A brain-based definition of death and criteria for its determination after arrest of circulation or neurologic function in Canada: a 2023 clinical practice guideline

Beyond the Final Heartbeat: Neurological Perspectives on Normothermic Regional Perfusion for Organ Donation after Circulatory Death

Normothermic regional perfusion (NRP) has recently been used to augment organ donation after circulatory death (DCD) to improve the quantity and quality of transplantable organs. In DCD-NRP, after withdrawal of life-sustaining therapies and cardiopulmonary arrest, patients are cannulated onto extracorporeal membrane oxygenation to reestablish blood flow to targeted organs including the heart. During this process, aortic arch vessels are ligated to restrict cerebral blood flow. We review ethical challenges including whether the brain is sufficiently reperfused through collateral circulation to allow reemergence of consciousness or pain perception, whether resumption of cardiac activity nullifies the patient's prior death determination, and whether specific authorization for DCD-NRP is required. ANN NEUROL 2024;95:1035-1039.

Knowledge gaps in heart and lung donation after the circulatory determination of death: Report of a workshop of the National Heart, Lung, and Blood Institute

In a workshop sponsored by the U.S. National Heart, Lung, and Blood Institute, experts identified current knowledge gaps and research opportunities in the scientific, conceptual, and ethical understanding of organ donation after the circulatory determination of death and its technologies. To minimize organ injury from warm ischemia and produce better recipient outcomes, innovative techniques to perfuse and oxygenate organs postmortem in situ, such as thoracoabdominal normothermic regional perfusion, are being implemented in several medical centers in the US and elsewhere. These technologies have improved organ outcomes but have raised ethical and legal questions. Re-establishing donor circulation postmortem can be viewed as invalidating the condition of permanent cessation of circulation on which the earlier death determination was made and clamping arch vessels to exclude brain circulation can be viewed as inducing brain death. Alternatively, TA-NRP can be viewed as localized in-situ organ perfusion, not whole-body resuscitation, that does not invalidate death determination. Further scientific, conceptual, and ethical studies, such as those identified in this workshop, can inform and help resolve controversies raised by this practice.

The Unified Brain-Based Determination of Death Conceptually Justifies Death Determination in DCDD and NRP Protocols

Organ donation after the circulatory determination of death requires the permanent cessation of circulation while organ donation after the brain determination of death requires the irreversible cessation of brain functions. The unified brain-based determination of death connects the brain and circulatory death criteria for circulatory death determination in organ donation as follows: permanent cessation of systemic circulation causes permanent cessation of brain circulation which causes permanent cessation of brain perfusion which causes permanent cessation of brain function. The relevant circulation that must cease in circulatory death determination is that to the brain. Eliminating brain circulation from the donor ECMO organ perfusion circuit in thoracoabdominal NRP protocols satisfies the unified brain-based determination of death but only if the complete cessation of brain circulation can be proved. Despite its medical and physiologic rationale, the unified brain-based determination of death remains inconsistent with the Uniform Determination of Death Act.

Sowing "seeds of trust": How trust in normothermic regional perfusion is built in a continuum of care

Normothermic regional perfusion (NRP) is a promising technology to improve organ transplantation outcomes by reversing ischemic injury caused by controlled donation after circulatory determination of death. However, it has not yet been implemented in Canada due to ethical questions. These issues must be resolved to preserve public trust in organ donation and transplantation. This qualitative, constructivist grounded theory study sought to understand how those most impacted by NRP perceived the ethical implications. We interviewed 29 participants across stakeholder groups of donor families, organ recipients, donation and transplantation system leaders and care providers. The interview protocol included a short presentation about the purpose of NRP and procedures in abdomen versus chest and abdomen NRP, followed by questions probing potential violations to the dead donor rule and concerns regarding brain reperfusion. The results present a grounded theory placing NRP within a trust-building continuum of care for the donor, their family, and organ recipients. Stakeholders consistently described both forms of NRP as an ethical intervention, but their rationales were predicated on assumptions that neurological criteria for death had been met following circulatory death determination. Empirical validation of these assumptions will help ground the implementation of NRP in a trust-preserving way.

