Brain Death

مدبولى/ جودة المنعم عبد مدبولى/ د جودة المنعم عبد ددكتوراة الطب الشرعي و السموم اإلكلينيكية,

, اإلكلينيكية السموم و الشرعي الطب مدرسالجامعي بنها بمستشفى التسمم عالج استشاري

الجودة بوحدة المقررات و البرامج مراجعة لجنة عضو

Brain Death Objectives: Concept of brain death.Concept of brain death. Definition.Definition.

Types of brain death.Types of brain death.

Causes of brain death.Causes of brain death. Diagnosis of brain death.Diagnosis of brain death.

Medico-legal implications of brain death.Medico-legal implications of brain death.

DefinitionDefinition::

IrreversibleIrreversible cessation of functions of cessation of functions of the entire brainthe entire brain, , including the including the brainstembrainstem that is that is clinically clinically ascertainableascertainable..

TypesTypes::

1.1. Cortical deathCortical death ((persistent persistent

vegetative state vegetative state = = PVSPVS = = coma coma prolonged.prolonged.

2.2. Brain stem deathBrain stem death ((coma coma depasse)depasse)..

3.3. Whole brain deathWhole brain death = 2.= 2.

CausesCauses::

Causes outside brain Causes outside brain (2nd brain death):(2nd brain death): Due to respiratory and cardiac arrest. Due to respiratory and cardiac arrest. It It equated to somatic deathequated to somatic death. . No medical or legal or religious problems.No medical or legal or religious problems.

Causes within the brain Causes within the brain (1ry brain (1ry brain death):death):

Due to structural brain damage that cause brain stem Due to structural brain damage that cause brain stem death. death.

It includes, head trauma, poisoning and other brain It includes, head trauma, poisoning and other brain lesions (tumor).lesions (tumor).

There are medical, legal and religious problems.There are medical, legal and religious problems.

DiagnosisDiagnosis::

Preconditions:Preconditions:1.1. Patients selection.Patients selection.

2.2. Doctor selection.Doctor selection.

3.3. Time of examination.Time of examination. Exclusions.Exclusions. Diagnostic criteria.Diagnostic criteria. Repeat examination.Repeat examination. Medico-legal Implications.Medico-legal Implications.

PreconditionsPreconditions::

Patients selection:Patients selection: The diagnosis must give an etiology that The diagnosis must give an etiology that

confirms that the damage is irreversible confirms that the damage is irreversible ((irremediable structural brain damageirremediable structural brain damage).).

The patient must be in The patient must be in unresponsive apnic unresponsive apnic comacoma, though spinal reflexes do not exclude , though spinal reflexes do not exclude the diagnosis.the diagnosis.

ExclusionsExclusions::

Reversible causes of coma must be Reversible causes of coma must be excluded:excluded:

Drug toxicityDrug toxicity, such as narcotics, muscle , such as narcotics, muscle relaxants, or hypnotics. relaxants, or hypnotics.

Metabolic or endocrineMetabolic or endocrine causes such as causes such as hypoglycaemia, hyperglycaemia, hyponatraemia, hypoglycaemia, hyperglycaemia, hyponatraemia, hepatic failure, uraemia, myxoedema, or Reye's hepatic failure, uraemia, myxoedema, or Reye's syndrome.syndrome.

HypothermiaHypothermia there is no fixed recommendation, there is no fixed recommendation,

but testing should be done at higher than but testing should be done at higher than 35°C35°C..

Diagnostic criteriaDiagnostic criteria:: Coma with flat EEG.Coma with flat EEG. Absence of brainstem reflexes:Absence of brainstem reflexes:

- - Barany’s test Barany’s test ((Vestibulo-ocular R.)Vestibulo-ocular R.) - - Doll’s = Cantellis sign Doll’s = Cantellis sign ((Oculocephalic R.)Oculocephalic R.) Absence of spontaneous respiration Absence of spontaneous respiration

(Apnoea test).(Apnoea test).

++ Confirmatory tests of brain death.Confirmatory tests of brain death.

Apnea testing:Apnea testing:– At the beginning, the ventilator should be set to deliver At the beginning, the ventilator should be set to deliver 100 100

per cent oxygen (for more than 10 min).per cent oxygen (for more than 10 min). – A blood gas may be taken. A blood gas may be taken. – The patient is disconnected from the ventilator and oxygen The patient is disconnected from the ventilator and oxygen

is insufflated is insufflated via a catheter into the tracheal tubevia a catheter into the tracheal tube. . – In apnea the In apnea the PaCO2 risesPaCO2 rises at between only 0.5 and 1 at between only 0.5 and 1

kPa/min. kPa/min. – Careful observation of the patient for respiratory Careful observation of the patient for respiratory

movements during the disconnection continues until a movements during the disconnection continues until a blood gas shows that the PaCO2 has risen to more than 7 blood gas shows that the PaCO2 has risen to more than 7 kPa (kPa (just over 50 mmHgjust over 50 mmHg). ).

– Oxygenation is usually well maintained. Oxygenation is usually well maintained. – The patient is usually The patient is usually reconnectedreconnected to the ventilator once to the ventilator once

the target PaCO2 is reached if this is the first testing, or if the target PaCO2 is reached if this is the first testing, or if organ donation is planned.organ donation is planned.

Repeat examinationRepeat examination::

A second testing is done at a later time

To remove the risk of observer error.

The interval betweenThe interval between the tests is the tests is not fixednot fixed, , but usually between but usually between 1 and 6 h (few hs)1 and 6 h (few hs)

Medicolegal implicationsMedicolegal implications::

I- Harvesting of organs:I- Harvesting of organs: Informed consent:Informed consent:1.1. Patient while being healthy.Patient while being healthy.2.2. Family.Family.3.3. Forensic pathologist.Forensic pathologist.

After harvesting organs machine After harvesting organs machine is off and death is declaredis off and death is declared..

II- Maintenance or removal of life II- Maintenance or removal of life

supportsupport:: Made by treating doctors not transplanting Made by treating doctors not transplanting

doctors, depending on:doctors, depending on:1.1. Human dignity.Human dignity.

2.2. Family distress.Family distress.

3.3. Practical need for ICU.Practical need for ICU.