诊断脑死亡的伦理思考

随着医学的进步和社会的发展,死亡的定义、诊断标准和医生道德责任有了新的内容,脑死亡就是生命终结已为医学界普遍接受.诊断脑死亡是非常专业的技术性工作,有权进行脑死亡诊断的医疗单位和医生必须达到相应的资质要求.确诊和宣布脑死亡应遵循的伦理准则包含多方面的内容,如家属应有死亡标准选择权、脑死亡的诊断程序、脑死亡诊断结果的宣布和生效等方面的问题.     

脑死亡判定的伦理学及实践中的几个问题

脑死亡是临床实践中的常见问题,随着当代医学科学的发展,经过临床严格的判定程序,患者脑死亡即生物学死亡已经成为科学标准,但由于我国在脑死亡立法、公众认知以及医生的各种心理考量,在我国开展脑死亡的判定还存在许多障碍。我们结合自己在判定患者脑死亡后的医患心理变化,以及存在的一些问题,期望引起更多的医学、法学和社会学家关注,使得临床医生对脑死亡的判定,顺应科学发展又能符合患者及其家属的最大利益。     

死亡的判定

死亡是生命的终结.死亡判定的标准在历史上经历了一个逐步深化的过程.1959年2位法国医学家首先提出了脑死亡的概念.但是什么是脑死亡,以及如何判定脑死亡是一个有争议的问题.1981年美国总统委员会提出了一个脑死亡的判定指标体系,并被一些国家立法接受.回顾了对死亡判定认识的历史过程.     

对我国脑死亡立法问题的反思

在对1999年以来我国脑死亡问题的研究成果进行初步梳理的基础上,针对我国学者主张脑死亡立法的主要论据,提出并分析了脑死亡问题的三个主要问题：（1）脑死亡是真正的死亡吗？（2）能否以经济效率的考量来定义生死？（3）器官移植和脑死亡到底有什么关系？还提出,脑死亡立法需要在我国现实的医疗卫生条件下进行讨论。     

Personal identity and brain death: a critical response

The authors contend that there are logical inconsistencies in a theory put forth by Michael Green and Daniel Wikler ("Brain death and personal identity," Philosophy and Public Affairs 1980 Winter; 9(2): 105-133) to justify the brain death concept of death. Green and Wikler had asserted that individuals cease to exist and are dead when the criteria for continuity in their personal identity are not met. Having argued that the theory of personal identity is misguided, Agich and Jones suggest that further research into the ontological foundation of brain death concepts should begin, not by rejecting medical or moral considerations, but by carefully defining the main competing concepts of brain death as brain stem death, cerebral death, death of the brain as a whole, and whole brain death, and then by relating these concepts to the ontological conditions for being a live individual or person.     

The EEG as confirmatory evidence of brain death: Previous and current approaches

The role of EEG in confirming the clinical diagnosis of isolated brain death has undergone evolutionary changes since the original recommendations concerning its use. Accumulated evidence now supports that approach that the EEG can be used not only as a confirmatory test for brain death, but one which considerably facilitates making the diagnosis. Using the EEG, brain death can often be identified with absolute certainty within just a few, rather than the previously recommended 24 or more hours after a known precipitating event. Guidelines to this effect have now been established.     

Mental models and omissive causation

Some causal relations refer to causation by commission (e.g., “A gunshot causes death”), and others refer to causation by omission (e.g., “Not breathing causes death”). We describe a theory of the representation of omissive causation based on the assumption that people mentally simulate sets of possibilities—mental models—that represent causes, enabling conditions, and preventions (Goldvarg & Johnson-Laird, 2001). The theory holds that omissive causes, enabling conditions, and preventions each refer to distinct sets of possibilities. For any such causal relation, reasoners typically simulate one initial possibility, but they are able to consider alternative possibilities through deliberation. These alternative possibilities allow them to deliberate over finer-grained distinctions when reasoning about causes and effects. Hence, reasoners should be able to distinguish between omissive causes and omissive enabling conditions. Four experiments corroborated the predictions of the theory. We describe them and contrast the results with the predictions of alternative accounts of causal representation and inference.     

