The concept and practice of brain death

The conceptual injustice of the brain death standard

Family disputes over the diagnosis of brain death have caused much controversy in the bioethics literature over the conceptual validity of the brain death standard. Given the tenuous status of brain death as death, it is pragmatically fruitful to reframe intractable debates about the metaphysical nature of brain death as metalinguistic disputes about its conceptual deployment. This new framework leaves the metaphysical debate open and brings into focus the social functions that are served by deploying the concept of brain death. In doing so, it highlights the epistemic injustice of medicolegal authorities that force people to uniformly accept brain death as a diagnosis of death based on normative considerations of institutional interests, such as saving hospital resources and organ supplies, rather than empirical evidence of brain death as death, which is insufficient at best and nonexistent at worst. In light of this injustice, I propose the rejection of the uniform standard of brain death in favor of a choice-based system that respects families' individualized views of death.

Brain Death Confirmation by 18F-FDG PET/CT: A Case Series

OBJECTIVES

Brain death is a state of irreversible loss of brain function in the cortex and brainstem. Diagnosis of brain death is established by clinical assessments of cranial nerves and apnea tests. Different conditions can mimic brain death. In addition, confirmatory tests may be falsely positive in some cases. In this study, we aimed to evaluate the role of positron emission tomography-computed tomography scan with 2-deoxy-2[18F]fluoro-D-glucose (18F-FDG-PET/CT) as an ancillary test in diagnosing brain death.

MATERIALS AND METHODS

We analyzed 6 potential brain death donors for the confirmatory diagnosis of brain death using FDG-PET/CT. All 6 donors were brain dead by clinical criteria. All patients had electroencephalogram and brain computed tomography. Other than FDG-PET/CT, transcranial Doppler was performed in 1 patient, with other patients having no confirmatory ancillary imaging tests. Patients had nothing by mouth for 6 hours before imaging. Patients were supine in a semi-dark, noiseless, and odorless room with closed eyes. After 60 minutes of uptake,the brain PET/CT scan was performed with sequential time-of-flight-PET/CT (Discovery 690 PET/CT with 64 slices, GE Healthcare). The PET scan consisted of LYSO (Lu1.8Y0.2 SiO5) crystals with dimensions of 4.2 × 6.3 × 25 mm3. Three-dimension images were with scan duration of 10 minutes.

RESULTS

The PET scan confirmed brain death in 5 of the 6 cases. However, we ruled out brain death using PET/CT in a 3-year-old child, although all clinical tests confirmed brain death.

CONCLUSIONS

A PET scan illustrates a hollow skull phenomenon suggestive of brain death. It can be a powerful diagnostic tool to assess brain death.

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.

Public Understandings of the Definition and Determination of Death: A Scoping Review

Background.

Advances in medicine and technology that have made it possible to support, repair, or replace failing organs challenge commonly held notions of life and death. The objective of this review is to develop a comprehensive description of the current understandings of the public regarding the meaning/definition and determination of death.

Methods.

This scoping review was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews checklist. Online databases were used to identify articles published from 2003 to 2021. Two reviewers (S.S. and K.Z.) screened the articles using predefined inclusion and exclusion criteria, extracted data for specific content variables, and performed descriptive examination. Complementary searches of reference lists complemented the final study selection. A search strategy using vocabulary of the respective databases was created, and criteria for the inclusion and exclusion of the articles were established.

Results.

Seven thousand four hundred twenty-eight references were identified. Sixty were retained for analysis, with 4 additional references added from complementary searches. A data extraction instrument was developed to iteratively chart the results. A qualitative approach was conducted to thematically analyze the data. Themes included public understanding/attitudes toward death and determination of death (neurological determination and cardiocirculatory determination of death), death and organ donation, public trust and legal variability, and media impacts.

Conclusions.

This review provides a current and comprehensive overview of the literature related to the general public’s understanding and attitudes toward death and death determination and serves to highlight the gaps in this topic.