Transcranial Doppler and Color-Coded Doppler Use for Brain Death Determination in Adult Patients: A Pictorial Essay

Transcranial Doppler (TCD) is a repeatable, at-the-bedside, helpful tool for confirming cerebral circulatory arrest (CCA). Despite its variable accuracy, TCD is increasingly used during brain death determination, and it is considered among the optional ancillary tests in several countries. Among its limitations, the need for skilled operators with appropriate knowledge of typical CCA patterns and the lack of adequate acoustic bone windows for intracranial arteries assessment are critical. The purpose of this review is to describe how to evaluate cerebral circulatory arrest in the intensive care unit with TCD and transcranial duplex color-coded doppler (TCCD).

Organ Donation in Canadian PICUs: A Cross-Sectional Survey, 2021-2022

OBJECTIVES

To understand contemporary pediatric organ donation programs in Canadian PICUs, including: policies and practices, data collection and reporting, and system and process barriers.

DESIGN

A cross-sectional survey carried out 2021-2022.

SETTING

Canadian PICUs affiliated with a donor physician network.

SUBJECTS

Pediatric intensivists identified as the donation program lead, or most knowledgeable about donation for their institution.

MEASUREMENTS AND MAIN RESULTS

A 19-item survey was developed through collaboration with stakeholders from the organ donation and transplantation community within Canada. Domains and items were generated and reduced iteratively during an in-person workshop. Pretesting and pilot testing were completed to ensure readability, flow, clinical sensibility, and construct validity. Fifteen of 16 (94%) invited Canadian PICUs from seven provinces completed the survey representing 88% (15/18) of all noncardiac Canadian PICUs. Surveys were completed between June 2021 and September 2022. All units support donation after death by neurologic criteria (DNC); 14 of 15 indicated donation policies were in place and 1 of 15 indicated no policy but the ability to facilitate donation. Thirteen of 15 units (87%) support donation after death by circulatory criteria (DCC) with policies in place, with 11 of 13 of these indicating routine support of donation opportunities. The majority (13/15) of units identified a donation champion. Of the 16 identified champions across these centers, 13 were physicians and were registered nurses or nurse practitioners. Eight of 13 units (62%) with donation champions had positions supported financially, of which 5 units came from the Organ Donation Organization and the other 3 came from the provincial health authority. Finally, only 3 of 15 PICU donation programs have a pediatric donation committee with family involvement. Variability exists in identification (including determination of death practices), referral, and approach for donation between units.

CONCLUSIONS

Although all Canadian PICUs support donation after DNC donation, and most support donation after DCC, variability exists in the identification, referral, and approach of potential donors. There is a notable lack of family involvement in pediatric donation programs. There are many opportunities for standardization of PICU donation programs which may result in improved rates of pediatric organ donation in Canada.

Advancing the Scientific Basis for Determining Death in Controlled Organ Donation After Circulatory Determination of Death

In controlled organ donation after circulatory determination of death (cDCDD), accurate and timely death determination is critical, yet knowledge gaps persist. Further research to improve the science of defining and determining death by circulatory criteria is therefore warranted. In a workshop sponsored by the National Heart, Lung, and Blood Institute, experts identified research opportunities pertaining to scientific, conceptual, and ethical understandings of DCDD and associated technologies. This article identifies a research strategy to inform the biomedical definition of death, the criteria for its determination, and circulatory death determination in cDCDD. Highlighting knowledge gaps, we propose that further research is needed to inform the observation period following cessation of circulation in pediatric and neonatal populations, the temporal relationship between the cessation of brain and circulatory function after the withdrawal of life-sustaining measures in all patient populations, and the minimal pulse pressures that sustain brain blood flow, perfusion, activity, and function. Additionally, accurate predictive tools to estimate time to asystole following the withdrawal of treatment and alternative monitoring modalities to establish the cessation of circulatory, brainstem, and brain function are needed. The physiologic and conceptual implications of postmortem interventions that resume circulation in cDCDD donors likewise demand attention to inform organ recovery practices. Finally, because jurisdictionally variable definitions of death and the criteria for its determination may impede collaborative research efforts, further work is required to achieve consensus on the physiologic and conceptual rationale for defining and determining death after circulatory arrest.

