A Biophilosophical Approach to the Determination of Brain Death.

Technical and clinical developments have raised challenging questions about the concept and practice of brain death, culminating in recent calls for revision of the Uniform Determination of Death Act (UDDA), which established a whole brain standard for neurologic death. Proposed changes range from abandoning the concept of brain death altogether to suggesting that current clinical practice simply should be codified as the legal standard for determining death by neurologic criteria (even while acknowledging that significant functions of the whole brain might persist). We propose a middle ground, clarifying why whole brain death is a conceptually sound standard for declaring death, and offering procedural suggestions for increasing certainty that this standard has been met. Our approach recognizes that whole brain death is a functional, not merely anatomic, determination, and incorporates an understanding of the difficulties inherent in making empirical judgments in medicine. We conclude that whole brain death is the most defensible standard for determining neurologic death-philosophically, biologically, and socially-and ought to be maintained.

Organismal Superposition Problem and Nihilist Challenge in the Definition of Death.

According to the mainstream bioethical stance, death constitutes the termination of an organism. This essay argues that such an understanding of death is inappropriate in the usual context of determining death, since it also has a social bearing. There are two reasons to justify this argument. First, the mainstream bioethical definition generates an organismal superposition challenge, according to which a given patient in a single physiological state might be both alive and dead, like Schrödinger's cat. Therefore, there is no clear answer as to whether organ retrieval from a brain-dead patient is an act of killing or not. Second, when combined with the dead donor rule, the mainstream position in the definition of death might lead to ethically unacceptable verdicts, since there is a discrepancy between terminating an organism and depriving someone of moral status.

Taking the pulse of brain death: A meta-analysis of the natural history of brain death with somatic support.

BACKGROUND AND PURPOSE: The conceptualization of brain death (BD) was pivotal in the shaping of judicial and medical practices. Nonetheless, media reports of alleged recovery from BD reinforced the criticism that this construct is a self-fulfilling prophecy (by treatment withdrawal or organ donation). We meta-analyzed the natural history of BD when somatic support (SS) is maintained. METHODS: Publications on BD were eligible if the following were reported: aggregated data on its natural history with SS; and patient-level data that allowed censoring at the time of treatment withdrawal or organ donation. Endpoints were as follows: rate of somatic expiration after BD with SS; BD misdiagnosis, including "functionally brain-dead" patients (FBD; i.e. after the pronouncement of brain-death, ≥1 findings were incongruent with guidelines for its diagnosis, albeit the lethal prognosis was not altered); and length and predictors of somatic survival. RESULTS: Forty-seven articles were selected (1610 patients, years: 1969-2021). In BD patients with SS, median age was 32.9 years (range = newborn-85 years). Somatic expiration followed BD in 99.9% (95% confidence interval = 89.8-100). Mean somatic survival was 8.0 days (range = 1.6 h-19.5 years). Only age at BD diagnosis was an independent predictor of somatic survival length (coefficient = -11.8, SE = 4, p < 0.01). Nine BD misdiagnoses were detected; eight were FBD, and one newborn fully recovered. No patient ever recovered from chronic BD (≥1 week somatic survival). CONCLUSIONS: BD diagnosis is reliable. Diagnostic criteria should be fine-tuned to avoid the small incidence of misdiagnosis, which nonetheless does not alter the prognosis of FBD patients. Age at BD diagnosis is inversely proportional to somatic survival.

New developments in guidelines for brain death/death by neurological criteria.

The declaration of brain death (BD), or death by neurological criteria (DNC), is medically and legally accepted throughout much of the world. However, inconsistencies in national and international policies have prompted efforts to harmonize practice and central concepts, both between and within countries. The World Brain Death Project was published in 2020, followed by notable revisions to the Canadian and US guidelines in 2023. The mission of these initiatives was to ensure accurate and conservative determination of BD/DNC, as false-positive determinations could have major negative implications for the medical field and the public's trust in our ability to accurately declare death. In this Review, we review the changes that were introduced in the 2023 US BD/DNC guidelines and consider how these guidelines compare with those formulated in Canada and elsewhere in the world. We address controversies in BD/DNC determination, including neuroendocrine function, consent and accommodation of objections, summarize the legal status of BD/DNC internationally and discuss areas for further BD/DNC research.

Outcome analysis of brain-death referral to NOD-Lb: A retrospective chart review of a single hospital experience over 3 years.

