Brain DeathBrain Death

Jana Stockwell, MDJana Stockwell, MD

Definition Definition

Cardiac death:Cardiac death:Heartbeat and breathing stopHeartbeat and breathing stop

Brain death:Brain death: Irreversible cessation of all functions of the Irreversible cessation of all functions of the

entire brain, including the brain stem entire brain, including the brain stem

HistoryHistory First introduced in a 1968 report authored by a special First introduced in a 1968 report authored by a special

committee of the Harvard Medical Schoolcommittee of the Harvard Medical School Adopted in 1980, with modifications, by the Adopted in 1980, with modifications, by the President's President's

Commission for the Study of Ethical Problems in Commission for the Study of Ethical Problems in Medicine and Biomedical ResearchMedicine and Biomedical Research, as a , as a recommendation for state legislatures and courtsrecommendation for state legislatures and courts

The "brain death" standard was also employed in the The "brain death" standard was also employed in the model legislation known as the model legislation known as the Uniform Determination of Uniform Determination of Death ActDeath Act, which has been enacted by a large number of , which has been enacted by a large number of jurisdictions and the standard has been endorsed by the jurisdictions and the standard has been endorsed by the influential American Bar Association. influential American Bar Association.

Anatomy of human brain – Anatomy of human brain – 3 regions3 regions

CerebrumCerebrum Controls memory, consciousness, and higher mental Controls memory, consciousness, and higher mental

functioningfunctioning

CerebellumCerebellum Controls various muscle functionsControls various muscle functions

Brain stem consisting of the midbrain, pons, and Brain stem consisting of the midbrain, pons, and medulla, which extends downwards to become medulla, which extends downwards to become the spinal cordthe spinal cord Controls respiration and various basic reflexes (e.g., Controls respiration and various basic reflexes (e.g.,

swallow and gag)swallow and gag)

ComaComa

Deep comaDeep comaNon-responsive to most external stimuliNon-responsive to most external stimuliAt most, such patients may have a dysfunctional At most, such patients may have a dysfunctional

cerebrum but, by virtue of the brain stem remaining cerebrum but, by virtue of the brain stem remaining intact, are capable of spontaneous breathing and intact, are capable of spontaneous breathing and heartbeatheartbeat

PVS – persistent vegetative statePVS – persistent vegetative state

Relationship of organ functionRelationship of organ function HeartHeart

Needs ONeeds O22 to survive and w/o O to survive and w/o O22 will stop beating will stop beating NotNot controlled by the brain but it is autonomous controlled by the brain but it is autonomous

BreathingBreathing Controlled by vagus nerve, located in the brain stemControlled by vagus nerve, located in the brain stem Main stimulant for vagus nerve is Main stimulant for vagus nerve is CO CO22 in the blood in the blood

Causes the diaphragm & chest muscles to expandCauses the diaphragm & chest muscles to expand Spontaneous breathing can not occur after brain stem deathSpontaneous breathing can not occur after brain stem death

With artificial ventilation, the heart may continue to With artificial ventilation, the heart may continue to beat for a period of time after brain stem deathbeat for a period of time after brain stem death

Time lag between brain death and circulatory death Time lag between brain death and circulatory death is ~2-10 days (case report - woman's heart beat for is ~2-10 days (case report - woman's heart beat for 63 days after a dx of brain death)63 days after a dx of brain death)

Initial requirementsInitial requirements

1.1. Clinical or radiographic evidence of an Clinical or radiographic evidence of an acute catastrophic cerebral event acute catastrophic cerebral event consistent w/ dx of brain deathconsistent w/ dx of brain death

2.2. Exclusion of conditions that confound Exclusion of conditions that confound clinical evidence (i.e.-metabolic)clinical evidence (i.e.-metabolic)

3.3. Confirmation of absence of drug Confirmation of absence of drug intoxication or poisoningintoxication or poisoning

Also barbiturates, NMB’sAlso barbiturates, NMB’s

4.4. Core body temp >32Core body temp >32ooC (we use 34C (we use 34ooC)C)

Basic exam 1Basic exam 1PainPain

Cerebral motor response to painCerebral motor response to painSupra-orbital ridge, the nail beds, trapeziusSupra-orbital ridge, the nail beds, trapeziusMotor responses may occur spontaneously Motor responses may occur spontaneously

during apnea testing (spinal reflexes)during apnea testing (spinal reflexes)Spinal reflex responses occur more often in Spinal reflex responses occur more often in

youngyoung If pt had NMB, then test w/ train-of-fourIf pt had NMB, then test w/ train-of-four

Spinal arcs are intact!Spinal arcs are intact!