An Update on Brain Death/Death by Neurologic Criteria since the World Brain Death Project

The World Brain Death Project (WBDP) is a 2020 international consensus statement that provides historical background and recommendations on brain death/death by neurologic criteria (BD/DNC) determination. It addresses 13 topics including: (1) worldwide variance in BD/DNC, (2) the science of BD/DNC, (3) the concept of BD/DNC, (4) minimum clinical criteria for BD/DNC determination, (5) beyond minimum clinical BD/DNC determination, (6) pediatric and neonatal BD/DNC determination, (7) BD/DNC determination in patients on ECMO, (8) BD/DNC determination after treatment with targeted temperature management, (9) BD/DNC documentation, (10) qualification for and education on BD/DNC determination, (11) somatic support after BD/DNC for organ donation and other special circumstances, (12) religion and BD/DNC: managing requests to forego a BD/DNC evaluation or continue somatic support after BD/DNC, and (13) BD/DNC and the law. This review summarizes the WBDP content on each of these topics and highlights relevant work published from 2020 to 2023, including both the 192 citing publications and other publications on BD/DNC. Finally, it reviews questions for future research related to BD/DNC and emphasizes the need for national efforts to ensure the minimum standards for BD/DNC determination described in the WBDP are included in national BD/DNC guidelines and due consideration is given to the recommendations about social and legal aspects of BD/DNC determination.

Beliefs of physician directors on the management of devastating brain injuries at the Canadian emergency department and intensive care unit interface: a national site-level survey

PURPOSE

Insufficient evidence-based recommendations to guide care for patients with devastating brain injuries (DBIs) leave patients vulnerable to inconsistent practice at the emergency department (ED) and intensive care unit (ICU) interface. We sought to characterize the beliefs of Canadian emergency medicine (EM) and critical care medicine (CCM) physician site directors regarding current management practices for patients with DBI.

METHODS

We conducted a cross-sectional survey of EM and CCM physician directors of adult EDs and ICUs across Canada (December 2022 to March 2023). Our primary outcome was the proportion of respondents who manage (or consult on) patients with DBI in the ED. We conducted subgroup analyses to compare beliefs of EM and CCM physicians.

RESULTS

Of 303 eligible respondents, we received 98 (32%) completed surveys (EM physician directors, 46; CCM physician directors, 52). Most physician directors reported participating in the decision to withdraw life-sustaining measures (WLSM) for patients with DBI in the ED (80%, n = 78), but 63% of these (n = 62) said this was infrequent. Physician directors reported that existing neuroprognostication methods are rarely sufficient to support WLSM in the ED (49%, n = 48) and believed that an ICU stay is required to improve confidence (99%, n = 97). Most (96%, n = 94) felt that providing caregiver visitation time prior to WLSM was a valid reason for ICU admission.

CONCLUSION

In our survey of Canadian EM and CCM physician directors, 80% participated in WLSM in the ED for patients with DBI. Despite this, most supported ICU admission to optimize neuroprognostication and patient-centred end-of-life care, including organ donation.

Moving Boundaries for Improving Organ Transplant Availability

This brief overview is designed to address the options for increasing organ transplant rates to between 100 and 120 transplanted organs per million population globally. The focus of this review is the data produced through the World Health Organization's Global Observatory on Donation and Transplantation, with consideration for the issues that different countries need to address to achieve higher transplant rates. Without both optimized living donation and optimized deceased donation, rates of transplant are not sufficient to provide for a level of self-dependency for transplant therapy. Deceased donation comprises both donation from donors declared dead after cessation of all functions of the brain and donors declared dead from irreversible cessation of circulation of the blood. The preservation strategies that hold the greatest chance of increasing the utility of marginal and older donors involve normothermic circulation to prevent ischemic damage and potentially restore function of damaged organs. Normothermic in situ perfusion of abdominal organs has demonstrated utility, and consideration must be given to normothermic perfusion of the thoracic organs to improve heart and lung transplants, but this may challenge the legal definitions of death. Each nation must endeavor to increase organ donation capacity across the spectrum of donor types and must address the opportunities that normothermic perfusion of organs at retrieval may offer to alleviate shortages of organs for transplant and provide selfdependency for the communities.

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.

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.

