Describe the legalities of consent for organ donation, including opt-out and deemed consent legislation.
Explain the limits of consent and why there is a need for professional and ethical practice guidance.
Deceased organ donation is built upon two ethical and legal rules: the dead donor and consenting donor rules.
The dead donor rule is standardly formulated as the rule that ‘donors must be determined to be dead before their organs are recovered’.
Worldwide, there are different legislative models for the consenting donor rule: opt-in, opt-out, hybrid and soft or hard enforcement.
Consent to donation may legally permit donation, but it does not mandate that donation occurs or dictate what clinicians should do in a particular circumstance. Clinicians' actions should be guided by professional standards, operating within the boundaries set by law, and based on science, ethics and cultural expectations.
Organ failure and the need for transplantation remain high in all countries. Unmet need can lead to death on the transplant waiting list or commercially driven transplantation. A number of international resolutions and declarations have called on each country to strive toward self-sufficiency in organ donation and transplantation. However, no country has yet achieved this goal. We therefore face common barriers to increasing rates of donation across all social groups, ethnicities and religions. Any response cannot be at the expense of the two ethical and legal rules upon which deceased organ donation is based.
The first rule is the dead donor rule (DDR). This rule was coined as a phrase by John Robertson in 1988, but the principle it is based upon is much older. 1 The Journal of the American Medical Association published a landmark paper in 1968 from the Ad Hoc Committee of the Harvard Medical School, which established ‘irreversible coma’ as an acceptable criterion for diagnosing death. Less well known is that in the same edition of the journal, the Judicial Council of the American Medical Association published ethical guidelines for organ transplantation. 2 Two ethical rules emerged from the guidance that have been fundamental to transplantation policy ever since. Firstly, the rule that would become the DDR: ‘When a vital, single organ is to be transplanted, the death of the donor shall have been determined by at least one physician other than the recipient's physician’. Secondly, the rule that ‘full discussion of the proposed procedure with the donor and the recipient or their responsible relatives or representatives is mandatory’. This second rule, although not officially phrased as such, can be understood as the consenting donor rule—someone must have consented to the organ removal.
This paper explores the two rules further, providing an international context on current challenges and how different jurisdictions have sought to uphold the organ donation rules that are as old as transplantation itself. Supplementary material summarising current and historical guidance, legal cases and UK donation statistics referred to within this article is available.
The standard formulation of the DDR is that ‘donors must be determined to be dead before their organs are removed’, but a number of alternative formulations have emerged over time. 3 One is narrow in scope, where the DDR is understood to be merely a prohibition on killing the patient for organ donation. On this understanding of the rule, if a dying patient had both kidneys removed, followed by the withdrawal of life-sustaining treatment (WLST), one could still theoretically satisfy the DDR, as death would follow treatment withdrawal (over hours) and not death by renal failure (over days). 4 Needless to say, such an interpretation and application have not been implemented. An alternative and broader formulation of the DDR would prohibit any actions for organ donation (e.g. consulting the organ donor register and maintaining stable physiology) whilst the patient is still alive. 5 Table 1 illustrates how the two types of deceased organ donation may satisfy these differing formulations of the DDR. What is immediately apparent is that donation rests upon accurate and accepted criteria for diagnosing death.
Types of deceased organ donation and their satisfaction of differing formulations of the dead donor rule.
