Rady, Mohamed Y.

Left ventricular assist devices (LVADs) and total artificial hearts (TAHs) are surgically implanted as permanent treatment of unrecoverable heart failure. Both LVADs and TAHs are durable mechanical circulatory support (MCS) devices that can prolong patient survival but also alter end-of-life trajectory. The permissibility of discontinuing assisted circulation is controversial because device deactivation is a life-ending intervention. Durable MCS is intended to successfully replace native physiological functions in heart disease. We posit that the presence of new lethal pathophysiology (ie, a self-perpetuating cascade of abnormal physiological processes causing death) is a central element in evaluating the permissibility of deactivating an LVAD or a TAH. Consensual discontinuation of durable MCS is equivalent with allowing natural death when there is an onset of new lethal pathophysiology that is unrelated to the physiological functions replaced by an LVAD or a TAH. Examples of such lethal conditions include irreversible coma, circulatory shock, overwhelming infections, multiple organ failure, refractory hypoxia, or catastrophic device failure. In all other situations, deactivating the LVAD/TAH is itself the lethal pathophysiology and the proximate cause of death. We postulate that the onset of new lethal pathophysiology is the determinant factor in judging the permissibility of the life-ending discontinuation of a durable MCS.

Published literature have not discerned end-of-life palliative versus life-shortening effects of pharmacologically maintaining continuous deep sedation until death (ie, dying in deep sleep) compared with common sedation practices relieving distress in the final conscious phase of dying. Continuous deep sedation predictably suppresses brainstem vital centers and shortens life. Continuous deep sedation remains controversial as palliation for existential suffering and in elective death requests by discontinuation of chronic ventilation or circulatory support with mechanical devices. Continuous deep sedation contravenes the double-effect principle because: (1) it induces permanent coma (intent of action) for the contingency relief of suffering and for social isolation (desired outcomes) and (2) because of its predictable and proportional life-shortening effect. Continuous deep sedation should be distinguished from common sedation practices for palliation and characterized instead as physician-assisted death.

To shorten the transplantation waiting time in the United States, federal regulations have been introduced requiring hospitals to develop policies for organ donation after cardiac (or circulatory) death (DCD). The practice of DCD is invoked based on the validity of the University of Pittsburgh Medical Center (UPMC) protocol and relies on the accuracy of the University of Wisconsin (UW) evaluation tool to appropriately identify organ donors. There is little evidence to support the position that the criteria for organ procurement adopted from the UPMC protocol complies with the dead donor rule. A high false-positive rate of the UW evaluation tool can expose many dying patients to unnecessary perimortem interventions because of donation failure. The medications and/or interventions for the sole purpose of maintaining organ viability can have unintended negative consequences on the timing and quality of end-of-life care offered to organ donors. It is essential to address and manage the evolving conflict between optimal end-of-life care and the necessary sacrifices for the procurement of transplantable organs from the terminally ill. The recipients of marginal organs recovered from DCD can also suffer higher mortality and morbidity than recipients of other types of donated organs. Finally, transparent disclosure to the public of the risks involved to both organ donors and recipients may contribute to open societal debate on the ethical acceptability of DCD.