Basic exam 2Basic exam 2PupilsPupils

Round, oval, or irregularly shaped Round, oval, or irregularly shaped Midsize (4-6 mm), but may be totally dilatedMidsize (4-6 mm), but may be totally dilated Absent pupillary light reflexAbsent pupillary light reflex

Although drugs can influence pupillary size, the light Although drugs can influence pupillary size, the light reflex remains intact reflex remains intact onlyonly in the absence of brain death in the absence of brain death

IV atropine does not markedly affect responseIV atropine does not markedly affect response Paralytics do not affect pupillary sizeParalytics do not affect pupillary size Topical administration of drugs and eye trauma Topical administration of drugs and eye trauma maymay

influence pupillary size and reactivityinfluence pupillary size and reactivity Pre-existing ocular anatomic abnormalities may also Pre-existing ocular anatomic abnormalities may also

confound pupillary assessment in brain deathconfound pupillary assessment in brain death

Basic exam 3Basic exam 3Eye movementEye movement

Oculocephalic reflex = doll’s eyesOculocephalic reflex = doll’s eyesVestibulo-ocular = cold caloric test Vestibulo-ocular = cold caloric test

Doll’s eyesDoll’s eyes

Oculocephalic reflexOculocephalic reflexRapidly turn the head 90° on both sidesRapidly turn the head 90° on both sidesNormal response = deviation of the eyes to Normal response = deviation of the eyes to

the opposite side of head turningthe opposite side of head turningBrain death = oculocephalic reflexes are Brain death = oculocephalic reflexes are

absent (no Doll’s eyes) = no eye movement in absent (no Doll’s eyes) = no eye movement in response to head movementresponse to head movement

Not Barbie, but old fashioned type dollsNot Barbie, but old fashioned type dollsPainted vs. wooden eyes in porcelain headsPainted vs. wooden eyes in porcelain heads

Doll’s eyesDoll’s eyes

Cold caloricsCold calorics

Elevate the HOB 30°Elevate the HOB 30° Irrigate both tympanic membranes with Irrigate both tympanic membranes with

iced watericed waterObserve pt for 1 minute after each ear Observe pt for 1 minute after each ear

irrigation, with a 5 minute wait between testing irrigation, with a 5 minute wait between testing of each earof each ear

Facial trauma involving the auditory canal and Facial trauma involving the auditory canal and petrous bone can also inhibit these reflexes petrous bone can also inhibit these reflexes

Cold calorics interpretationCold calorics interpretation

NystagmusNystagmus both eyes slow toward cold, fast to both eyes slow toward cold, fast to midline midline Not comatose Not comatose

Both eyes tonically deviate toward cold water Both eyes tonically deviate toward cold water ComaComa with intact brainstem with intact brainstem

Movement only of eye on side of stimulus Movement only of eye on side of stimulus Internuclear ophthalmoplegia Internuclear ophthalmoplegia Suggests brainstem structural lesionSuggests brainstem structural lesion

No eye movement No eye movement Brainstem injury / deathBrainstem injury / death

Basic exam 4Basic exam 4Facial sensory & motor responsesFacial sensory & motor responses

Corneal reflexes are absent in brain deathCorneal reflexes are absent in brain deathCorneal reflexes - tested by using a cotton-Corneal reflexes - tested by using a cotton-

tipped swabtipped swabGrimacing in response to pain can be tested Grimacing in response to pain can be tested

by applying deep pressure to the nail beds, by applying deep pressure to the nail beds, supra-orbital ridge, TMJ, or swab in nosesupra-orbital ridge, TMJ, or swab in nose

Severe facial trauma can inhibit interpretation Severe facial trauma can inhibit interpretation of facial brain stem reflexes of facial brain stem reflexes

Basic exam 5Basic exam 5Pharyngeal and tracheal reflexesPharyngeal and tracheal reflexes

Both gag and cough reflexes are absent in Both gag and cough reflexes are absent in patients with brain deathpatients with brain deathGag reflex can be evaluated by stimulating Gag reflex can be evaluated by stimulating

the posterior pharynx with a tongue blade, but the posterior pharynx with a tongue blade, but the results can be difficult to evaluate in orally the results can be difficult to evaluate in orally intubated patientsintubated patients

Cough reflex can be tested by using ETT Cough reflex can be tested by using ETT suctioning, past end of ETTsuctioning, past end of ETT

Basic exam 6Basic exam 6ApneaApnea

PPaaCOCO22 levels greater than 60 mmHg, levels greater than 60 mmHg, ≥≥20 20 mmHg over baselinemmHg over baseline