Computed Tomography Perfusion for the Diagnosis of Brain Death: A Technical Review

Timely diagnosis of brain death (BD) is critical as it prevents unethical and futile continuation of support of vital organ functions when the patient has passed. Furthermore, it helps with avoiding the unnecessary use of resources and provides early opportunity for precious organ donation. The diagnosis of BD is mainly based on careful neurological assessment of patients with an established underlying diagnosis of neurological catastrophe capable of causing BD.Ancillary testing, however, is tremendously helpful in situations when the presence of confounders prevents or delays comprehensive neurological assessment. Traditionally, four-vessel digital subtraction angiography and computed tomography angiography have been used for blood flow (BF) examinations of the brain. The lack of BF in the intracranial arteries constitutes conclusive evidence that the brain is dead. However, there is an apparent discrepancy between the BF and sufficient cerebral perfusion; several studies have shown that in 15% of patients with confirmed clinical diagnosis of BD, BF is still preserved. In these patients, cerebral perfusion is significantly impaired. Hence, measurement of cerebral perfusion rather than BF will provide a more precise assessment of the brain function.In this review article, we discuss a brief history of BD, our understanding of its complex pathophysiology, current Canadian guidelines for the clinical diagnosis of BD, and the ancillary tests-specifically CT perfusion of the brain that help us with the prompt and timely diagnosis of BD.

Personalism and boosting organ ResERVOirs: a consideration of euthanasia by removal of vital organs in the Canadian context

Canada's decriminalisation of assisted death has elicited significant ethical implications for the use of assisted death in healthcare contexts. Euthanasia by removal of vital organs (ERVO) is a theoretical extension of medically assisted death with an increased plausibility of implementation in light of the rapid expansion of assisted death eligibility laws and criteria in Canada. ERVO entails removing organs from a living patient under general anaesthesia as the mechanism of death. While ERVO is intended to maximise the viability of organs procured from the euthanised patient for donation to recipients, ending the lives of patient donors in this manner solely to benefit ill or dying recipient patients merits further ethical consideration. Specifically, the paper explores the application of personalist bioethics in determining whether the means of procuring organs through assisted death justifies the end of improving the lives of those who would benefit from receiving them. Further, by discussing the medical, social and ethical implications of ERVO, I will explicate a broader philosophical understanding of the influences of legalising assisted death on human dignity and conscience.

Differences in proximal and intimacy-related defense mechanisms among patients with cancer in different psychological stages of dying

Purpose

This study measured three of the psychological stages of dying in patients with cancer and explored the differences in proximal and intimacy-related defense mechanisms at each stage.

Patients and methods

A total of 220 cancer patients were recruited for this study; 168 patients met the inclusion criteria and were included in the data analysis. The participants were divided into three groups using the "Death Attitudes Questionnaire Revised" (1994) and then completed the Death-Thought Accessibility Test, Self-Control Questionnaire, Rumination Reflection Questionnaire, Attachment Type Test, Intimacy Test, External Control Test, and Positive and Negative Affect Scale.

Results

In the death avoidance stage, which represents a defense stage without cognitive processes, patients are in an irrational state with the highest level of self-control and the lowest level of external control; they tend to prefer close relationships with many people while experiencing high levels of fear and depression. In the bargaining stage, which represents a biased cognitive defense stage, the level of rationality increases, the level of fear and depression decreases, and patients tend to prefer relationships with many people that do not involve intimacy. In the neutral death acceptance stage, which represents a defense stage without cognitive bias, self-control is lowest, external control is highest, patients tend to prefer intimate relationships with a few people, and experience the lowest levels of fear and depression.

Conclusion

Three psychological stages of death exist in cancer patients, with differences in proximal and intimacy-related defense mechanisms in each stage. The findings have theoretical and practical implications for psychological interventions for cancer patients.

Consent to testing for brain death

Canada has recently published a new Clinical Practice Guideline on the diagnosis and management of brain death. It states that consent is not necessary to carry out the interventions required to make the diagnosis. A supporting article not only sets out the arguments for this but also contends that 'UK laws similarly carve out an exception, excusing clinicians from a prima facie duty to get consent'. This is supplemented by the claim that recent court decisions in the UK similarly confirm that consent is not required, referencing two judgements in Battersbee We disagree with the authors' interpretation of the law on consent in the UK and argue that there is nothing in Battersbee to support the conclusion that consent to testing is not necessary. Where there is a disagreement about testing for brain death in the UK, court authorisation is required.

