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How to Diagnose Brainstem Death

Akhmad ImronDept./SMF Bedah Saraf FK.Unpad/RSHS

RSUP Dr. Hasan Sadikin BandungJalan Pasteur No. 38 Bandung telephone.62-022-2034953/57 Fax.62-022-2032216

Diagnosis of death: as having occurred when the vital functions of respiration and circulation have ceased.

The advent of intensive care, the diagnosis of death has become much more difficult.

Death entails the irreversible loss of the essential characteristics that are necessary for existence.

Recommended by the UK Department of Health : ‘irreversible loss of the capacity for consciousness, combined with irreversible loss of the capacity to breathe spontaneously’.

Diagnosing this ‘loss of the capacity for consciousness’ raises many medical, religious and philosophical questions.

Does brainstem death alone equate to death of the individual (as in the UK), or is it necessary to prove death of the whole brain, including the brainstem (as in the USA and many European countries)?

Whichever approach is chosen, brainstem death results in inevitable asystole, even if maximal supportive therapy is continued.

In the UK, three steps are involved in making a diagnosis of brainstem death:

ensuring that certain preconditions have been met

excluding reversible causes of apnoeic coma clinical examination confirming brainstem

areflexia and documenting persistent apnoea.

The brainstem is composed of the midbrain, pons and medulla. It contains the:

nuclei of the third to twelfth cranial nerves respiratory, cardiac and vasomotor centres the reticular formation descending motor and ascending sensory

tracts.

Bosnell L, Madder H. Conceps of brain death. In Surgery. Elsevier. 2011. p.289-294

Stimulation of the reticular formation is associated with widespread cortical activity and wakefulness; conversely, any lesion interrupting the reticular formation tends to cause coma.

The reticular formation and its projections can be thought of as generating the capacity for consciousness, while the content of consciousness is a function of activated cerebral hemispheres.

Kematian batang otak : hilangnya seluruhfungsi otak, termasuk fungsi batang otak, secara ireversibel.

Tiga tanda utama manifestasi kematian batangotak : koma dalam, hilangnya seluruh refleksbatang otak, dan apnea.

Seorang pasien yang telah ditetapkanmengalami kematian batang otak berarti secaraklinis dan legal-formal telah meninggal dunia.(Pernyataan IDI tentang Mati dalam SK PB IDI No.336/PB IDI/a.4 tertanggal 15 Maret 1988 yang disusul dengan SK PB IDI No.231/ PB.A.4/07/90)

Fatwa: seorang dikatakan mati, bila fungsipernafasan dan jantung telah berhenti secarapasti atau irreversible, atau terbukti telahterjadi kematian batang otak.

The timing of brainstem tests and the personnel involved varies widely from country to country.

In the UK, at least two medical practitioners who have been registered for more than five years, are competent in the field and are not members of the transplant team. At least one of the doctors should be a consultant.

To reduce the risk of observer error, two sets of tests should always be performed, which the two practitioners may carry out separately or together.

Kolegium Neurologi, Modul Kematian Batang Otak,2015

In the UK, the timing of the interval between the two sets of tests (the observation period) is a matter for clinical judgement, but the time should be adequate for the reassurance of all those directly concerned.

The interval between the tests will depend on the:

primary pathology clinical course of the disease progress of the patient.

Although death is not pronounced until the second test has been completed, the ‘legal’ time of death is when the first test indicates brainstem death.

In many countries, the minimum observation period between the sets of tests is specified, varying between 2 and 36 hours. This period is often extended if hypoxia is a possible cause of brainstem death.

For example, in Switzerland, the observation period is increased from 6 hours to 48 hours, and in Australia the period is increased from 2 hours to 12 hours.

In many countries, performing confirmatory tests of brain death can reduce the recommended observation periods.

The personnel requirements for brainstem death testing (number of staff, their background and training requirements) vary widely between countries.

Steps are Involved in Making a Diagnosis of Brainstem Death

Ensuring that certain preconditions have been met

Excluding reversible causes of apnoeic coma Clinical examination confirming brainstem

areflexia and documenting persistent apnoea.

Kolegium Neurologi, Modul Kematian Batang Otak,2015

The patient should be deeply unconscious Patient ventilation: the patient is maintained

on a ventilator. Brain damage: the patient’s condition must be

due to irremediable brain damage of known aetiology.

