Faculty Bibliography

In collaboration with the American Academy of Pediatrics, Child Neurology Society, and Society for Critical Care Medicine, the American Academy of Neurology formulated an updated, evidence-informed consensus-based guideline for pediatric and adult brain death/death by neurologic criteria (BD/DNC) determination. In comparison with the prior guidelines, the revisions and additions in this guideline, which are summarized in this review, are intended to (1) ensure recommendations are conservative, yet practical, and emphasize circumstances in which BD/DNC determination should be delayed or deferred, so as to minimize the risk of a false-positive BD/DNC determination; and (2) provide guidance about aspects of BD/DNC determination that clinicians find challenging and/or controversial. We hope that clinicians throughout the United States will use this information to revise their hospital BD/DNC determination policies to conform to the standardized process for BD/DNC determination described in the new guideline, to ensure that every BD/DNC evaluation is consistent and accurate.

Although the fundamental principle behind the Uniform Determination of Death Act (UDDA), the equivalence of death by circulatory-respiratory and neurologic criteria, is accepted throughout the United States and much of the world, some families object to brain death/death by neurologic criteria. Clinicians struggle to address these objections. Some objections have been brought to court, particularly in the United States, leading to inconsistent outcomes and discussion about potential modifications to the UDDA to minimize ethical and legal controversies related to the determination of brain death/death by neurologic criteria.

The Uniform Determination of Death Act (UDDA) revision series in Neurology® originated in response to the Uniform Law Commission's plan to create a revised Uniform Determination of Death Act (rUDDA) to address contemporary controversies associated with brain death/death by neurologic criteria (BD/DNC) determination. This article contextualizes these, and other, controversies and reviews the extent to which they represent potential threats and impediments to the clinical practice of BD/DNC determination. It also explains the reasons that our rapidly evolving understanding of the brain's ability to recover from injury should not influence the clinical practice of BD/DNC determination. Finally, it explores the myriad ways in which the American Academy of Neurology has addressed potential threats and impediments to the clinical practice of BD/DNC determination and the implications potential changes to the UDDA may have on the future of the clinical practice of BD/DNC determination.

Use of thoracoabdominal normothermic regional perfusion (TA-NRP) during donation after circulatory death (DCD) is an important advance in organ donation. Prior to establishing TA-NRP, the brachiocephalic, left carotid, and left subclavian arteries are ligated, thereby eliminating anterograde brain blood flow via the carotid and vertebral arteries. While theoretical concerns have been voiced that TA-NRP after DCD may restore brain blood flow via collaterals, there have been no studies to confirm or refute this possibility. We evaluated brain blood flow using intraoperative transcranial Doppler (TCD) in two DCD TA-NRP cases. Pre-extubation, anterior and posterior circulation brain blood flow waveforms were present in both cases, similar to the waveforms detected in a control patient on mechanical circulatory support undergoing cardiothoracic surgery. Following declaration of death and initiation of TA-NRP, no brain blood flow was detected in either case. Additionally, there was absence of brainstem reflexes, no response to noxious stimuli and no respiratory effort. These TCD results demonstrate that DCD with TA-NRP did not restore brain blood flow.

There is a need for the neuroscience community to advocate for uniformity in the determination of brain death/death by neurologic criteria (BD/DNC). Engagement with state medical societies is one example of this type of advocacy. After determining that her hospital policy on determination of BD/DNC was unclear and inconsistent with accepted standards, the principal author submitted a resolution to the Illinois State Medical Society (ISMS) in an attempt to encourage consistency in institutional policies on the determination of BD/DNC across the state. ISMS ultimately approved a resolution on this topic, but it has some shortcomings, so its impact is unclear. Nonetheless, other neuroscience clinicians are encouraged to engage with their state medical societies to advocate for uniformity in the determination of BD/DNC.

PURPOSE:The term "brainstem death" is ambiguous; it can be used to refer either exclusively to loss of function of the brainstem or loss of function of the whole brain. We aimed to establish the term's intended meaning in national protocols for the determination of brain death/death by neurologic criteria (BD/DNC) from around the world. METHODS:Of 78 unique international protocols on determination of BD/DNC, we identified eight that referred exclusively to loss of function of the brainstem in the definition of death. Each protocol was reviewed to ascertain whether it 1) required assessment for loss of function of the whole brain, 2) required assessment only for loss of function of the brainstem, or 3) was ambiguous about whether loss of function of the higher brain was required to declare DNC. RESULTS:Of the eight protocols, two (25%) required assessment for loss of function of the whole brain, three (37.5%) only required assessment for loss of function of the brainstem, and three (37.5%) were ambiguous about whether loss of function of the higher brain was required to declare death. The overall agreement between raters was 94% (κ = 0.91). CONCLUSIONS:There is international variability in the intended meaning of the terms "brainstem death" and "whole brain death" resulting in ambiguity and potentially inaccurate or inconsistent diagnosis. Regardless of the nomenclature, we advocate for national protocols to be clear regarding any requirement for ancillary testing in cases of primary infratentorial brain injury who may fulfill clinical criteria for BD/DNC.

This 2023 Clinical Practice Guideline provides the biomedical definition of death based on permanent cessation of brain function that applies to all persons, as well as recommendations for death determination by circulatory criteria for potential organ donors and death determination by neurologic criteria for all mechanically ventilated patients regardless of organ donation potential. This Guideline is endorsed by the Canadian Critical Care Society, the Canadian Medical Association, the Canadian Association of Critical Care Nurses, Canadian Anesthesiologists' Society, the Canadian Neurological Sciences Federation (representing the Canadian Neurological Society, Canadian Neurosurgical Society, Canadian Society of Clinical Neurophysiologists, Canadian Association of Child Neurology, Canadian Society of Neuroradiology, and Canadian Stroke Consortium), Canadian Blood Services, the Canadian Donation and Transplantation Research Program, the Canadian Association of Emergency Physicians, the Nurse Practitioners Association of Canada, and the Canadian Cardiovascular Critical Care Society.

Interest in disorders of consciousness (DoC) has grown substantially over the past decade and has illuminated the importance of improving understanding of DoC biology; care needs (use of monitoring, performance of interventions, and provision of emotional support); treatment options to promote recovery; and outcome prediction. Exploration of these topics requires awareness of numerous ethics considerations related to rights and resources. The Curing Coma Campaign Ethics Working Group used its expertise in neurocritical care, neuropalliative care, neuroethics, neuroscience, philosophy, and research to formulate an informal review of ethics considerations along the continuum of research involving persons with DoC related to the following: (1) study design; (2) comparison of risks versus benefits; (3) selection of inclusion and exclusion criteria; (4) screening, recruitment, and enrollment; (5) consent; (6) data protection; (7) disclosure of results to surrogates and/or legally authorized representatives; (8) translation of research into practice; (9) identification and management of conflicts of interest; (10) equity and resource availability; and (11) inclusion of minors with DoC in research. Awareness of these ethics considerations when planning and performing research involving persons with DoC will ensure that the participant rights are respected while maximizing the impact and meaningfulness of the research, interpretation of outcomes, and communication of results.

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2023. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2023 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from https://link.springer.com/bookseries/8901 .