| Formulations of the dead donor rule | Satisfaction of the dead donor rule | |
|---|---|---|
| Donation after the diagnosis of death using neurological criteria | Donation after the diagnosis of death using circulatory criteria | |
| Narrow: ‘the killing of patients for organ donation is prohibited’ | Yes | Yes, provided procedures before death (e.g. heparin) do not hasten death |
| Standard: ‘donors must be determined to be dead before their organs are removed’ | Yes, provided neurological criteria for death are accepted | Yes, provided standard circulatory criteria for death are accepted |
| Broad: ‘procedures for organ donation should not be initiated whilst the patient is still alive’ | Yes, procedures for donation can be delayed until after death | Uncontrolled: Yes, provided standard circulatory criteria for death are accepted Controlled: No, as procedures for organ donation (e.g. blood tests for organ matching) must occur before treatment withdrawal and death |
For donation after the diagnosis of death using neurological criteria (donation after neurological death or donation after brain death), provided neurological criteria for death are legally accepted in the relevant jurisdiction and the criteria are appropriately met, the DDR is fully satisfied. Neurological criteria for death have been legally accepted in many nations since the 1960s and 1970s, and the clinical criteria have not significantly changed over that time. However, there has also been an international conceptual shift in the definition of death toward the UK position (emphasising brainstem, breathing and consciousness) (see Table 2 ), and including, as in this paper, a move away from the confusing term ‘brain death’.
Evolving definitions of death over time (see further reading, Supplementary material). UDDA, Uniform Determination of Death Act.
| Document | Definition of death |
|---|---|
| Ad Hoc Committee of the Harvard Medical School, 1968, USA | ‘Our primary purpose is to define irreversible coma as a new criterion for death… A permanently non-functioning brain represent[s] the death of the individual’. |
| Conference of Medical Royal Colleges and their faculties, 1976, UK | ‘Permanent functional death of the brain stem constitutes brain death’. |
| Conference of Medical Royal Colleges and their faculties, 1979, UK | ‘Whatever the mode of its production, brain death represents the stage at which a patient becomes truly dead’. |
| UDDA, 1981, USA | ‘An individual who has sustained either (1) irreversible cessation of circulatory and respiratory functions, or (2) irreversible cessation of all functions of the entire brain, the brain stem, is dead. A determination of death must be made in accordance with accepted medical standards’. |
| Academy of Medical Royal Colleges, 1998, UK | ‘Death entails the irreversible loss of those essential characteristics which are necessary to the existence of a living human person. Thus, it is recommended that the definition of death should be regarded as “irreversible loss of the capacity for consciousness, combined with irreversible loss of the capacity to breathe.” The irreversible cessation of brain stem function (brain stem death) whether induced by intracranial events or the result of extra-cranial phenomena, such as hypoxia, will produce this clinical state and therefore brain stem death equates with the death of the individual’. |
| Academy of Medical Royal Colleges, 2008, UK | ‘Death entails the irreversible loss of those essential characteristics which are necessary to the existence of a living human person and, thus, the definition of death should be regarded as the irreversible loss of the capacity for consciousness, combined with irreversible loss of the capacity to breathe… The irreversible cessation of brain-stem function whether induced by intracranial events or the result of extra-cranial phenomena, such as hypoxia, will produce this clinical state and therefore irreversible cessation of the integrative function of the brain-stem equates with the death of the individual and allows the medical practitioner to diagnose death’. |
| International Guidelines for Determination of Death Phase 1 participants, in collaboration with the WHO, 2014 | ‘Operational definition of human death: Death is the permanent loss of capacity for consciousness and all brainstem functions. This may result from permanent cessation of circulation or catastrophic brain injury. In the context of death determination, “permanent” refers to loss of function that cannot resume spontaneously and will not be restored through intervention’. |
| American Academy of Neurology (AAN), 2019, USA | ‘The AAN endorses the UDDA definition that brain death has occurred when the irreversible loss of all functions of the entire brain, including the brainstem, has been determined by the demonstration of complete loss of consciousness (coma), brainstem reflexes, and the independent capacity for ventilatory drive (apnea). It recognizes that neuroendocrine function may persist in patients with irreversible injury to the brain and brainstem’. |