Depressant drugs there should be no evidence that the deeply unconscious state is due to drugs that depress the CNS.Acute drug intoxication is common amongst patients admitted to the ICU. Many patients will have been given anaesthetic drugs and sedatives (e.g. benzodiazepines, opioids)

It is essential that the drug history is carefully reviewed, since hypothermia and renal or hepatic impairment can influence drug metabolism. If necessary, plasma drug levels can be obtained or antagonists administered.

Primary hypothermia as the cause of unconsciousness must be excluded (i.e. core temperature should be above 35oC).

Disturbances – potentially reversible circulatory, metabolic and endocrine disturbances must be excluded (e.g. diabetes insipidus leading to hypernatraemia)

Muscle relaxants and other drugs (opioids, benzodiazepines) must be excluded as a cause for respiratory inadequacy or failure.

The use of neuromuscular blocking drugs

Clinical examination confirming brainstem areflexia and documenting persistent apnoea

The pupils are fixed and do not respond to bright light

There is no corneal reflex The vestibulo–ocular reflexes are absent No motor responses within the cranial nerve

distribution can be elicited by adequate stimulation of any somatic area

There is no gag reflex or reflex response to bronchial stimulation

No respiratory movements occur when the patient is disconnected from the ventilator

Oculocephalic reflex (Doll’s eye reflex)


From Youtube

The determination of brain death is based on a comprehensive clinical assessment.

A confirmatory test—at least, in adult patients in the United States—is not mandatory, but it typically is used as a safeguard or added when findings on clinical examination are unwontedly incomplete.

In other countries, confirmatory tests are mandatory; in many, they are optional.

Cerebral electrical activity EEG

Cerebral evoked responsBrainstem auditory evoked responses Somatosensory evoked potentials Motor evoked potentials

Cerebral blood flow:4-vessel cerebral angiogram, Transcranial Doppler (TCD) ultrasonographic scan, Magnetic resonance angiogram, CT angiogram Nuclear brain scanIsotope scans, usually with 99Tc-HMPAO Positron emission tomography (PET) with H215O

Cerebral metabolism PET with labelled glucose or 15O2

Jugular bulb oxygen saturation

Cerebral angiogram Image variability with injection of arch or selective arteriesImage variability with injection and/or push techniqueNo guidelines for interpretation

Transcranial Doppler ultrasonographic scan Technical difficulties and skill-dependent Normal in anoxic-ischemic injury

ElectroencephalogramArtifacts in intensive care settings Information primarily from cortex only

Somatosensory-evoked potentials Absent in comatous patients without brain death

Computed tomography angiogramInterpretation difficulties Retained blood flow in 20% of casesPossibility of missing slow-flow states because of rapid acquisition of images

Nuclear brain scan Areas of perfusion in thalamus in patients with anoxic injury or skull defect

The diagnosis of brainstem death in children (especially in neonates and small babies) is difficult.

There may be greater capacity for the immature brain to withstand hypoxia, and pre- mature neurological assessments in children may be particularly misleading.

In the UK, the brainstem death criteria for children over the age of 2 months are the same as for those in adults. Between 37 weeks, gestation and 2 months of age, it is rarely possible to confidently diagnose brainstem death, and below 37 weeks of gestation, the criteria for brainstem death cannot be applied.

In the USA, confirmatory tests of brain death are mandatory in children, but optional in adults.

In Japan, children less than 6 years of age are excluded from a diagnosis of brainstem death.

The diagnosis of brainstem death is an emotive subject.

Families often have difficulty reconciling their own ideas about death with the warm, perfused relative that they see before them.

Some cultures and religions (e.g. Judaism) believe that life exists as long as the heart functions and blood circulates, and they may not equate brainstem death to the death of the individual.

Dealing with these issues requires communication and understanding.

One wishes to be sensitive to the family’s (and possibly the patient’s) beliefs.

Conversely, the brain-centred definition of death is a legal definition in many countries, and it may be legally, morally and ethically unacceptable to prolong treatment and use scarce resources knowing that asystole is inevitable.

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From Youtube

How to Diagnose Brainstem Death


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