BACKGROUND: Organ donation shortage and in particular organ procurement is an international concern as the gap between the number of donors and recipients is steadily growing. Organ procurement is a chain of steps with donor identification and referral (ID&R) as the very first link in this chain. Failure of this step hinders the progress in the organ transplantation program. OBJECTIVES: Our study was conducted to evaluate and highlight the gap between the national system and the practice at the identification and referral (ID&R) step of the organ procurement chain in a single tertiary-care academic health center in Beirut: the Lebanese American University Medical Center-Rizk Hospital (LAUMC-RH), and to appraise the literature for challenges at this step and for possible interventions for improvement based on the international experience. MATERIALS AND METHODS: This retrospective study was a descriptive case series of ICU and ED deceased patients at a single tertiary-care university hospital in Beirut. Patients' characteristics were collected from medical records for all patients who died between 2017 and 2019 while in the ICU or the ED and shared with the National Organization for Organ and Tissue Donation and Transplantation (NOD-Lb), for each subject separately, to decide on the donor status. All data collected from the patient cohort was analyzed using R version 3.6.1. Wilcoxon signed-rank test, chi-squared, and fisher-exact tests were used to compare differences in clinical characteristics in terms of donor status when appropriate. RESULTS: This study served as 3 years audit of a single hospital experience, and it demonstrates failure to make any referrals to NOD-Lb and zero actual organ and tissue donations over the study period. The review of 295 deceased subjects' charts demonstrates 295 missed alerts to NOD-Lb and the overall missing of 5 organ and tissue donors and 24 cornea donors assuming the organ procurement chain of steps will continue uninterrupted after ID&R. CONCLUSION: The data gathered suggests the presence of an inefficient identification and referral system that is translated into a complete failure of reporting to NOD-Lb from LAUMC-RH. A systematic evidence-based approach to evaluate for the most cost-effective intervention to increase identification and referral rates is needed with a serious effort to examine and account for any inefficient implantation.

The Fundamental Concept of Death-Controversies and Clinical Relevance: The UDDA Revision Series.

When the Uniform Law Commission (ULC) was recently in the process of revising the Uniform Determination of Death Act (UDDA), Neurology® ran a series of debates over certain controversial issues being deliberated. Omitted was a debate over the fundamental concept underlying brain death. In his introductory article, Bernat offered reasons for this omission: "It is not directly relevant to practicing neurologists who largely accept brain death, do not question its conceptual basis, …." In this article I argue the opposite: the fundamental concept of death is highly relevant to the clinical criteria and tests used to diagnose it. Moreover, most neurologists in fact disagree with the conceptual basis articulated by Bernat. Basically, there are 3 competing concepts of death: (1) biological: cessation of the integrative unity of the organism as a whole (endorsed by Bernat and the 1981 President's Commission), (2) psychological: cessation of the person, equated with a self-conscious mind (endorsed by half of neurologists), and (3) the vital work concept proposed by the 2008 President's Council on Bioethics. The first actually corresponds to a circulatory, not a neurologic, criterion. The second corresponds to a "higher brain" criterion. The third corresponds loosely to the UK's "brainstem death" criterion. In terms of the biological concept, current diagnostic guidelines entail a high rate of false-positive declarations of death, whereas in terms of the psychological concept, the same guidelines entail a high rate of false-negative declarations. Brainstem reflexes have nothing to do with any death concept (their role is putatively to guarantee irreversibility). By shining a spotlight on the deficiencies of the UDDA through attempting to revise it, the ULC may have unwittingly opened a Pandora's box of fresh scrutiny of the concept of death underlying the neurologic criterion-particularly on the part of state legislatures with irreconcilably opposed worldviews.

Computed tomography angiography in the diagnosis of brain death: Implementation and results in Germany.

BACKGROUND: Computed tomography angiography (CTA) has been investigated as a confirmatory study (CS) for the diagnosis of brain death (BD). International consensus regarding its use, study parameters, and evaluation criteria is lacking. In the German BD guideline, a CTA protocol was first introduced in 2015. METHODS: The authors obtained a comprehensive dataset of all BD examinations in adults from the German organ procurement organization to investigate implementation, results, and impact of CTA on BD determination during the first 4 years. RESULTS: In 5152 patients with clinically absent brain function, 1272 CTA were reported by 676 hospitals. Use of CTA increased from 17.2% of patients in the first year to 29.7% in the final year. CTA replaced other CS such as electroencephalography without increasing overall CS frequency. Technical failure was rare (0.9%); 89.3% of studies were positive. Negative results (9.8%) were more frequent with secondary brain injury, longer duration of the clinical BD syndrome, or unreliable clinical assessment. Median time to diagnosis was longer with CTA (2.6 h) versus other CS (1.6 h). CTA had no differential impact on the rate of confirmed BD and did not improve access of small hospitals to CS for BD determination. CONCLUSIONS: CTA expands the range of available CS for the diagnosis of BD in adults. Real-world evidence from a large cohort confirms usability of the German CTA protocol within the guideline-specified context.