The ethics of donation and transplantation: are definitions of death being distorted for organ transplantation?

A recent commentary defends 1) the concept of 'brain arrest' to explain what brain death is, and 2) the concept that death occurs at 2–5 minutes after absent circulation. I suggest that both these claims are flawed. Brain arrest is said to threaten life, and lead to death by causing a secondary respiratory then cardiac arrest. It is further claimed that ventilation only interrupts this way that brain arrest leads to death. These statements imply that brain arrest is not death itself. Brain death is a devastating state that leads to death when intensive care, which replaces some of the brain's vital functions such as breathing, is withdrawn and circulation stops resulting in irreversible loss of integration of the organism. Circulatory death is said to occur at 2–5 minutes after absent circulation because, in the context of DCD, the intent is to not attempt reversal of the absent circulation. No defense of this weak construal of irreversible loss of circulation is given. This means that paents in identical physiologic states are dead (in the DCD context) or alive (in the resuscitation context); the current state of death (at 2–5 minutes) is contingent on a future event (whether there will be resuscitation) suggesting backward causation; and the commonly used meaning of irreversible as 'not capable of being reversed' is abandoned. The literature supporting the claim that autoresuscitation does not occur in the context of no cardiopulmonary resuscitation is shown to be very limited. Several cases of autoresuscitation are summarized, suggesting that the claim that these cases are not applicable to the current debate may be premature. I suggest that brain dead and DCD donors are not dead; whether organs can be harvested before death from these patients whose prognosis is death should be debated urgently.     

Neuroscience and Brain Death Controversies: The Elephant in the Room

The conception and the determination of brain death continue to raise scientific, legal, philosophical, and religious controversies. While both the President’s Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research in 1981 and the President’s Council on Bioethics in 2008 committed to a biological definition of death as the basis for the whole-brain death criteria, contemporary neuroscientific findings augment the concerns about the validity of this biological definition. Neuroscientific evidentiary findings, however, have not yet permeated discussions about brain death. These findings have critical relevance (scientifically, medically, legally, morally, and religiously) because they indicate that some core assumptions about brain death are demonstrably incorrect, while others lack sufficient evidential support. If behavioral unresponsiveness does not equate to unconsciousness, then the philosophical underpinning of the definition based on loss of capacity for consciousness as well as the criteria, and tests in brain death determination are incongruent with empirical evidence. Thus, the primary claim that brain death equates to biological death has then been de facto falsified. This conclusion has profound philosophical, religious, and legal implications that should compel respective authorities to (1) reassess the philosophical rationale for the definition of death, (2) initiate a critical reappraisal of the presumed alignment of brain death with the theological definition of death in Abrahamic faith traditions, and (3) enact new legislation ratifying religious exemption to death determination by neurologic criteria.     

脑死亡立法的艰难与中国传统文化

因中国传统伦理文化对人们意识观念的深刻影响导致中国脑死亡立法步履艰难。从中国传统文化视角分析中国的脑死亡及相关伦理问题,提出中国脑死亡诊断标准的制定必须充分考虑民族心理感受,要立足于民族文化理性地探索“中国脑死亡”。     

脑死亡立法的若干法律问题探讨

因为关系到基本人权,脑死亡立法应当由全国人民代表大会立法通过。制定科学的脑死亡标准和严谨的脑死亡判定程序是保障其接近正义的必需。在脑死亡判定方面应充分地保障患者生命权、自主选择权,尊重患者以及家属的知情同意权,保障患者的基本权利是脑死亡立法的核心所在。器官移植不是脑死亡立法的理由。     

Epistemology of brain death determination

This article assesses what standards of safety and certainty of diagnosis need to be met in the determination of brain death. Recent medical, legal, and philosophical developments on brain death are summarized. It is argued that epistemologically adequate standards require the finding of whole-brain death rather than destruction of the cortex. Because of the possibility of positive error in misdiagnosing death, a tutioristic approach of ‘being on the safe side’ is advocated. Given uncertainties in diagnosis of so-called vegetative states like the apallic syndrome, anything less than whole-brain death, especially given the present state of diagnostic capability, should not qualify as an argument for removing therapy specifically on grounds that the patient is dead.     

