Reviewed and revised 2 May 2013
Changes in Brain Death Consensus Statement (V3.2 2013)
Preconditions (additions to v3.1)
- Particular care should be taken to ensure the absence of continued sedative drug effect in patients who have received therapeutic hypothermia (e.g. post cardiac arrest).
- In the case of barbiturates, which take many days to metabolise, including thiopentone in high dose or by infusion, either blood levels of barbiturates should be shown to be below that of clinically significant effects at least < 10mg/L or brain death should be determined by demonstration of absent cerebral blood flow.
- intact neuromuscular function — unless it is known for certain that neuromuscular-blocking drugs have not been administered, a peripheral nerve stimulator or other recognised method (e.g. electromyography) should always be used to confirm that neuromuscular conduction is normal.
- All preconditions must be fulfilled before and throughout the 4 hour waiting period of observation, before clinical examination can begin.
Clinical Testing of Brain-Stem Function (additions to v3.1)
- Return of brain function may be delayed for more than four hours after resuscitation from cardiorespiratory arrest. It is therefore recommended that, in cases of acute hypoxic-ischaemic brain injury, clinical testing for brain death be delayed for at least 24 hours subsequent to the cardiorespiratory arrest restoration of spontaneous circulation. Brain death may be determined prior to this 24 hours by demonstration of absent cerebral blood flow.
- Therapeutic hypothermia may modify outcome prediction after cardiac arrest and there are published case reports suggesting that determination of brain death might be confounded either by hypothermia itself or by impaired clearance of associated medications. It is therefore recommended, when induced hypothermia has been used after resuscitation from cardiorespiratory arrest, that clinical testing for brain death be delayed for at least 24 hours after rewarming. Brain death may be determined prior to 24 hours by demonstration of absent cerebral blood flow.
Demonstrating the Absence of Intracranial Blood Flow.
- Prior to proceeding with any investigation a clinical examination should be performed to ensure absence of responsiveness (GCS 3), brain-stem reflexes and spontaneous breathing effort. If a complete examination is not possible (e.g. eye or ear trauma) or apneoa testing precluded (e.g. severe lung injury or high cervical trauma), then that part of the clinical examination that can be performed, should be undertaken. Any responsiveness or breathing effort will preclude proceeding with a contrast study.
- In addition, before any investigation, there ideally will have been at least four hours observation of unresponsiveness and no spontaneous breathing effort. This will increase the likelihood that the test will confirm absent intracranial blood flow.
- Transcranial Doppler (TCD) may be used as a screening test to optimise the timing of the contrast study, the aim being to avoid performing the contrast study before cessation of intracranial blood flow and thus reduce the need to repeat the contrast study.
Changes in Brain Death Consensus Statement (V3 2010)
Minimum time of observation and mechanical ventilation prior to Preconditions assessment
- was 4 hours of observation +2 hours between examinations
- no situation where the two examination have differed so no foundation for this
- The need for 2 hours between testing was removed
Brain death to be certified by 2 medical practitioners
- time of brain death occurs at the time of completion of the second test.
Recognition of Donation after Cardiac Death