The Society of Critical Care Anesthesiologists

Update on the Brain Death and Death by Neurological Criteria 2023 Guidelines

In 2023, the American Academy of Pediatrics, Child Neurology Society, Society for Critical Care Medicine and the American Academy of Neurology released an updated set of guidelines for Brain Death/Death by Neurologic Criteria (BD/DNC). These were the first guidelines to provide recommendations for both adult and pediatric patients. Though many of the recommendations are similar, there are several important updates.

The complete set of updated guidelines is listed below. Highlights include the following:

The 2023 guidelines require both minimum systolic blood pressure and mean arterial pressure

Observe for at least 24-48 hours after insult or surgery or initial therapies to address ICP before initiating testing

Wait at least 24 hours after rewarming before initiating testing

Evidence of neuroendocrine function does not preclude testing (for e.g diabetes insipidus)

Ancillary testing should not be used in the setting of hypothermia, high levels of CNS depressing medications, solely because of the presence of an open fontanelle, skull fracture, skull defect, or cerebrospinal fluid diversion device

Electroencephalography and auditory-evoked potentials are no longer considered acceptable ancillary tests

No obligation to obtain consent prior to testing

Pregnancy is not a contraindication to BD/DNC evaluation

Prerequisites for clinical examination

Patient has sustained a catastrophic, permanent brain injury caused by an identified mechanism that is known to lead to BD/DNC

Neuroimaging consistent with mechanism and severity of brain injury (in patients with primary posterior fossa injury, neuroimaging should demonstrate catastrophic supratentorial injury)

Observation of permanency

Greater than or equal to 48 hours after acute brain injury in patients less than 2 years old

Greater than or equal to 24 hours after hypoxic ischemic brain injury if greater than 2 years old

Enough time after injury to ensure there is no potential for recovery of brain function as determined by the evaluator based on the pathophysiology of the brain injury

Core body temperature greater than or equal to 36 degrees Celsius (for greater than 24 hours in patients whose core temperature has been less than 35.5 degrees Celsius)

Systolic blood pressure greater than or equal to 100 and mean arterial pressure greater than or equal to 75 and greater than or equal to 5th percentile for age in children, for patients on ECMO – MAP greater than or equal to 75 and greater than or equal to 5th percentile for children

Exclusion of pharmacologic paralysis if administered or suspected through train of four stimulation or demonstration of deep tendon reflexes

Subtherapeutic/therapeutic drug levels of agents that may depress the central nervous system or at least five half-lives have passed since last administration

Alcohol blood level less than or equal to 80

Urine/blood toxicology is negative (if clinically indicated)

Exclusion of severe metabolic, acid-base, and endocrine derangements

Reasonable attempt has been made to contact family and inform them of plan for BD/DNC testing

Clinical exam

Coma with unresponsiveness to visual, auditory, and tactile stimulation

Absent motor responses, other than spinally mediated reflexes, of the head/face, neck, and extremities after application of noxious stimuli to the head/face, trunk, and limbs

Absent pupillary responses to bright light bilaterally

Absent oculocephalic reflex (unless concern for cervical spine integrity)

Absent oculovestibular reflexes bilaterally

Absent corneal reflexes bilaterally

Absent gag reflex 

Absent cough reflex 

Apnea test

No hypoxemia, hypotension, hypovolemia

pH is normal (7.35-7.45) and PaCO2 is normal (35-45) or if the patient is known to have chronic hypercarbia, PaCO2 is at baseline (if known) or estimated baseline

PaO2 > 200

Apnea confirmed if no respirations and pH < 7.3 and PaCO2 > 60 and >20 above pre-apnea test baseline

Ancillary testing is required if patient is known/suspected to have chronic hypercarbia, but baseline PaCO2 is not known.

Ancillary testing options in the 2023 guidelines include: 

Conventional 4-vessel catheter angiography (digital subtraction angiography)

SPECT radionuclide perfusion scintigraphy or planar radionucleotide angiography

Transcranial doppler ultrasonography 

References

Neurology: Clinical Practice 2023;13:e200189. doi:10.1212/CPJ.0000000000200189

Neurology® 2023;101:1112-1132. doi:10.1212/WNL.0000000000207740