OBJECTIVE: We sought to identify similarities and differences in the diagnostic 
requirements for ancillary testing for determination of brain death/death by 
neurologic criteria (BD/DNC) around the world.
METHODS: We reviewed diagnostic requirements for ancillary testing for BD/DNC in 
78 unique official national BD/DNC protocols obtained from contacts worldwide 
between January 2018 and April 2019.
RESULTS: Details provided on the performance and interpretation of ancillary 
tests for determination of BD/DNC were variably provided and inconsistent. 
Approximately half of all protocols that included each ancillary test provided 
details about study performance: 63% of protocols that included conventional 
cerebral angiography, 55% of protocols that included electroencephalography, 50% 
of protocols that included somatosensory evoked potentials, 48% of protocols 
that included transcranial Doppler ultrasonography, 43% of protocols that 
included nuclear medicine flow study and 41% of protocols that included 
brainstem auditory evoked potentials. Similarly, about half of all protocols 
that included each ancillary test provided details about study interpretation: 
66% of protocols that included electroencephalography, 59% of protocols that 
included brainstem auditory evoked potentials, 56% of protocols that included 
somatosensory evoked potentials, 55% of protocols that included transcranial 
Doppler ultrasonography, 52% of protocols that included conventional cerebral 
angiography and 49% of protocols that included nuclear medicine flow study.
INTERPRETATION: Diagnostic requirements for ancillary testing in BD/DNC 
determination vary around the world. We hope that the World Brain Death Project 
will improve worldwide consensus on the diagnostic requirements for ancillary 
testing in BD/DNC, both for performance and interpretation.