Author Response: Challenges to Brain Death in Revising the Uniform Determination of Death Act: The UDDA Revision Series.

I thank Dr. Machado for his comments about my article summarizing the recent work of the US Uniform Law Commission to revise the Uniform Determination of Death Act.1.

Reader Response: Challenges to Brain Death in Revising the Uniform Determination of Death Act: The UDDA Revision Series.

Bernat1 discussed that BD/DNC acceptance has always generated adversaries who, for conceptual or religious reasons, castoff it as human death. Therefore, to provide a conceptual framework of BD/DNC is essential to revise the UDDA.

Editors' Note: Challenges to Brain Death in Revising the Uniform Determination of Death Act: The UDDA Revision Series.

Despite decades of striving to simplify the diagnosis of human death according to irreversible cessation of function of a single organ system-the brain-we are relentlessly plagued by disagreement between experts spanning disciplines from medicine to philosophy. Dr. Bernat summarizes the current state of this controversy in their narrative summary, recently published in Neurology. In this review, the first of a planned series on the Uniform Determination of Death Act (UDDA) and brain death determination in Neurology, Dr. Bernat appraises the current criteria for determining brain death and highlights the need for careful revision to the UDDA. Is death determined by irreversible loss of function of the brain-as-a-whole or loss of function of the whole brain? And how does one define irreversible brain dysfunction? With the upcoming revisions to this statute by the US Uniform Law Commission (ULC), we hope to find more answers than new questions, although both are likely to be a consequence of this update. In response to the article, Dr. Machado proposes death be defined by irreversible failure of the 2 elements of consciousness-arousal and awareness. Furthermore, Dr. Machado challenges the notion of biological death and emphasizes the value of specific testing depending on the region of brain injury, with ancillary (neurophysiologic) testing in patients with posterior fossa lesions. Dr. Bernat comments that the objective of the ULC is not to disentangle the controversy of defining death, which may be subjective-e.g., influenced by personal beliefs, religious background, and interpretation of diagnostic testing-but instead to provide objective criteria for determining death. The revised UDDA may provide clarity in medical decision-making; however, it may not reconcile our division over ontology.

The 2023 American Academy of Neurology, American Academy of Pediatrics, Child Neurology Society, and Society of Critical Care Medicine Pediatric and Adult Brain Death/Death by Neurologic Criteria Determination Consensus Guidelines: What the Critical Care Team Needs to Know.

Guidelines for brain death/death by neurologic criteria (BD/DNC) determination were revised to provide a consistent and updated approach to BD/DNC evaluation across all ages by the American Academy of Neurology, American Academy of Pediatrics, Child Neurology Society, and Society of Critical Care Medicine. This article is intended to complement the guidelines and highlight aspects relevant to the critical care community; the actual guidelines should be used to update hospital protocols and dictate clinical practice. Because BD/DNC evaluations are conducted in the ICU, it is essential for members of the critical care community to familiarize themselves with these guidelines. The fundamental concept of BD/DNC has not changed; BD/DNC is permanent loss of function of the brain as a whole, including the brain stem, resulting in coma, brainstem areflexia, and apnea in the setting of an adequate stimulus. The BD/DNC evaluation requires a sufficient observation period to ensure there is no chance of recovery, followed by exclusion of potentially confounding conditions like hypothermia, hypotension, severe metabolic disturbances, or medication effects. Specific guidance is provided for patients who were treated with therapeutic hypothermia or medical or surgical interventions to manage intracranial hypertension. The guidelines outline a structured and meticulous neurologic examination and detail the responses consistent with BD/DNC. A protocol is provided for how to safely perform apnea testing, including modifications needed for patients on extracorporeal membrane oxygenation. Controversial issues such as consent, BD/DNC evaluation in pregnancy, preservation of neuroendocrine function, and primary posterior fossa injuries are addressed. The ultimate goal is to ensure a consistent and accurate approach to BD/DNC evaluation in patients of all ages, fostering public trust in the medical community's ability to determine death. By adhering to these guidelines, critical care clinicians can confidently navigate the challenging aspects of BD/DNC determination.