On noncongruence between the concept and determination of death

Ethical Issues in Normothermic Regional Perfusion in Controlled Organ Donation After Determination of Death by Circulatory Criteria: A Scoping Review

Normothermic regional perfusion (NRP) is a surgical technique that can improve the quality and number of organs recovered for donation after the determination of death by circulatory criteria. Despite its promise, adoption of NRP has been hindered because of unresolved ethical issues. To inform stakeholders, this scoping review provides an impartial overview of the major ethical controversies surrounding NRP. We undertook this review according to a modified 5-step methodology proposed by Arksey and O'Malley. Publications were retrieved through MEDLINE and Embase. Gray literature was sourced from Canadian organ donation organizations, English-language organ donation organization websites, and through our research networks. Three reviewers independently screened all documents for inclusion, extracted data, and participated in content analysis. Disagreements were resolved through consensus meetings. Seventy-one documents substantively engaging with ethical issues in NRP were included for full-text analysis. We identified 6 major themes encompassing a range of overlapping ethical debates: (1) the compatibility of NRP with the dead donor rule, the injunction that organ recovery cannot cause death, (2) the risk of donor harm posed by NRP, (3) uncertainties regarding consent requirements for NRP, (4) risks to stakeholder trust posed by NRP, (5) the implications of NRP for justice, and (6) NRP's potential to benefits of NRP for stakeholders. We found no agreement on the ethical permissibility of NRP. However, some debates may be resolved through additional empirical study. As decision-makers contemplate the adoption of NRP, it is critical to address the ethical issues facing the technique to ensure stakeholder trust in deceased donation and transplantation systems is preserved.

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.

Controlled Donation After Circulatory Determination of Death: A Scoping Review of Ethical Issues, Key Concepts, and Arguments

Controlled donation after circulatory determination of death (cDCDD) is an important strategy for increasing the pool of eligible organ donors.

Ethical and logistical concerns for establishing NRP-cDCD heart transplantation in the United States

Controlled heart donation after circulatory determination of death (cDCD) is well established internationally with good outcomes and could be adopted in the United States to increase heart supply if ethical and logistical challenges are comprehensively addressed. The most effective and resource-efficient method for mitigating warm ischemia after circulatory arrest is normothermic regional perfusion (NRP) in situ. This strategy requires restarting circulation after declaration of death according to circulatory criteria, which appears to challenge the legal circulatory death definition requiring irreversible cessation. Permanent cessation for life-saving efforts must be achieved to assuage this concern and ligating principal vessels maintains no blood flow to the brain, which ensures natural progression to cessation of brain function. This practice-standard in some countries-raises unique concerns about prioritizing life-saving efforts, informed authorization from decision-makers, and the clinician's role in the patient's death. To preserve public trust, medical integrity, and respect for the donor, the donation conversation must not take place until after an un-coerced decision to withdraw life-sustaining treatment made in accordance with the patient's treatment goals. The decision-maker(s) must understand cDCD procedure well enough to provide genuine authorization and the preservation/procurement teams must be kept separate from the clinical care team.

Permanent brain arrest as the sole criterion of death in systemic circulatory arrest

Historically, there has been a tendency to think that there are two types of death: circulatory and neurological. Holding onto this tendency is making it harder to navigate emerging resuscitative technologies, such as extracorporeal membrane oxygenation and the recent well-publicised experiment that demonstrated the possibility of restoring cellular function to some brain neurons 4 h after normothermic circulatory arrest (decapitation) in pigs. Attempts have been made to respond to these difficulties by proposing a unified brain-based criterion for human death, which we call 'permanent brain arrest'. The clinical characteristics of permanent brain arrest are the permanent loss of capacity for consciousness and permanent loss of all brainstem functions, including the capacity to breathe. These losses could arise from a primary brain injury or as a result of systemic circulatory arrest. We argue that permanent brain arrest is the true and sole criterion for the death of human beings and show that this is already implicit in the circulatory-respiratory criterion itself. We argue that accepting the concept of permanent cessation of brain function in patients with systemic permanent circulatory arrest will help us better navigate the medical advances and new technologies of the future whilst continuing to provide sound medical criteria for the determination of death.

The ethical obligation of the dead donor rule

The dead donor rule (DDR) originally stated that organ donors must not be killed by and for organ donation. Scholars later added the requirement that vital organs should not be procured before death. Some now argue that the DDR is breached in donation after circulatory determination of death (DCDD) programs. DCDD programs do not breach the original version of the DDR because vital organs are procured only after circulation has ceased permanently as a consequence of withdrawal of life-sustaining therapy. We hold that the original rendition of the DDR banning killing by and for organ donation is the fundamental norm that should be maintained in transplantation ethics. We propose separating the DDR from two other fundamental normative rules: the duties to prevent harm and to obtain informed consent.