| World Brain Death Project, 2020 | ‘[Brain death/death by neurologic criteria (BD/DNC)] is defined as the complete and permanent loss of brain function as defined by an unresponsive coma with loss of capacity for consciousness, brainstem reflexes, and the ability to breathe independently. This may result from permanent cessation of oxygenated circulation to the brain and/or after devastating brain injury. Persistence of cellular-level neuronal and neuroendocrine activity does not preclude the determination. In the context of death determination, “permanent” refers to loss of function that cannot resume spontaneously and will not be restored through intervention’. |
One late 20th century definition of death was that death is the irreversible cessation of the integrated functioning of the organism as a whole. The idea that neurological death satisfied this definition was based on the false assumption that the brain is the integrator of the organism's vital functions (e.g. heart). 6 A better rationale is emerging, which is that the brain is what makes us the people that we are. If a person's brain were removed from the skull and destroyed, the person would be dead even if the rest of the head and body were sustained artificially. This has been the UK position since the 1970s, which has held that whatever the mode of its production, ‘brain death’ represents the stage at which a patient becomes truly dead. One criticism of this concept is that neurological death reflects a Western Cartesian view (mind and body are separate) rather than the holistic views typical of other Eastern cultures and religions. 7
Another criticism is that in some statutes, diagnosing death using neurological criteria (DNC) requires the irreversible cessation of all functions of the entire brain (USA) or all functions of the brain (Australia). Recognising that some neurological functions (such as hypothalamic function) may persist after DNC, the American Academy of Neurology has defended the status quo by arguing that the preservation of some of these functions does not invalidate the determination of brain death. However, a declaration of death when there is persisting brain function does not comply with the wording of USA statutes and so remains open to legal challenge. As endocrine functions of the brain do not relate in any way to the presence of consciousness and arousal, it is desirable to see the statutes amended to bring them more into line with the irreversible loss of brainstem function criterion used in other countries, such as the UK. 8 There is growing worldwide support for updating the definition of death. 9
Even with an accepted worldwide rationale, and updated statutes, not all families will be willing to accept either the concept or the finality of a diagnosis of DNC. In a world where experts are less trusted, it is perhaps no surprise that legal challenges to neurological criteria for death are therefore increasing in frequency. To date, none have been successful in reversing a DNC diagnosis. 8
One might have thought, therefore, that donation after the diagnosis of death using circulatory (cardiorespiratory) criteria (DCD) would be less controversial and satisfy the DDR more easily. However, that is not the case. Table 1 highlights the concern that medications that may be given before death, such as heparin and phentolamine, might hasten death. 10 , 11 It is theoretically possible that heparin will cause further bleeding, especially given that patients eligible for DCD with brain haemorrhage and trauma form the largest pool of potential donors; the use of phentolamine may cause hypotension. 12 The 2009 England and Wales, ‘legal issues relevant to non-heart beating organ donation’ identified heparin as an intervention that places the person at risk of serious harm, and therefore is ‘unlikely ever to be in the person's best interests'. The same position is taken in New South Wales in Australia (see Supplementary material). The rest of the world takes a different view, and pre-death heparin administration represents routine practice for DCD in many countries.
There is some debate concerning whether the circulatory criteria used in donation (particularly the 5 min observation period to ensure the possibility of autoresuscitation has passed) are acceptable for diagnosing death. 11 , 13 , 14 This debate is more problematic in countries that have no nationally established criteria for diagnosing death outside of donation contexts, such as in the USA, Canada and Australia. The UK's position is stronger, as it uses the same criteria for diagnosing death irrespective of organ donation. The 5 min standard was actually proposed in 1846 by Eugène Bouchut, well before organ donation was considered possible. 15 Bouchut advocated the use of the stethoscope as a technological aid to diagnose death. When the heartbeat was absent for 5 min, a person could be diagnosed dead. He also considered that it should be doctors who diagnose death (previously it had been family members and priests). The Academy of Sciences in Paris, France accepted Bouchut's view that this would aid public safety in preventing premature burial and assist with death certification and coronial investigations.
