In the world of medical ethics, few topics have stirred as much debate as the use of normothermic regional perfusion (NRP) in controlled donation after circulatory determination of death (cDCDD). At the center of this debate is a compelling question: does NRP invalidate the circulatory criteria for death, effectively resuscitating the donor? Dr. Emil J. N. Busch from the University of Oslo tackles this very question in a recent paper, striving to dispel doubts and misconceptions surrounding this controversial procedure.
The American College of Physicians (ACP) voiced four main concerns about NRP-cDCDD: interference with the natural course of death, potential violation of the circulatory death criteria, injustice towards stigmatized populations, and lack of transparency in clinical practices. Dr. Busch's paper aims to address and refute the idea that NRP resuscitates the deceased, thereby challenging the second of ACP's concerns.
To appreciate the scope of Dr. Busch's work, it's essential first to understand what NRP and cDCDD entail. Unlike the traditional method of organ donation after brain death (DBD), cDCDD involves removing organs after the irreversible cessation of circulatory and respiratory functions. NRP takes this a step further by restoring circulation to certain organs post-mortem to improve their viability for transplantation. This technique, according to some critics, undermines the definition of circulatory death by resuming blood flow, akin to 'bringing the dead back to life.'
Dr. Busch sets out to debunk this notion by examining the philosophical and practical standards used to determine death. According to the 1981 report by the President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research, death is defined as the "death of the organism as a whole." This definition underscores that an organism is considered dead not because its circulatory or respiratory functions have ceased per se, but because these losses signify that the organism can no longer operate as an integrated whole.
In essence, NRP does not restore the organism's ability to function in an integrated manner. Although it re-establishes regional blood flow, NRP deliberately excludes circulation to the brain, preventing any chance of restoring cognitive or neurological functions. This distinction is crucial because it implies that while certain organs may regain perfusion, the organism as a whole remains non-functional and, therefore, deceased.
Furthermore, Dr. Busch points out that in typical cDCDD protocols, a 'no-touch' period of five minutes follows the cessation of circulatory functions. This period ensures that autoresuscitation – the spontaneous restarting of the heart – does not occur. Once this period has passed and the individual is declared dead under circulatory criteria, the application of NRP does not contravene this declaration because it does not reestablish the organism's capacity for integrated function, especially in the absence of brain perfusion.
Historical context also provides insight into the debate. The concept of death has always been fraught with complexity, often hinging on a combination of medical, ethical, and philosophical considerations. The brain death criteria, for example, were established to address organ donation's ethical demands and the need for practical and reliable indicators of death. Similarly, the circulatory death criteria aim to unequivocally demonstrate that the organism's vital integrative functions have ceased. Dr. Busch's arguments align with these established standards, promoting a nuanced understanding of death beyond mere mechanical functions.
One crucial aspect of Dr. Busch's argument is distinguishing between permanent cessation and irreversibility in the context of circulatory and respiratory functions. According to the ACP, death is defined by the permanent cessation of these functions, meaning they cannot resume spontaneously or be restored medically. NRP, however, does not disrupt this permanence because the reestablished circulation is regional and does not restore the circulatory and respiratory functions required for the organism to function wholly.
Dr. Busch's examination extends to the ethical considerations surrounding NRP-cDCDD. The dead donor rule (DDR), a fundamental ethical principle in organ donation, mandates that organ procurement must neither cause nor hasten the donor's death. By adhering strictly to this rule, NRP-cDCDD protocols ensure that death's declaration precedes any intervention to restore regional circulation. Therefore, the application of NRP does not violate DDR as it maintains the integrity of the death determination process.
In practical terms, the use of NRP in cDCDD has been shown to offer significant benefits, including reducing post-transplant complications and allowing for the functional assessment of hearts before transplantation. Studies have indicated that organs retrieved through NRP protocols may exhibit better viability and function, thereby enhancing transplant outcomes. This practical advantage further supports the ethical justification for employing NRP within the stringent framework of cDCDD protocols.
Dr. Busch also addresses the methodological challenges and concerns raised by NRP's critics. For instance, there is a concern that even with clamping or blocking techniques, some residual blood flow might reach the brain, potentially reigniting some level of brain function. However, evidence from animal studies, such as those involving porcine models, suggests that clamping the aortic arch effectively prevents brain reperfusion, thereby supporting the claim that the circulatory criteria for death are not violated under NRP.
It's worth noting that translating outcomes from animal models to clinical settings requires caution. Nevertheless, these preliminary findings offer a degree of confidence in the efficacy of NRP when appropriately managed. By ensuring that circulation is regionally confined and specifically excluding the brain, NRP can maintain the integrity of the death determination criteria while optimizing organ preservation for transplantation.
The implications of Dr. Busch's findings are profound. They not only provide a robust rebuttal to the ACP's concerns about NRP invalidating circulatory death but also reinforce the ethical and practical viability of this technique within organ donation protocols. By framing death as a state where the organism can no longer function as an integrated whole, Dr. Busch clarifies that NRP, when applied with stringent controls, does not resuscitate the donor but rather supports the ethical imperative of enhancing transplant outcomes.
Future research and ongoing ethical discourse will undoubtedly continue to shape our understanding and application of NRP in organ donation. As Dr. Busch concludes, "The ruling out of autoresuscitation within the no-touch period and the controlled application of NRP ensures that the fundamental criteria for the determination of death are upheld, thereby addressing both practical and ethical considerations" .