Untangling a taxonomy of living from the science of the continuum of life

Medical innovation and technologic advances enrich daily living and occur within our normative worlds, that are socially constructed. These advances confront society with critical questions about the nature of human life, laying bare the inadequacies of extant norms and boundaries. Yet, society has been unable to develop consensus about when life ends. Scientific studies highlight that life is best characterized by continua without natural boundaries. Thus, scientific information alone cannot be employed to justify the socially constructed health categories required for setting norms and boundaries. An iterative process that integrates a broad range of non-scientific data with advancing scientific information is needed to facilitate consensus for updating social norms and boundaries. This can lead to a new taxonomy of living across the measurable continuum of life and align our normative worlds with the dizzying pace of medical innovation and advances in technologies transforming the world in which we live.

Dons d’organes et de tissus après décès dans le cadre de l’aide médicale à mourir : mise à jour 2023 du document d’orientation pour l’élaboration de politiques

Contexte:

Depuis la parution du document d’orientation de 2019 de la Société canadienne du sang (SCS) pour les dons d’organes et de tissus après décès dans le cadre de l’aide médicale à mourir (AMM), le gouvernement fédéral a apporté des amendements à sa loi sur l’AMM. La présente mise à jour s’adresse aux médecins, aux organismes de don d’organes, aux spécialistes des soins de fin de vie et de l’AMM et aux responsables des orientations politiques; on y explique les répercussions de ces amendements.

Méthodes:

La Société canadienne du sang a réuni un groupe de 63 spécialistes de divers domaines (soins intensifs, dons d’organes et de tissus, administration des services de santé, AMM, bioéthique, droit et recherche) pour faire le point sur ces changements à l’occasion de son Forum d’orientation sur le don d’organes et de tissus après décès dans le cadre de l’aide médicale à mourir. Deux personnes admissibles à l’AMM et 2 proches de personnes ayant fait un don d’organe après l’AMM y ont aussi participé. Dans le cadre de 3 réunions consécutives tenues en ligne entre juin 2021 et avril 2022, les personnes participant au Forum ont abordé divers sujets en grands et petits groupes. Les discussions ont été guidées par une revue documentaire publiée selon la méthodologie JBI. Nous avons utilisé une technique du groupe nominal adaptée pour rédiger les recommandations qui ont fait consensus. La gestion des intérêts concurrents s’est faite selon les principes du Guidelines International Network, un réseau international qui se consacre aux lignes directrices de pratique clinique.

Recommandations:

Même si bon nombre des recommandations du document d’orientation de 2019 demeurent pertinentes, la présente mise à jour a permis d’en actualiser 2 et d’en formuler 8 nouvelles dans les domaines suivants : aiguillage vers un organisme de don d’organes, consentement, dons dirigés et conditionnels, procédure d’AMM, détermination du décès, équipes soignantes et préparation de rapports.

Interprétation:

Les politiques et les pratiques en matière de don d’organes et de tissus après l’AMM au Canada doivent être conformes à la législation canadienne actuelle. La mise à jour de ce document d’orientation aidera les médecins à s’y retrouver parmi les enjeux médicaux, juridiques et éthiques inhérents à leur travail auprès de personnes qui souhaitent faire un don d’organes après l’AMM.

Postarrest Neuroprognostication: Practices and Opinions of Canadian Physicians

BACKGROUND

Objective, evidence-based neuroprognostication of postarrest patients is crucial to avoid inappropriate withdrawal of life-sustaining therapies or prolonged, invasive, and costly therapies that could perpetuate suffering when there is no chance of an acceptable recovery. Postarrest prognostication guidelines exist; however, guideline adherence and practice variability are unknown.

OBJECTIVE

To investigate Canadian practices and opinions regarding assessment of neurological prognosis in postarrest patients.

METHODS

An anonymous electronic survey was distributed to physicians who care for adult postarrest patients.

RESULTS

Of the 134 physicians who responded to the survey, 63% had no institutional protocols for neuroprognostication. While the use of targeted temperature management did not affect the timing of neuroprognostication, an increasing number of clinical findings suggestive of a poor prognosis affected the timing of when physicians were comfortable concluding patients had a poor prognosis. Variability existed in what factors clinicians' thought were confounders. Physicians identified bilaterally absent pupillary light reflexes (85%), bilaterally absent corneal reflexes (80%), and status myoclonus (75%) as useful in determining poor prognosis. Computed tomography, magnetic resonance imaging, and spot electroencephalography were the most useful and accessible tests. Somatosensory evoked potentials were useful, but logistically challenging. Serum biomarkers were unavailable at most centers. Most (79%) physicians agreed ≥2 definitive findings on neurologic exam, electrophysiologic tests, neuroimaging, and/or biomarkers are required to determine a poor prognosis with a high degree of certainty. Distress during the process of neuroprognostication was reported by 70% of physicians and 51% request a second opinion from an external expert.