Temporal Finitude and Finitude of Possibility: The Double Meaning of Death in Being and Time

Abstract

The confusion surrounding Heidegger’s account of death in Being and Time has led to severe criticisms, some of which dismiss his analysis as incoherent and obtuse. I argue that Heidegger’s critics err by equating Heidegger’s concept of death with our ordinary concept. As I show, Heidegger’s concept of death is not the same as the ordinary meaning of the term, namely, the event that ends life. But nor does this concept merely denote the finitude of Dasein’s possibilities or the groundlessness of existence, as William Blattner and Hubert Dreyfus have suggested. Rather, I argue, the concept of death has to be understood both as temporal finitude and as finitude of possibility. I show how this reading addresses the criticisms directed at Heidegger’s death analysis as well as solving textual problems generated by more limited interpretations of the concept.     

Informed consent for the diagnosis of brain death: a conceptual argument

Background

This essay provides an ethical and conceptual argument for the use of informed consent prior to the diagnosis of brain death. It is meant to enable the family to make critical end-of-life decisions, particularly withdrawal of life support system and organ donation, before brain death is diagnosed, as opposed to the current practice of making such decisions after the diagnosis of death. The recent tragic case of a 13-year-old brain-dead patient in California who was maintained on a ventilator for over 2 years illustrates how such a consent would have made a crucial difference.

Methods

Conceptual, philosophical, and ethical analysis.

Results

I first consider a conceptual justification for the use of consent for certain non-beneficial and unwanted medical diagnoses. I suggest that the diagnosis of brain death falls into this category for some patients. Because the diagnostic process of brain death lacks the transparency of traditional death determination, has a unique epistemic structure and a complex risk-benefit profile which differs markedly from case to case, and presents conflicts of interest for physicians and society, I argue that pre-diagnostic counseling and informed consent should be part of the diagnostic process. This approach can be termed as “allow cardiac death”, whose parallel logic with “allow natural death” is discussed. I also discuss potential negative impacts on organ donation and health care cost from this proposal and offer possible mitigation. I show that the pre-diagnostic counseling can improve the possibility for well-thought-out decisions regarding organ donation and terminating life-support system in cases of hopeless prognosis. This approach differs conceptually from the pluralism of the definition of death, such as those in New Jersey and Japan, and it upholds the Uniform Determination of Death Act.

Conclusions

My intention is not to provide an instant panacea for the ongoing impasse of the brain death debate, but to point to a novel conceptual ground for a more pragmatic, and more patient- and family-centered approach. By enabling the family to consent to or decline the diagnostic process of brain death, but not to choose the definition of death, it upholds the current legal definition of death.

     

Death and organ procurement: public beliefs and attitudes

Although "brain death" and the dead donor rule--i.e., patients must not be killed by organ retrieval--have been clinically and legally accepted in the U.S. as prerequisites to organ removal, there is little data about public attitudes and beliefs concerning these matters. To examine the public attitudes and beliefs about the determination of death and its relationship to organ transplantation, 1351 Ohio residents >18 years were randomly selected and surveyed using random digit dialing (RDD) sample frames. The RDD telephone survey was conducted using computer-assisted telephone interviews. The survey instrument was developed from information provided by 12 focus groups and a pilot study of the questionnaire. Three scenarios based on hypothetical patients were presented: "brain dead," in a coma, or in a persistent vegetative state (PVS). Respondents provided personal assessments of whether the patient in each scenario was dead and their willingness to donate that patient's organs in these circumstances. More than 98 percent of respondents had heard of the term "brain death," but only one-third (33.7%) believed that someone who was "brain dead" was legally dead. The majority of respondents (86.2%) identified the "brain dead" patient in the first scenario as dead, 57.2 percent identified the patient in a coma as dead (Scenario 2), and 34.1 percent identified the patient in a PVS as dead (Scenario 3). Nearly one-third (33.5%) were willing to donate the organs of patients they classified as alive for at least one scenario, in seeming violation of the dead donor rule. Most respondents were not willing to violate the dead donor rule, although a substantial minority was. However, the majority of respondents were unaware, misinformed, or held beliefs there were not congruent with current definitions of "brain death." This study highlights the need for more public dialogue and education about "brain death" and organ donation.     