Diagnosing death 50 years after the Harvard brain death report

More than 50 years after the publication of the Harvard Committee Report that sought to define death according to whole-brain function criteria, this document continues to generate a diversity of opinions regarding how death should be defined. The various perspectives show that doubts linger regarding when brain death should be diagnosed, the criteria to pinpoint the occurrence of death, and the alignment of medical practices seeking to establish human death with these criteria. This study reviews and assesses three perspectives that have made significant contributions to the debate. Attention is also given to definitions of death that depart from the recommendations of the Harvard Report. Appraisals of various arguments lead to the conclusion that changes in the definition of death have resulted from advances in knowledge of human biology, medical technology and diagnostic techniques. A commentary is included on expediting the time of death with the view of organ donation.

Analysis of the reasons for nurses' confusion in relation to the concept of brain death from clinical and legal points of view

Background

Nurses in intensive care units (ICU) play a key role in taking care of brain dead patients and they are often in contact with such patients given the high rate of brain deaths. Consequently, they are in a challenging and stressful condition, which may be aggravated due to the need for increased organ donation, and this may also affect the quality of care provided for these patients.

Objective

This review analyzes the different studies on the concept of brain death from both medical and legal points of view. The aim of this study was to identify the challenges the nurses face with the perception of the concept of brain death and its effects on the care provided for the patients suffering from brain death, as well as organ donation.

Methods

This Narrative review study summarizes the information obtained from relevant literature through a targeted search of library texts and electronic resources including Science Direct, PubMed, Google Scholar, Scientific Information Database (SID), IranMedex, and Magiran databases during 2000–2017 in English and Persian, on the subject of interest by keywords such as brain death, organ donation, care, legal, regulations and nursing. Finally, a total of 44 relevant articles were reviewed.

Results

Nurses play an important role in taking care of brain dead patients; therefore, recognizing challenges can be the first step in taking accurate care of these patients and subsequently maintaining the organs’ health for transplants. Although there are clinical and legal uncertainties regarding the concept of brain death, nurses have an important effect on taking care of brain dead patients as well as the rate of organ donation.

Conclusion

Nurses in intensive care units should have a clear understanding of the concept of brain death in order to be able to take care of brain dead patients by avoiding psychological effects. In this regard, it is recommended that a comprehensive educational program be designed on the dimensions of brain death. Therefore, the nurses’ awareness of brain death and their ability to clarify this concept to the patients’ relatives would have a great effect on the decrease in the challenges and the stress imposed on the nurses. Also, there would be an increase in the quality of the care given to brain dead patients and even the rate of organ donation.

False-Positive Diagnosis of Brain Death Following the Pediatric Guidelines: Case Report and Discussion

A 2-year-old boy with severe head trauma was diagnosed brain dead according to the 2011 Pediatric Guidelines. Computed tomographic (CT) scan showed massive cerebral edema with herniation. Intracranial pressures were extremely high, with cerebral perfusion pressures around 0 for several hours. An apnea test was initially contraindicated; later, one had to be terminated due to oxygen desaturation when the Pco₂ had risen to 57.9 mm Hg. An electroencephalogram (EEG) was probably isoelectric but formally interpreted as equivocal. Tc-99m diethylene-triamine-pentaacetate (DTPA) scintigraphy showed no intracranial blood flow, so brain death was declared. Parents declined organ donation. A few minutes after withdrawal of support, the boy began to breathe spontaneously, so the ventilator was immediately reconnected and the death declaration rescinded. Two hours later, life support was again removed, this time for prognostic reasons; he did not breathe, and death was declared on circulatory-respiratory grounds. Implications regarding the specificity of the guidelines are discussed.

The Case for Reasonable Accommodation of Conscientious Objections to Declarations of Brain Death

Since its inception in 1968, the concept of whole-brain death has been contentious, and four decades on, controversy concerning the validity and coherence of whole-brain death continues unabated. Although whole-brain death is legally recognized and medically entrenched in the United States and elsewhere, there is reasonable disagreement among physicians, philosophers, and the public concerning whether brain death is really equivalent to death as it has been traditionally understood. A handful of states have acknowledged this plurality of viewpoints and enacted "conscience clauses" that require "reasonable accommodation" of religious and moral objections to the determination of death by neurological criteria. This paper argues for the universal adoption of "reasonable accommodation" policies using the New Jersey statute as a model, in light of both the ongoing controversy and the recent case of Jahi McMath, a child whose family raised religious objections to a declaration of brain death. Public policies that accommodate reasonable, divergent viewpoints concerning death provide a practical and compassionate way to resolve those conflicts that are the most urgent, painful, and difficult to reconcile.

