SpinalShock
Spinal function recovery
Hyperexcitability
1
2
3
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Are there factors that may cause unreliable brain death
diagnosis?
CONFOUNDING FACTORS
Severe derangement in temperature, blood pressure, oxygenation,
electrolytes, glusose, cortisol, T4)
Drugs (sedative/anesthetic - barbiturates ! – muscle relaxants )
Facial trauma – Cranial nerves lesions31
Facial Trauma
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If potentially confounding factors
may be present confirmatory tests
must be used
The absence of cerebral perfusion is a simple,
clear, acceptable criteria, easily to be
understood and demonstrated.
Cerebral angiogram. Arch injection
Wijdicks, 200135
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TCD
Brain Deathpatterns
Trans Cranial Doppler
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F Procaccio 2012
Girlanda
R
Angio-CT scan
BD standard – no confounding factors
Persistence of cerebral blood “flow” after brain death
Flowers WM et al. Southern Medical Journal 93:364,2000
• Decompressing fractures• Ventricular shunts• Reperfusion (post-anoxic !)• Decompressive Hemicraniectomy
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F Procaccio 2012
Possible Pitfalls in BD diagnosis
1. the BD declared patient is not Dead
zero mistake must be ensured
2. the BD person is not BD declared
silent BD – Death is not equal - missing PODs
Mimicking Disorders
• Hypothermia• Barbiturates• Acute poisoning• Endocrine crisis
(glucose – cortisol – T4)
• neurological diseases
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“Neurological” conditions that may be confused with Brain
Death
• Locked-in syndrome• Guillain-Barré syndrome• Demyelinating conditions • Post-anoxic coma• Brainstem encephalitis• “Medulla man”
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The Medulla Man
Wijdicks E. J Neurol Neurosurg Psych 200143
F Procaccio 2012
Post-anoxic BD
Neuro ICU, Verona - 2005
swelling “flow”6 hours
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F Procaccio 2012
Possible Pitfalls in BD diagnosis
1. the BD declared patient is not Dead
zero mistake must be ensured
2. the BD person is not BD declared
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Brain Death Declaration
Certain diagnosis
plus
Legal procedures
Clinical Diagnosis simple and reliable
Must be complete
methodicalrigorous
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Deceased Organ Donation Dead Donor Rule
Death determination (diagnosis)
• Threshold of irreversibility• Clinical standard• Confirmatory tests
Dying process
(legal) Death declaration• Adherence to guidelines• Legal procedures • The moment of Death
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Brain death diagnosis (clinical criteria)
etiology
ComaBrainstemreflexes
+apnea
MandatoryEEG
MandatoryCBF
CBFIn
DefinedConditions
children
All pts or only potential donors?
other
x x x no x x all>24hrs anoxic
BD declaration (legal procedures)
Observationperiod
N° MD
Repeated clincial tests
RepeatedEEG
Repeated CBF Children
All ptsOr only
Potential Donors?
6 hrs 3 2 2 no x all Italy
Law –Decree ? !x!National Guidelines ? !x! Country: Italy
Death determination by neurological criteria
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ICU Admission
VegetativeStorm
(coning)
Brain DeathDeclaration
1 2 3 4
Patient treatment
Timing in Death declaration
BDcriteria observation
Death
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Common Principles for present/future ?
Citizens equal in death: Death declaration independent from organ donation
Clear, simple and acceptable definitions, criteria and procedures in death diagnosis
A «Universal death» independent from clinical and (new) technical aspects
Clear legal procedures for death declaration
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1. Treating physicians (Intensivists!) should be more involved in BD diagnosis and potential donor identification.
2. BD Pathophysiology based guidelines should guide BD diagnosis and donor treatment.
3. Law and decrees should have (few) technical details aimed to BD (legal) declaration
Suggestions
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1. Specific education and common language are needed.
2. Quality of critical care may facilitate BD diagnosis.
3. The probability of success in organ donation reflects the capacity of declaring brain death in all the patients fulfilling BD criteria.
Key factors
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Case study
Reversible Brain Death
A 55-yr-old man presented with cardiac arrest preceded by respiratory arrest.
Cardiopulmonary resuscitation was performed, spontaneous perfusion restored, and therapeutic hypothermia was attempted for neural protection.
After rewarming to 36.5°C, neurologic examination showed no eye opening or response to pain, spontaneous myoclonic movements, sluggishly reactive pupils, absent corneal reflexes, and intact gag and spontaneous respirations.
Day 1Facial Myoclonus
Over 24 hours, remaining cranial nerve function was lost.
The neurologic examination was consistent with brain death.
Apnea test and repeat clinical examination after a duration of 6 hrs confirmed brain death.
Death was pronounced and the family consented to organ donation.
Are there factors that may cause unreliable brain death
diagnosis?
Twenty-four hrs after brain death pronouncement, on arrival to the operating room for organ procurement, the patient was found to have regained corneal reflexes, cough reflex, and spontaneous respirations.
The care team faced the challenge of offering an adequate explanation to the patient's family and other healthcare professionals involved.
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Would you consider propofol/fentanyl a potential confounding factor at hour 80 ?
1) Yes2) No3) maybe
The ideal practice is to use confirmatory tests
only if necessary
to confirm the clinical examination.
Physicians should not go far as to place blind faith in machinery and
the clinical diagnosis remains a sacrosant principle.
EFM Wijdicks, 2001
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Is an ancillary test
1) Useful
2) Mandatory
3) Unreliable
F Procaccio 2012
SEPs NMR CBF CCA
170
195 200 202
venti
latio
nw
ithdr
awal
Ope
ratin
g ro
om
1°- 2
° clin
ical
exa
m +
apn
ea te
st
HypothermiaSedation
Although the reversal was transient and did not impact the patient's prognosis, it impacted his eligibility for organ donation and cast doubt about the ability to determine irreversibility of brain death findings in patients treated with hypothermia after cardiac arrest.
CONCLUSIONS:
We strongly recommend caution in the determination of brain death after cardiac arrest when induced hypothermia is used. Confirmatory testing should be considered and a minimum observation period after rewarming before brain death testing ensues should be established.