UMEM Educational Pearls

Category: Critical Care

Title: Determination of Brain Death

Keywords: brain death (PubMed Search)

Posted: 1/14/2014 by Feras Khan, MD
Click here to contact Feras Khan, MD

Determination of Brain Death

With the recent media spotlight on brain death (irreversible end of brain activity) due to a few recent cases, it would be helpful to review the definition.
Rule out alternative causes including hypothermia, drug-induced coma, metabolic abnormalities, or severe electrolyte disturbances.
A clear irreversible cause must be known based on history and diagnostic studies.

Clinical Examination

Patient should be unresponsive to verbal or noxious stimulation, with the exception of spinally mediated responses.
Absence of brainstem Reflexes

No pupillary response
Absent corneal reflex
Absent gag and cough reflex
Absent cervico-ocular reflex (Doll’s Eyes Maneuver)
Absent vestibulo-ocular reflex (Cold Calorics)

Apnea Testing (disconnecting the ventilator and evaluating respiratory drive)

If apnea testing cannot be performed due to instability, hypoxia, or cardiac arrhythmias, then a confirmatory test should be performed (from highest to lowest sensitivity):

Angiography (lack of intracranial flow)
EEG
Transcranial Doppler
Technetium-99 brain scan
Somatosensory evoked potentials

There is state to state variation on who can perform the test and how many separate examinations need to be performed before brain death can be legally declared.

For a great review on some of the pitfalls in making the diagnosis and difficulties with the examination, please see the attached article.

References

2001 Apr 19;344(16):1215-21.

The diagnosis of brain death.

Wijdicks EF.

Attachments

1401141409_pitfalls_in_brain_death,_wijdicks.pdf (93 Kb)