Brain death -Dr. Cohen

8/7/2019 Brain death -Dr. Cohen

1/42

Brain DeathBrain Death

Anatomy and PhysiologyAnatomy and Physiology

Joel S. Cohen, M.D.Joel S. Cohen, M.D.Associate Professor of Clinical NeurologyAssociate Professor of Clinical Neurology

Albert Einstein College of MedicineAlbert Einstein College of Medicine


2/42

Historical PerspectiveHistorical Perspective

Prior to the advent of mechanicalPrior to the advent of mechanicalrespiration, death was defined as therespiration, death was defined as thecessation of circulation and breathingcessation of circulation and breathing


3/42

Historical PerspectiveHistorical Perspective

19591959 Coma depasseComa depasse Mollaret and GoulonMollaret and Goulon

19681968 Irreversible Coma/Brain DeathIrreversible Coma/Brain Death Harvard MedicalHarvard MedicalSchool Ad Hoc CommitteeSchool Ad Hoc Committee

1981 Uniform Determination of Death Act1981 Uniform Determination of Death Act -- PresidentsPresidentsCommission for the Study of Ethical Problems in MedicineCommission for the Study of Ethical Problems in Medicine

1994 American Academy of Neurology Guidelines for the1994 American Academy of Neurology Guidelines for thedetermination of Brain Deathdetermination of Brain Death

2005 NYS Guidelines for Determining Brain Death2005 NYS Guidelines for Determining Brain Death


4/42

Brain Death Current ConsensusBrain Death Current Consensus

Absent Cerebral FunctionAbsent Cerebral Function

Absent Brainstem FunctionAbsent Brainstem Function

ApneaApnea


5/42

Normal Brain AnatomyNormal Brain Anatomy


6/42

Normal Brain AnatomyNormal Brain Anatomy

Cerebral Cortex

Brain Stem

Reticular

Activating

System


7/42

Cerebral CortexCerebral Cortex

CognitionCognition

Voluntary MovementVoluntary Movement

SensationSensation


8/42

Brain StemBrain Stem


9/42


MidbrainCranial Nerve III

pupillary function

eye movement


10/42


Pons

Cranial Nerves IV, V, VI

conjugate eye movement

corneal reflex


11/42


MedullaCranial Nerves IX, X

Pharyngeal (Gag) Reflex

Tracheal (Cough) Reflex

Respiration


12/42

eticular ActivatingReticular Activating

SystemSystem

Receives multipleReceives multiplesensory inputssensory inputs

MediatesMediateswakefulnesswakefulness


13/42

Causes of Brain DeathCauses of Brain Death

Normal Cerebral Anoxia


14/42


Normal Cerebral Hemorrhage


15/42


Normal Subarachnoid Hemorrhage


16/42


Normal Trauma


17/42


Normal Meningitis


18/42

Mechanism of Cerebral DeathMechanism of Cerebral Death

Neuronal Injury

Decreased IntracranialBlood Flow

Neuronal Swelling

Increased IntracranialPressure

ICP>MAP isincompatible

with life


19/42

Conditions Distinct FromConditions Distinct From

Brain DeathBrain Death

Persistent Vegetative StatePersistent Vegetative State

LockedLocked--in Syndromein Syndrome

Minimally Responsive StateMinimally Responsive State


20/42

Persistent Vegetative StatePersistent Vegetative State

Normal SleepNormal Sleep--Wake CyclesWake Cycles

No Response to Environmental StimuliNo Response to Environmental Stimuli

Diffuse Brain Injury with PreservationDiffuse Brain Injury with Preservationof Brain Stem Functionof Brain Stem Function


21/42

LockedLocked--in Syndromein Syndrome

Ventral Pontine Infarct

Complete Paralysis

Preserved Consciousness

Preserved Eye Movement


22/42

Minimally Responsive StateMinimally Responsive State

Diffuse or MultiDiffuse or Multi--Focal Brain InjuryFocal Brain Injury

Preserved Brain Stem FunctionPreserved Brain Stem Function

Variable Interaction withVariable Interaction withEnvironmental StimuliEnvironmental Stimuli

Static Encephalopathy


23/42

Brain Death NeurologicalBrain Death Neurological

ExaminationExaminationClinical Prerequisites:Clinical Prerequisites:

Known Irreversible CauseKnown Irreversible Cause

Exclusion of Potentially Reversible ConditionsExclusion of Potentially Reversible Conditions Drug Intoxication or PoisoningDrug Intoxication or Poisoning

