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Determination of Death by Neurological Criteria
In 2010, the American Academy of Neurology updated guidelines for determining brain death in adults. Prior to the neurological examination, the patient must meet clinical prerequisites. Once the neurological examination is completed, an apnea test should be conducted. It only needs to be conducted once. If clinical prerequisites cannot be met or any portion of the neurological examination or apnea test cannot be conducted, an ancillary test is recommended.
Clinical Evaluation Prerequisites
- Coma, irreversible and cause known
- Neuroimaging explains coma (or is consistent with the cause of a coma)
- CNS depressant drug effect absent
- No evidence of residual paralytics
- Absence of severe acid-base, electrolyte, or endocrine abnormality
- Normothermia or mild hypothermia (core temp 36 C — 38 C)
- Systolic blood pressure ≥ 100 mm Hg
- No spontaneous respirations
- Pupils nonreactive to bright light
- Corneal reflex absent
- Oculocephalic reflex absent (test only if C‑spine integrity ensured)
- Oculovestibular reflex absent
- No facial movement to noxious stimuli at supraorbital nerve, temporomandibular joint
- Gag reflex absent
- Cough reflex absent to tracheal suctioning
- Absence of motor response to noxious stimuli in all 4 limbs (spinally mediated reflexes are permissible)
- Ensure patient is hemodynamically stable
- Adjust ventilator to provide normocarbia (PaCO2 34 – 45 mmHg)
- Preoxygenate patient with 100% FiO2 for 10 minutes to PaO2 200 mmHg
- Patient well-oxygenated with a PEEP of 5 cm of water
- Provide O2 via suction catheter to the level of the carina at 6 L/min or attach T piece with CPAP at 10 cm H20
- Disconnect ventilator and monitor for spontaneous respirations
- Draw arterial blood gas at 8 – 10 minutes and reconnect patient to the ventilator
An apnea test is considered positive if the PCO2 is 60 mmHg or rises ≥ 20 mmHg normal baseline value.
In instances in which a component of the neurological examination or apnea test cannot be completed, ancillary testing can be used to confirm brain death.
- Cerebral angiogram
- Nuclear med flow study
- HMPAO SPECT
- EEG (optional)
- TCD (optional)
Wijdicks F.M., Varelas P.N., Gronseth G.S., Greer D.M. Evidence-based guideline update: determining brain death in adults: report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 2010; 74:1911 – 1918.
In pediatrics, it is recommended that two physicians must perform independent examinations separated by specified time intervals.
Term newborns 37 weeks gestational age up to 30 days old:
- First exam may be performed 24 hours after birth or following cardiopulmonary resuscitation or other severe brain injury
- Time intervals between tests should be at least 24 hours unless an ancillary study is performed and is consistent with brain death
In 31 days to 18 year olds:
- First exam may be performed 24 hours following cardiopulmonary resuscitation or other severe brain injury
- Time intervals between tests should be at least 12 hours unless an ancillary study is performed and is consistent with brain death
Nakagawa T. et al. Guidelines for the determination of brain death in infants and children: an updated of the 1987 task force recommendations. Crit Care Med. 2011; 39:2139 – 2155.