Technique:Technique:Pre-oxygenate with 100% oxygen several minPre-oxygenate with 100% oxygen several minAllow baseline PAllow baseline PaaCOCO22 to be ~40 mmHg to be ~40 mmHgPlace pt on CPAP or bag-ETTPlace pt on CPAP or bag-ETTObserve for respiratory effort for ~6 minutesObserve for respiratory effort for ~6 minutesGet ABG to determine PGet ABG to determine PaaCOCO22

Apneic oxygenationApneic oxygenation

Confirmatory testingConfirmatory testing

EEGEEG30 minutes30 minutes

4 vessel angiography4 vessel angiographyCerebral blood flow = perfusion scanCerebral blood flow = perfusion scan

Cerebral perfusion scanCerebral perfusion scan

Kids over 1 year oldKids over 1 year old Absence of all brain and brainstem functionAbsence of all brain and brainstem function

Comatose: no purposeful response to any stimulusComatose: no purposeful response to any stimulus Brainstem function is absent when: Brainstem function is absent when:

Pupils are mid-position and do not react to lightPupils are mid-position and do not react to light Eyes does not blink when touched (corneal reflex)Eyes does not blink when touched (corneal reflex) Eyes do not rotate in the socket when the head is moved Eyes do not rotate in the socket when the head is moved

from side to side (oculo-cephalic reflex).from side to side (oculo-cephalic reflex). Eyes do not move when ice water is placed in the ear canal Eyes do not move when ice water is placed in the ear canal

(oculo-vestibular reflex)(oculo-vestibular reflex) Child does not cough or gag when a suction tube is placed Child does not cough or gag when a suction tube is placed

deep into the breathing tubedeep into the breathing tube Child does not breathe when taken off the ventilatorChild does not breathe when taken off the ventilator

Repeat in ~6 hoursRepeat in ~6 hours

Children under 1 yearChildren under 1 year Necessary to repeat the clinical examination after an Necessary to repeat the clinical examination after an

‘appropriate’ observation period has passed‘appropriate’ observation period has passed Confirmatory EEG Confirmatory EEG unlessunless it is determined that there is no it is determined that there is no

blood flow to the brainblood flow to the brain

Age 7 days to 2 monthsAge 7 days to 2 months Two examinations 48 hours apart and one EEG Two examinations 48 hours apart and one EEG

Age 2 months-1 yearAge 2 months-1 year Two examinations 24 hours apart and one EEG or Two examinations 24 hours apart and one EEG or perfusion scanperfusion scan

Repeat examination and EEG are Repeat examination and EEG are notnot necessary if it is necessary if it is determined that there is no cerebral blood flowdetermined that there is no cerebral blood flow

Common misconceptionsCommon misconceptions

Since there is a heartbeat, he is aliveSince there is a heartbeat, he is aliveBrain dead pts have permanently lost the Brain dead pts have permanently lost the

capacity to think, be aware of self or capacity to think, be aware of self or surroundings, experience, or communicate surroundings, experience, or communicate with otherswith others

He’s in a comaHe’s in a comaReinforce that they are deadReinforce that they are dead

With rehab/time he’ll get betterWith rehab/time he’ll get better Irreversible, dead brain cells do not regrowIrreversible, dead brain cells do not regrow

How to make it clearHow to make it clear

Say “dead”, not “brain dead”Say “dead”, not “brain dead”Say “artificial or mechanical ventilation”, Say “artificial or mechanical ventilation”,

not “life support”not “life support”Time of death = neurologic determinationTime of death = neurologic determination

NOT when ventilator removedNOT when ventilator removedNOT when heart beat ceasesNOT when heart beat ceases

Do not say “kept alive” for organ donationDo not say “kept alive” for organ donationDo not talk to the pt as if he’s still aliveDo not talk to the pt as if he’s still alive

Organ donationOrgan donation Call LifeLink for all deathsCall LifeLink for all deaths

Donor or not in your eyesDonor or not in your eyes Tissue – bone, corneas, heart valvesTissue – bone, corneas, heart valves

Mentioning organ donation to familyMentioning organ donation to family LifeLink will approach them after the child is declared, LifeLink will approach them after the child is declared,

but this approach may (will) be changing back to but this approach may (will) be changing back to times when the PICU docs talked with the parentstimes when the PICU docs talked with the parents

If family asks you about donationIf family asks you about donation Acknowledge that it is a wonderful gift they are Acknowledge that it is a wonderful gift they are

consideringconsidering Tell them you will contact LifeLink to have them Tell them you will contact LifeLink to have them

available for questionsavailable for questions Contact LifeLink ASAPContact LifeLink ASAP