Lived Experiences of Iranian Nurses Caring for Brain Death Organ Donor Patients: Caring as "Halo of Ambiguity and Doubt"

Background:

Brain death is a concept in which its criteria have been expressed as documentations in Harvard Committee of Brain Death. The various perceptions of caregiver nurses for brain death patients may have effect on the chance of converting potential donors into actual organ donors.

Objective:

The present study has been conducted in order to perceive the experiences of nurses in care-giving to the brain death of organ donor patients.

Methods:

This qualitative study was carried out by means of Heidegger’s hermeneutic phenomenology. Eight nurses who have been working in ICU were interviewed. The semi-structured interviews were recorded by a tape-recorder and the given texts were transcribed and the analyses were done by Van-Mannen methodology and (thematic) analysis.

Results:

One of the foremost themes extracted from this study included ‘Halo of ambiguity and doubt’ that comprised of two sub-themes of ‘having unreasonable hope’ and ‘Conservative acceptance of brain death’. The unreasonable hope included lack of trust (uncertainty) in diagnosis and verification of brain death, passing through denial wall, and avoidance from explicit and direct disclosure of brain death in patients’ family. In this investigation, the nurses were involved in a type of ambiguity and doubt in care-giving to the potentially brain death of organ donor patients, which were also evident in their interaction with patients’ family and for this reason, they did not definitely announce the brain death and so far they hoped for treatment of the given patient. Such confusion and hesitance both caused annoyance of nurses and strengthening the denial of patients’ family to be exposed to death.

Conclusion:

The results of this study reveal the fundamental perceived care-giving of brain death in organ donor patients and led to developing some strategies to improve care-giving and achievement in donation of the given organ and necessity for presentation of educational and supportive services for nurses might become more evident than ever.

East-West differences in perception of brain death. Review of history, current understandings, and directions for future research

The concept of brain death as equivalent to cardiopulmonary death was initially conceived following developments in neuroscience, critical care, and transplant technology. It is now a routine part of medicine in Western countries, including the United States. In contrast, Eastern countries have been reluctant to incorporate brain death into legislation and medical practice. Several countries, most notably China, still lack laws recognizing brain death and national medical standards for making the diagnosis. The perception is that Asians are less likely to approve of brain death or organ transplant from brain dead donors. Cultural and religious traditions have been referenced to explain this apparent difference. In the West, the status of the brain as home to the soul in Enlightenment philosophy, combined with pragmatism and utilitarianism, supports the concept of brain death. In the East, the integration of body with spirit and nature in Buddhist and folk beliefs, along with the Confucian social structure that builds upon interpersonal relationships, argues against brain death. However, it is unclear whether these reasoning strategies are explicitly used when families and medical providers are faced with acknowledging brain death. Their decisions are more likely to involve a prioritization of values and a rationalization of intuitive responses. Why and whether there might be differences between East and West in the acceptance of the brain death concept requires further empirical testing, which would help inform policy-making and facilitate communication between providers and patients from different cultural and ethnic backgrounds.

A Review of Ancillary Tests in Evaluating Brain Death

The neurological determination of death (NDD) is primarily considered to be clinical. However, situations may arise where confounding factors make this clinical assessment difficult or impossible. As a result, ancillary tests have been developed in order to aid in the confirmation of brain death. As assessment of neuronal electrical activity; electroencephalography (EEG) is no longer recommended in this determination, tools assessing cerebral perfusion, as reflected by the presence or absence of cerebral blood flow (CBF), are the mainstay of NDD. The preferred ancillary test currently is Hexamethylpropylene amine oxime-single photon emission computed tomography (HMPAO SPECT) radionuclide angiography. When this is not available, or is equivocal, 4-vessel cerebral angiography can be used to determine the presence or absence of intracranial blood flow. However, as cerebral angiography has its own limitations, other techniques are sought by physicians in the Intensive Care and Neuro-intensive Care settings to replace cerebral angiography. In this article, we briefly review the history of diagnosis of brain death, pathophysiologic issues in making this determination, and currently available CBF imaging techniques, discussing each in turn with respect to their utility in the diagnosis of brain death.

