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 (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
- Pre-oxygenate patient for 10 min at 100% FiO2
- Check pre-apnea test arterial blood gas to confirm PaCO2 34-45 mmHg
- Monitor for 8-10 minutes for spontaneous respirations unless patient becomes unstable
- Draw post-apnea test arterial blood gas prior to reconnecting 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
- HMPAO SPECT
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.
The online version of the full article, along with updated information and services, is located on the World Wide Web at: http://www.neurology.org/cgi/content/full/74/23/1911.
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.
- A free online course that outlines the accepted medical standards for determining death by neurological criteria and provide clinicians with the tools to effectively diagnose death by neurological criteria.