The Organism as a Whole in an Analysis of Death

Although death statutes permitting physicians to declare brain death are relatively uniform throughout the United States, academic debate persists over the equivalency of human death and brain death. Alan Shewmon showed that the formerly accepted integration rationale was conceptually incomplete by showing that brain-dead patients demonstrated a degree of integration. We provide a more complete rationale for the equivalency of human death and brain death by defending a deeper understanding of the organism as a whole (OaaW) and by using a novel strategy with shared objectives to justify death determination criteria. Our OaaW account describes different types of OaaW, defining human death as the loss of status as a human OaaW. We defend human death as similar to nonhuman death in terms of wakefulness, but also distinct in terms of the sui generis properties, particularly conscious awareness. We thereby defend the equivalency of brain death and human death using a resulting neurocentric rationale.

When are you dead enough to be a donor? Can any feasible protocol for the determination of death on circulatory criteria respect the dead donor rule?

The basic question concerning the compatibility of donation after circulatory death (DCD) protocols with the dead donor rule is whether such protocols can guarantee that the loss of relevant biological functions is truly irreversible. Which functions are the relevant ones? I argue that the answer to this question can be derived neither from a proper understanding of the meaning of the term "death" nor from a proper understanding of the nature of death as a biological phenomenon. The concept of death can be made fully determinate only by stipulation. I propose to focus on the irreversible loss of the capacity for consciousness and the capacity for spontaneous breathing. Having accepted that proposal, the meaning of "irreversibility" need not be twisted in order to claim that DCD protocols can guarantee that the loss of these functions is irreversible. And this guarantee does not mean that reversing that loss is either conceptually impossible or known to be impossible with absolute certainty.

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.

Donation after brain circulation determination of death

Background

The fundamental determinant of death in donation after circulatory determination of death is the cessation of brain circulation and function. We therefore propose the term donation after brain circulation determination of death [DBCDD].

Results

In DBCDD, death is determined when the cessation of circulatory function is permanent but before it is irreversible, consistent with medical standards of death determination outside the context of organ donation. Safeguards to prevent error include that: 1] the possibility of auto-resuscitation has elapsed; 2] no brain circulation may resume after the determination of death; 3] complete circulatory cessation is verified; and 4] the cessation of brain function is permanent and complete. Death should be determined by the confirmation of the cessation of systemic circulation; the use of brain death tests is invalid and unnecessary.

Because this concept differs from current standards, consensus should be sought among stakeholders. The patient or surrogate should provide informed consent for organ donation by understanding the basis of the declaration of death.

Conclusion

In cases of circulatory cessation, such as occurs in DBCDD, death can be defined as the permanent cessation of brain functions, determined by the permanent cessation of brain circulation.

Classic cases revisited: Baby Theresa and the definition of death

As our medical knowledge grows the criteria for the diagnosis of death continue to evolve. The criteria tend to be pragmatic, and are designed to serve the needs of the society. They are however, only a set of tools and as such they fail to address the question of what death actually is. More importantly, a question remains as to what does death mean to us, human beings. The historical case of Baby Theresa challenges the way we think about death, life and organ transplantation.

Changing the conversation about brain death

We seek to change the conversation about brain death by highlighting the distinction between brain death as a biological concept versus brain death as a legal status. The fact that brain death does not cohere with any biologically plausible definition of death has been known for decades. Nevertheless, this fact has not threatened the acceptance of brain death as a legal status that permits individuals to be treated as if they are dead. The similarities between "legally dead" and "legally blind" demonstrate how we may legitimately choose bright-line legal definitions that do not cohere with biological reality. Not only does this distinction bring conceptual coherence to the conversation about brain death, but it has practical implications as well. Once brain death is recognized as a social construction not grounded in biological reality, we create the possibility of changing the social construction in ways that may better serve both organ donors and recipients alike.

Whither brain death?

The publicity surrounding the recent McMath and Muñoz cases has rekindled public interest in brain death: the familiar term for human death determination by showing the irreversible cessation of clinical brain functions. The concept of brain death was developed decades ago to permit withdrawal of therapy in hopeless cases and to permit organ donation. It has become widely established medical practice, and laws permit it in all U.S. jurisdictions. Brain death has a biophilosophical justification as a standard for determining human death but remains poorly understood by the public and by health professionals. The current controversies over brain death are largely restricted to the academy, but some practitioners express ambivalence over whether brain death is equivalent to human death. Brain death remains an accepted and sound concept, but more work is necessary to establish its biophilosophical justification and to educate health professionals and the public.