The debate about the criterion of a 5 min observation period often centres around the terms ‘irreversible’ and ‘permanent’.16, 17, 18, 19 ‘Irreversible’ is the term most commonly seen in statutes or codes of practice, but this is perhaps a historical anomaly, as the earliest documents often used the two terms interchangeably. More modern usage defines irreversible as ‘pertaining to a situation or condition that will not or cannot return or resume’ (i.e. even with advanced resuscitation techniques, the circulation cannot be restored by anyone under any circumstances at a time now or in the future) and permanent as ‘pertaining to a situation or condition that will not return to its previous state’ (i.e. the circulation will not resume spontaneously and will not be restored through intervention) ( Table 2 ). A concept of permanence for diagnosing death is in keeping with usual hospital practice. A diagnosis of death is not dependent upon a failed resuscitation attempt or waiting a prolonged time after circulatory arrest until the patient becomes theoretically impossible to resuscitate (possibly several hours if extracorporeal membrane oxygenation [ECMO] were being used). 20 It is more usual for doctors to diagnose death using the criterion of permanence rather than irreversibility, and therefore, if professionally and legally accepted, donors after the diagnosis of death using circulatory criteria do satisfy the standard formulation of the DDR.
An associated challenge is the question of whether, if circulation to only part of the body was restored, this would invalidate the diagnosis of death using circulatory criteria. UK definitions and criteria for death are very clear that it is cessation of cerebral perfusion that counts, not perfusion to other parts of the body. This has allowed the UK to develop normothermic regional perfusion (NRP) techniques, where an ECMO-like circuit is used after death to perfuse abdominal organs and restore their function whilst simultaneously isolating the restored circulation from the thoracic organs. 21 Some countries, notably Spain and France, have also developed NRP programmes, but others, like Australia and the USA, have been limited by the statutory requirements in their definitions of death prohibiting the restoration of circulation in the body. A number of European centres, such as the Royal Papworth Hospital NHS Foundation Trust in the UK, have piloted NRP for thoracic organs with accompanying isolation of the cerebral circulation, which leads to the heart restarting in the body after death, but without cerebral perfusion. 22 The advantage of this technique for DCD heart donation, over the more common technique (in the UK and Australia) of direct and rapid retrieval of the heart and placing the heart on a machine perfusion device outside of the body, is a hoped-for reduction in warm ischaemic damage and better functional assessment before organ retrieval. 22 Both abdominal and thoracic NRP rely upon interventions that prevent cerebral circulation being restored after death. A Canadian and UK proposal was recently published, which included a detailed anatomical examination to prevent any unexpected collateral blood flow to the brain. 23
Perhaps a greater challenge for DCD is when a broad formulation of the DDR is considered ( Table 1 ). Here, the consideration is not whether the patient is dead when organ recovery commences, but whether the patient is dead before actions or procedures necessary for organ donation commence. In uncontrolled DCD (death diagnosed after failed cardiopulmonary resuscitation in the emergency department), donation procedures can be delayed until after death. But, for the main type of DCD in the world, controlled DCD, which follows a decision to WLST, certain donation procedures (e.g. blood tests for organ matching, delaying withdrawal until the organ retrieval team is present and ready, potentially moving the patient from the ICU for WLST) must occur before death. However, whilst a broad DDR formulation can never be satisfied in controlled DCD, ethics, law and professional practice have implicitly advanced the view that it is the consenting donor rule that is the pre-eminent consideration in living patients in the hours before their death and subsequent donation after the diagnosis of death using circulatory criteria (see Supplementary material).
Two rules must be met for organs to be removed from a deceased patient: he or she must be dead (see the aforementioned analysis), and someone must have consented to the removal of organs. The two-key decision makers regarding consent to donation are the patient and the patient's family, which can comprise many different decision makers. Sometimes, there is a disagreement between family members about whether donation should take place, and sometimes the collective family decision can contradict that of the patient. In such situations, the question of which decision is decisive depends on the model of consent used in a given jurisdiction. Worldwide, the different systems for organ donation consent are opt-in, opt-out, hybrid and either soft or hard enforcement ( Table 3 ). Since the introduction of opt-out in Wales in 2015, England in 2020 and Scotland from 2021, in addition to maintaining the ability to opt-in, the UK is best described as having a soft hybrid system.
Examples of systems for organ donation consent.