Bispectral Index Scale variations in patients diagnosed with brain death

INTRODUCTION

Brain death (BD) is defined as the total irreversible loss of brain stem function. According to the Greek legislation, BD diagnosis is based on clinical criteria that test brain stem function. Bispectral Index Scale (BIS), a parameter derived from a mathematical analysis of the electroengephalogram depicts brain activity. The aim of our study was to record BIS alterations in brain-dead patients.

METHODS

Thirty-five brain dead patients according to the clinical criteria were included in this study. All patients were hemodynamically stable, normothermic, and normocapnic, free of oxygenation disturbances and electrolyte abnormalities. Continuous BIS monitoring (BIS XP, A-2000, Aspect Medical Systems, Newton, Mass, USA) was performed in all patients for periods ranging from 24 to 36 hours.

RESULTS

BIS values were 0 for the majority of the study period in all patients. However, in 23 patients the BIS value exceeded 30 for more than 30 minutes. This increase could not be attributed to any external stimulation.

CONCLUSION

BIS is a noninvasive, easily interpreted method to monitor cerebral activity. According to our results, BIS could be helpful in BD confirmation but cannot replace the valid clinical tests, which are consistent with Greek legislation for this diagnosis.

Brain perfusion studies in the evaluation of acute neurologic abnormalities

Two categories of single-photon radiopharmaceuticals for brain perfusion exist, nonlipophilic and lipophilic compounds. The former are useful in performing simple flow examinations which today have application primarily in the determination of brain death. The latter also exhibit a parenchymal uptake phase that allows for evaluation of the distribution of blood flow within the brain. The lipophilic radiopharmaceuticals, therefore, have application in the evaluation of patients following catastrophic brain injury and traumatic brain injury (TBI) and in prognosticating the outcome following cerebral vascular accidents. Use of these agents to monitor therapy with thrombolytic agents, although theoretically helpful, is technically difficult due to the need to institute treatment rapidly, without undue delay.

Clinical Determination of Brain Death

In 2010 an article in the Canadian Journal of Anesthesia1 presented case reports of two patients who appeared to regain spontaneous respiration after they had been determined to be brain dead. The criteria used were those described in the recommendations from the Canadian Council for Donation and Transplantation2. The article was accompanied by an editorial3 that acknowledged the challenges faced by the physicians who determined that brain death had occurred, but concludes that in both cases several of the criteria were either misinterpreted or overlooked. However, it is clearly pertinent to ask if these reports have any implications for the clinical determination of brain death in Australia and New Zealand as described in the Australian and New Zealand Intensive Care Society (ANZICS) Statement on Death and Organ Donation4.

Diagnosis of brain death

Brain death (BD) should be understood as the ultimate clinical expression of a brain catastrophe characterized by a complete and irreversible neurological stoppage, recognized by irreversible coma, absent brainstem reflexes, and apnea. The most common pattern is manifested by an elevation of intracranial pressure to a point beyond the mean arterial pressure, and hence cerebral perfusion pressure falls and, as a result, no net cerebral blood flow is present, in due course leading to permanent cytotoxic injury of the intracranial neuronal tissue. A second mechanism is an intrinsic injury affecting the nervous tissue at a cellular level which, if extensive and unremitting, can also lead to BD. We review here the methodology of diagnosing death, based on finding any of the signs of death. The irreversible loss of cardio-circulatory and respiratory functions can cause death only when ischemia and anoxia are prolonged enough to produce an irreversible destruction of the brain. The sign of such loss of brain functions, that is to say BD diagnosis, is fully reviewed.