CONCLUSION

Significant variability exists in post-cardiac arrest neuroprognostication practices among Canadian physicians.

When is a person dead? The Canadian public's understanding of death and death determination: a nationwide survey

PURPOSE

We aimed to describe the Canadian public's understanding and perception of how death is determined in Canada, their level of interest in learning about death and death determination, and their preferred strategies for informing the public.

METHODS

We conducted a nationwide cross-sectional survey of a representative sample of the Canadian public. The survey presented two scenarios of a man who met current criteria for neurologic death determination (scenario 1) and a man who met current criteria for circulatory death determination (scenario 2). Survey questions evaluated understanding of how death is determined, acceptance of death determination by neurologic and circulatory criteria, and interest and preferred strategies in learning more about the topic.

RESULTS

Among 2,000 respondents (50.8% women; n = 1,015), nearly 67.2% believed that the man in scenario 1 was dead (n = 1,344) and 81.2% (n = 1,623) believed that the man in scenario 2 was dead. Respondents who believed that the man was not dead or were unsure endorsed several factors that may increase their agreement with the determination of death, including requiring more information about how death was determined, seeing the results of brain imaging/tests, and a third doctor's opinion. Predictors of disbelief that the man in scenario 1 is dead were younger age, being uncomfortable with the topic of death, and subscribing to a religion. Predictors of disbelief that the man in scenario 2 is dead were younger age, residing in Quebec (compared with Ontario), having a high school education, and subscribing to a religion. Most respondents (63.3%) indicated interest in learning more about death and death determination. Most respondents preferred to receive information about death and death determination from their health care professional (50.9%) and written information provided by their health care professional (42.7%).

CONCLUSION

Among the Canadian public, the understanding of neurologic and circulatory death determination is variable. More uncertainty exists with death determination by neurologic criteria than with circulatory criteria. Nevertheless, there is a high level of general interest in learning more about how death is determined in Canada. These findings provide important opportunities for further public engagement.

Brain-based arterial pulse pressure threshold for death determination: a systematic review

PURPOSE

There is lack of consensus regarding the minimum arterial pulse pressure required for confirming permanent cessation of circulation for death determination by circulatory criteria in organ donors. We assessed direct and indirect evidence supporting whether one should use an arterial pulse pressure of 0 mm Hg vs more than 0 (5, 10, 20, 40) mm Hg to confirm permanent cessation of circulation.

SOURCE

We conducted this systematic review as part of a larger project to develop a clinical practice guideline for death determination by circulatory or neurologic criteria. We systematically searched Ovid MEDLINE, Ovid Embase, Cochrane Central Register of Controlled Trials (CENTRAL) via the Cochrane Library, and Web of Science for articles published from inception until August 2021. We included all types of peer-reviewed original research publications related to arterial pulse pressure as monitored by an indwelling arterial pressure transducer around circulatory arrest or determination of death with either direct context-specific (organ donation) or indirect (outside of organ donation context) data.

PRINCIPAL FINDINGS

A total of 3,289 abstracts were identified and screened for eligibility. Fourteen studies were included; three from personal libraries. Five studies were of sufficient quality for inclusion in the evidence profile for the clinical practice guideline. One study measured cessation of cortical scalp electroencephalogram (EEG) activity after withdrawal of life-sustaining measures and showed that EEG activity fell below 2 μV when the pulse pressure reached 8 mm Hg. This indirect evidence suggests there is a possibility of persistent cerebral activity at arterial pulse pressures > 5 mm Hg.

CONCLUSION

Indirect evidence suggests that clinicians may incorrectly diagnose death by circulatory criteria if they apply any arterial pulse pressure threshold of greater than 5 mm Hg. Moreover, there is insufficient evidence to determine that any pulse pressure threshold greater than 0 and less than 5 can safely determine circulatory death.

STUDY REGISTRATION

PROSPERO (CRD42021275763); first submitted 28 August 2021.

Death determination by neurologic criteria-what do families understand?