The dead donor rule: how much does the public care...and how much should we care?

In this brief commentary, we reflect on the recent study by Siminoff, Burant, and Youngner of public attitudes toward "brain death" and organ donation, focusing on the implications of their findings for the rules governing from whom organs can be obtained. Although the data suggest that many seem to view "brain death" as "as good as death" rather than "dead" (calling the dead donor rule into question), we find that the study most clearly demonstrates that understanding an individual's definition of death is neither a straightforward task nor a good predictor of views about donation. Reflecting on the implications for ongoing debates over the dead donor rule, we suggest that perhaps it is not a change in policy that is warranted, but rather a change in the priorities that have garnered such intense focus on this issue within the field of bioethics.     

The Ohio study in light of national data and clinical experience

The Siminoff, Burant, and Youngner study in Ohio is strikingly consistent with data from a national study. Both suggest that there might be significant public acceptance of future policies that violate the dead donor rule, or that further extend the boundary between life and death to include brain-damaged patients short of "brain death." Experience with donation suggests that many individuals would donate their loved ones' organs when they have concluded that the brain injury is not survivable, even if all the criteria for "brain death" are not met. It would be very helpful to have research on those who have gone through the real-life clinical situation. Based on the findings of this study and the increasing demand for organs, it may be appropriate for public policy to allow for ways to increase organ procurement from individuals who are not fully "brain dead" beyond the current method of procurement after cardiac death, but any change in this area should go slowly and with significant public input.     

Carson Strong's “positive killing and the irreversibly unconscious patient”: A commentary

There is general agreement that death of the entire brain results in death of the person, and that such a condition can exist in a body which is still technically “alive.”1,2 Dr. Strong additionally contends that in cases of irreversible coma, since cognitive abilities characteristic of the person are no longer manifest and cannot be expected to reappear, such an individual no longer has the “right to life” and somatic death can be initiated by “positive killing.” This, the author claims, can be considered a logical and morally acceptable extension of the conceptual framework now in force for dealing with cases of isolated brain death.     

The degree of certainty in brain death: probability in clinical and Islamic legal discourse

The University of Michigan conference “Where Religion, Policy, and Bioethics Meet: An Interdisciplinary Conference on Islamic Bioethics and End-of-Life Care” in April 2011 addressed the issue of brain death as the prototype for a discourse that would reflect the emergence of Islamic bioethics as a formal field of study. In considering the issue of brain death, various Muslim legal experts have raised concerns over the lack of certainty in the scientific criteria as applied to the definition and diagnosis of brain death by the medical community. In contrast, the medical community at large has not required absolute certainty in its process, but has sought to eliminate doubt through cumulative diagnostic modalities and supportive scientific evidence. This has recently become a principal model, with increased interest in data analysis and evidence-based medicine with the intent to analyze and ultimately improve outcomes. Islamic law has also long employed a systematic methodology with the goal of eliminating doubt from rulings regarding the question of certainty. While ample criticism of the scientific criteria of brain death (Harvard criteria) by traditional legal sources now exists, an analysis of the legal process in assessing brain death, geared toward informing the clinician’s perspective on the issue, is lacking. In this article, we explore the role of certainty in the diagnostic modalities used to establish diagnoses of brain death in current medical practice. We further examine the Islamic jurisprudential approach vis-à-vis the concept of certainty (yaqīn). Finally, we contrast the two at times divergent philosophies and consider what each perspective may contribute to the global discourse on brain death, understanding that the interdependence that exists between the theological, juridical, ethical, and medical/scientific fields necessitates an open discussion and active collaboration between all parties. We hope that this article serves to continue the discourse that was successfully begun by this initial interdisciplinary endeavor at the University of Michigan.     

Secular Epiphanies: The Anatheistic Hermeneutics of Gerard Manley Hopkins

What might epiphany mean for a “secular” society? What does it mean after the death of God? This article explores the hermeneutics of immanent, planetary epiphanies in the work of Gerard Manley Hopkins. In the creative spaces between author, text, and reader new possibilities for becoming enter the world. As such we might be able to name these anatheistic epiphanies.