Irreversibility: cardiac death versus brain death

The acceptance of brain death (BD) as death of the human being has been progressively accepted beginning in the early 1960s. The issue of irreversibility is directly related to the diagnosis of human death, and it is closely associated with the concept of potentiality, i.e., that some patients still have the potentiality of living. In recent years several authors have proposed to use a cardiocirculatory criterion for death determination in transplant donors. This has aroused ethical and medical controversies regarding concerns to accept that a non-heart-beating donor is really dead. We conclude that the cardiocirculatory criterion of death only assures irreversibility when asystole is prolonged enough to assure that ischemia and anoxia have destroyed the brain. On the contrary, BD fulfills both requirements for death determination: cessation of functions and irreversibility

Towards an effective definition of death and disorders of consciousness

There exists much controversy in providing an effective definition of human death, largely due to the lack of a rigorous separation and ordered formulation of three distinct elements: a universally accepted definition of death, the medical criterion (anatomical substrata) for determining that death has occurred, and the tests to prove that the criterion has been satisfied. The papers herein review medical standards, philosophical arguments, neurophysiological knowledge, behavioural and cognitive theory and the legal ramifications of the brain-oriented standards of death (whole brain, brainstem and higher brain). The papers examine the notion of connectivities and networks of conscious experience in order to formulate an effective definition of death, based on the basic physiopathological mechanisms of consciousness. We cannot simply differentiate and locate arousal as a function of the ascending reticular activating system, and awareness as a function of the cerebral cortex. Substantial interconnections among the brainstem, subcortical structures, and the neocortex are essential integrating components of human consciousness. This paper attempts to reconcile the brain-oriented standards that are currently inconsistent. The thread of the arguments is the basis for a standard of human death that includes consciousness as the most important function of the body, because it provides the capacity for integrating the functions of the body. The notion of consciousness as the ultimate integrative function is more consistent with the biologically-based systems than the more philosophically-based notions of personhood. Both sides of the argument are presented herein.

Is there anybody in there? Detecting awareness in disorders of consciousness

The bedside detection of awareness in disorders of consciousness (DOC) caused by acquired brain injury is not an easy task. For this reason, differential diagnosis using neuroimaging and electrophysiological tools in search for objective markers of consciousness is being employed. However, such tools cannot be considered as diagnostic per se, but as assistants to the clinical evaluation, which, at present, remains the gold standard. Regarding therapeutic management in DOC, no evidence-based recommendations can be made in favor of a specific treatment. The present review summarizes clinical and paraclinical studies that have been conducted with neuroimaging and electrophysiological techniques in search of residual awareness in DOC. We discuss the medical, scientific and ethical implications that derive from these studies and we argue that, in the future, the role of neuroimaging and electrophysiology will be important not only for the diagnosis and prognosis of DOC but also in establishing communication with these challenging patients.

Dying as a social relationship: a sociological review of debates on the determination of death

The research literature about 'brain death' is largely characterized by biomedical, bioethical and legal writing. This has led to overlooking wider but no less pertinent social, historical and cultural understandings about death. By ignoring the work of other social and clinical colleagues in the study of dying, the literature on the determination of death has become unnecessarily abstract and socially disconnected from parallel concerns about death and dying. This has led, and continues to lead to, incomplete suggestions and narrow discussions about the nature of death as well as an ongoing misunderstanding of general public and health care staff responses to brain death criteria. This paper provides a sociological outline of these problems through a review of the key literature on the determination of death.

Self-consciousness in non-communicative patients

The clinical and para-clinical examination of residual self-consciousness in non-communicative severely brain damaged patients (i.e., coma, vegetative state and minimally conscious state) remains exceptionally challenging. Passive presentation of the patient's own name and own face are known to be effective attention-grabbing stimuli when clinically assessing consciousness at the patient's bedside. Event-related potential and functional neuroimaging studies using such self-referential stimuli are currently being used to disentangle the cognitive hierarchy of self-processing. We here review neuropsychological, neuropathological, electrophysiological and neuroimaging studies using the own name and own face paradigm obtained in conscious waking, sleep, pharmacological coma, pathological coma and related disorders of consciousness. Based on these results we discuss what we currently do and do not know about the functional significance of the neural network involved in "automatic" and "conscious" self-referential processing.

Science and society: death, unconsciousness and the brain

The concept of death has evolved as technology has progressed. This has forced medicine and society to redefine its ancient cardiorespiratory centred diagnosis to a neurocentric diagnosis of death. The apparent consensus about the definition of death has not yet appeased all controversy. Ethical, moral and religious concerns continue to surface and include a prevailing malaise about possible expansions of the definition of death to encompass the vegetative state or about the feared bias of formulating criteria so as to facilitate organ transplantation.