PURPOSE

Currently, there is little empirical data on family understanding about brain death and death determination. The purpose of this study was to describe family members' (FMs') understanding of brain death and the process of determining death in the context of organ donation in Canadian intensive care units (ICUs).

METHODS

We conducted a qualitative study using semistructured, in-depth interviews with FMs who were asked to make an organ donation decision on behalf of adult or pediatric patients with death determination by neurologic criteria (DNC) in Canadian ICUs.

RESULTS

From interviews with 179 FMs, six main themes emerged: 1) state of mind, 2) communication, 3) DNC may be counterintuitive, 4) preparation for the DNC clinical assessment, 5) DNC clinical assessment, and 6) time of death. Recommendations on how clinicians can help FMs to understand and accept DNC through communication at key moments were described including preparing FMs for death determination, allowing FMs to be present, and explaining the legal time of death, combined with multimodal strategies. For many FMs, understanding of DNC unfolded over time, facilitated with repeated encounters and explanation, rather than during a single meeting.

CONCLUSION

Family members' understanding of brain death and death determination represented a journey that they reported in sequential meeting with health care providers, most notably physicians. Modifiable factors to improve communication and bereavement outcomes during DNC include attention to the state of mind of the family, pacing and repeating discussions according to families' expressed understanding, and preparing and inviting families to be present for the clinical determination including apnea testing. We have provided family-generated recommendations that are pragmatic and can be easily implemented.

Consent for determination of death by neurologic criteria in Canada: an analysis of legal and ethical authorities, and consensus-based working group recommendations

This article addresses the following question: should physicians obtain consent from the patient (through an advance directive) or their surrogate decision-maker to perform the assessments, evaluations, or tests necessary to determine whether death has occurred according to neurologic criteria? While legal bodies have not yet provided a definitive answer, significant legal and ethical authority holds that clinicians are not required to obtain family consent before making a death determination by neurologic criteria. There is a near consensus among available professional guidelines, statutes, and court decisions. Moreover, prevailing practice does not require consent to test for brain death. While arguments for requiring consent have some validity, proponents cannot surmount weightier considerations against imposing a consent requirement. Nevertheless, even though clinicians and hospitals may not be legally required to obtain consent, they should still notify families about their intent to determine death by neurologic criteria and offer temporary reasonable accommodations when feasible. This article was developed with the legal/ethics working group of the project, A Brain-Based Definition of Death and Criteria for its Determination After Arrest of Circulation or Neurologic Function in Canada developed in collaboration with the Canadian Critical Care Society, Canadian Blood Services, and the Canadian Medical Association. The article is meant to provide support and context for this project and is not intended to specifically advise physicians on legal risk, which in any event is likely jurisdiction dependent because of provincial or territorial variation in the laws. The article first reviews and analyzes ethical and legal authorities. It then offers consensus-based recommendations regarding consent for determination of death by neurologic criteria in Canada.

Rationale for revisions to the definition of death and criteria for its determination in Canada

Clarity regarding the biomedical definition of death and the criteria for its determination is critical to inform practices in clinical care, medical research, law, and organ donation. While best practices for death determination by neurologic criteria and circulatory criteria were previously outlined in Canadian medical guidelines, several issues have arisen to force their reappraisal. Ongoing scientific discovery, corresponding changes in medical practice, and legal and ethical challenges compel a comprehensive update. Accordingly, the A Brain-Based Definition of Death and Criteria for its Determination After Arrest of Neurologic or Circulatory Function in Canada project was undertaken to a develop a unified brain-based definition of death, and to establish criteria for its determination after devastating brain injury and/or circulatory arrest. Specifically, the project had three objectives: (1) to clarify that death is defined in terms of brain functions; (2) to clarify how a brain-based definition of death is articulated; and (3) to clarify the criteria for determining if the brain-based definition is met. The updated death determination guideline therefore defines death as the permanent cessation of brain function and describes corresponding circulatory and neurologic criteria to ascertain the permanent cessation of brain function. This article explores the challenges that prompted revisions to the biomedical definition of death and the criteria for its determination and outlines the rationales underpinning the project's three objectives. By clarifying that all death is defined in terms of brain function, the project seeks to align guidelines with contemporary medicolegal understandings of the biological basis of death.