Electrolyte or AcidElectrolyte or Acid--Base ImbalanceBase Imbalance

Endocrine DisturbancesEndocrine Disturbances

Core Body temperature > 32Core Body temperature > 32 CC


24/42

Brain Death NeurologicalBrain Death Neurological

ExaminationExamination

ComaComa

Absent Brain Stem ReflexesAbsent Brain Stem Reflexes

ApneaApnea


25/42

ComaComa

No Response to Noxious StimuliNo Response to Noxious Stimuli

Nail Bed PressureNail Bed Pressure

Sternal RubSternal Rub

SupraSupra--Orbital Ridge PressureOrbital Ridge Pressure


26/42

Absence of Brain StemAbsence of Brain Stem

ReflexesReflexes Pupillary ReflexPupillary Reflex

Eye MovementsEye Movements

Facial Sensation and Motor ResponseFacial Sensation and Motor Response

Pharyngeal (Gag) ReflexPharyngeal (Gag) Reflex

Tracheal (Cough) ReflexTracheal (Cough) Reflex


27/42

Pupillary ReflexPupillary Reflex

Pupils dilated with no constriction to bright light


28/42


Occulo-Cephalic Response

Dolls Eyes Maneuver


29/42


Oculo-Vestibular Response

Cold Caloric Testing


30/42

Facial Sensation andFacial Sensation and

Motor ResponseMotor Response Corneal ReflexCorneal Reflex

Jaw ReflexJaw Reflex

Grimace to Supraorbital orGrimace to Supraorbital or

TemporoTemporo--Mandibular PressureMandibular Pressure


31/42

Apnea TestingApnea Testing

PrerequisitesPrerequisites

Core Body Temperature > 32Core Body Temperature > 32 CC

Systolic Blood Pressure 90 mm HgSystolic Blood Pressure 90 mm Hg

Normal ElectrolytesNormal Electrolytes

Normal PCO2Normal PCO2


32/42

Apnea TestingApnea Testing

1. Pre1. Pre--OxygenationOxygenation

100% Oxygen via Tracheal Cannula100% Oxygen via Tracheal Cannula

PO2 = 200 mm HgPO2 = 200 mm Hg

2. Monitor PCO2 and PO2 with pulse oximetry2. Monitor PCO2 and PO2 with pulse oximetry

3. Disconnect Ventilator3. Disconnect Ventilator

4. Observe for Respiratory Movement until PCO2 =4. Observe for Respiratory Movement until PCO2 =60 mm Hg60 mm Hg

5. Discontinue Testing if BP < 90, PO2 saturation5. Discontinue Testing if BP < 90, PO2 saturationdecreases, or cardiac dysrhythmia observeddecreases, or cardiac dysrhythmia observed


33/42

Confounding ClinicalConfounding Clinical

ConditionsConditions Facial TraumaFacial Trauma

Pupillary AbnormalitiesPupillary Abnormalities

CNS Sedatives or Neuromuscular BlockersCNS Sedatives or Neuromuscular Blockers

Hepatic FailureHepatic Failure

Pulmonary DiseasePulmonary Disease


34/42

Observations CompatibleObservations Compatible

with Brain Deathwith Brain Death Sweating, BlushingSweating, Blushing

Deep Tendon ReflexesDeep Tendon Reflexes

Spontaneous Spinal ReflexesSpontaneous Spinal Reflexes-- Triple FlexionTriple Flexion

Babinski SignBabinski Sign


35/42

Confirmatory TestingConfirmatory Testing

Recommended when the proximateRecommended when the proximatecause of coma is not known or whencause of coma is not known or whenconfounding clinical conditions limitconfounding clinical conditions limitthe clinical examinationthe clinical examination


36/42


EEG

Normal Electrocerebral Silence


37/42


Cerebral AngiographyCerebral Angiography

Normal No Intracranial Flow


38/42


TechnetiumTechnetium--99 Isotope Brain Scan99 Isotope Brain Scan


39/42


MRMR-- AngiographyAngiography


40/42


Transcranial Ultrasonography


41/42


Somatosensory Evoked PotentialsSomatosensory Evoked Potentials


42/42

Concern for man and his fate mustConcern for man and his fate must

always form the chief interest of allalways form the chief interest of all

technical endeavors. Never forgettechnical endeavors. Never forgetthis in the midst of your diagramsthis in the midst of your diagrams

and equations.and equations.

Albert EinsteinAlbert Einstein

Brain death -Dr. Cohen

Documents