When do you order ancillary tests to determine brain death?

Nathaniel M. Robbins, James L. Bernat.  When do you order ancillary tests to determine brain death?

Neurology: Clinical Practice June 2018 vol. 8 no. 3 1-9.

Abstract

Brain death has been accepted as a legal definition of death in most countries, but practices for

determining brain death vary widely. One source of variation is in the use of ancillary tests to

assist in the diagnosis of brain death. Through case-based discussions with 3 experts from 3

continents, this article discusses selected aspects of brain death, with a focus on the use of

ancillary tests. In particular, we explore the following questions: Are ancillary tests necessary, or

is the clinical examination sufficient? What ancillary tests are preferred, and under which

circumstances? Are ancillary tests required when the primary mechanism of injury is brainstem

injury? Should the family’s wishes play a role in the need for ancillary tests? The same casebased

questions were posed to the rest of our readership in an online survey, the preliminary

results of which are also presented.

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From the srticle:

We collected a total of 117 complete questionnaires since April 6, 2018, primarily from general neurologists (80%) treating adults (77%) in a hospital setting (74%). Most responders were attending physicians (77%) practicing in the United States (58%).

For the first case regarding cessation of cortical and brainstem function after TBI with inability to perform an apnea test due to pulmonary edema, there is consensus among survey takers to request ancillary testing to confirm brain death (n = 101 [86%]). Half of the respondents chose to perform at least an EEG (n = 50); 21% also recommended a radionuclide angiography and 18% a TCD [transcranial Doppler ultrasonography].

Our survey takers were then presented with a challenging pediatric case of a 10-year-old girl who became comatose and apneic due to delayed treatment of bacterial meningitis. While the majority of responders were satisfied with the clinical examination and apnea test to diagnose brain death, 49 (42%) requested ancillary tests, especially EEG (n = 32). When asked if they would change their mind in case parents were skeptical of the diagnosis and order some tests, half of survey takers held steady and said no. For those who had already decided to order ancillary tests initially, if the parents were still skeptical of the diagnosis, 40% would proceed to order more tests. This case highlights the complex nuances of brain death in children and the delicate interaction that often occurs between the family and the physician, which may sometimes result in altering the decision-making. In fact, 60 survey takers (51%) admitted that family requests have influenced their decision in at least 10% of cases they have managed and it is possible that this percentage would be higher if more pediatric neurologists had taken the survey.

For the third case regarding apnea, coma, and cessation of brainstem function in case of extensive brainstem hypertensive hemorrhage, 40% of survey takers would order ancillary tests, at least to include an EEG (n = 32). After the ICU staff saw a limb movement, an EEG was obtained and showed low-amplitude irregular delta activity and TCD ultrasound found pulsations of intracranial arteries. Presented with this information, 55% of responders stated that the patient could not be considered brain dead anymore. Opinions were split almost in half on whether brainstem death is sufficient to declare brain death.