Infratentorial brain injury and death by neurologic criteria in Canada: a narrative review

There are two anatomic formulations of death by neurologic criteria accepted worldwide: whole-brain death and brainstem death. As part of the Canadian Death Definition and Determination Project, we convened an expert working group and performed a narrative review of the literature. Infratentorial brain injury (IBI) with an unconfounded clinical assessment consistent with death by neurologic criteria represents a nonrecoverable injury. The clinical determination of death cannot distinguish between IBI and whole-brain cessation of function. Current clinical, functional, and neuroimaging assessments cannot reliably confirm the complete and permanent destruction of the brainstem. No patient with isolated brainstem death has been reported to recover consciousness and all patients have died. Studies suggest a significant majority of isolated brainstem death will evolve into whole-brain death, influenced by time/duration of somatic support and impacted by ventricular drainage and/or posterior fossa decompressive craniectomy. Acknowledging variability in intensive care unit (ICU) physician opinion on this matter, a majority of Canadian ICU physicians would perform ancillary testing for death determination by neurologic criteria in the context of IBI. There is currently no reliable ancillary test to confirm complete destruction of the brainstem; ancillary testing currently includes evaluation of both infratentorial and supratentorial flow. Acknowledging international variability in this regard, the existing evidence reviewed does not provide sufficient confidence that the clinical exam in IBI represents a complete and permanent destruction of the reticular activating system and thus the capacity for consciousness. On this basis, IBI consistent with clinical signs of death by neurologic criteria without significant supratentorial involvement does not fulfill criteria for death in Canada and ancillary testing is required.

Diagnostic test accuracy for cessation of circulation during death determination: a systematic review

PURPOSE

To synthesize the available evidence comparing noninvasive methods of measuring the cessation of circulation in patients who are potential organ donors undergoing death determination by circulatory criteria (DCC) with the current accepted standard of invasive arterial blood pressure (IAP) monitoring.

SOURCE

We searched (from inception until 27 April 2021) MEDLINE, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials. We screened citations and manuscripts independently and in duplicate for eligible studies that compared noninvasive methodologies assessing circulation in patients who were monitored around a period of cessation of circulation. We performed risk of bias assessment, data abstraction, and quality assessment using Grading of Recommendations, Assessment, Development, and Evaluation in duplicate and independently. We presented findings narratively.

PRINCIPAL FINDINGS

We included 21 eligible studies (N = 1,177 patients). Meta-analysis was not possible because of study heterogeneity. We identified low quality evidence from four indirect studies (n = 89) showing pulse palpation is less sensitive and specific than IAP (reported sensitivity range, 0.76-0.90; specificity, 0.41-0.79). Isoelectric electrocardiogram (ECG) had excellent specificity for death (two studies; 0% [0/510]), but likely increases the average time to death determination (moderate quality evidence). We are uncertain whether point-of-care ultrasound (POCUS) pulse check, cerebral near-infrared spectroscopy (NIRS), or POCUS cardiac motion assessment are accurate tests for the determination of circulatory cessation (very low-quality evidence).

CONCLUSION

There is insufficient evidence that ECG, POCUS pulse check, cerebral NIRS, or POCUS cardiac motion assessment are superior or equivalent to IAP for DCC in the setting of organ donation. Isoelectric ECG is specific but can increase the time needed to determine death. Point-of-care ultrasound techniques are emerging therapies with promising initial data but are limited by indirectness and imprecision.

STUDY REGISTRATION

PROSPERO (CRD42021258936); first submitted 16 June 2021.

Navigating disagreement and conflict in the context of a brain-based definition of death

In this paper, we discuss situations in which disagreement or conflict arises in the critical care setting in relation to the determination of death by neurologic criteria, including the removal of ventilation and other somatic support. Given the significance of declaring a person dead for all involved, an overarching goal is to resolve disagreement or conflict in ways that are respectful and, if possible, relationship preserving. We describe four different categories of reasons for these disagreements or conflicts: 1) grief, unexpected events, and needing time to process these events; 2) misunderstanding; 3) loss of trust; and 4) religious, spiritual, or philosophical differences. Relevant aspects of the critical care setting are also identified and discussed. We propose several strategies for navigating these situations, appreciating that these may be tailored for a given care context and that multiple strategies may be helpfully used. We recommend that health institutions develop policies that outline the process and steps involved in addressing situations where there is ongoing or escalating conflict. These policies should include input from a broad range of stakeholders, including patients and families, as part of their development and review.