Cellular recovery after prolonged warm ischaemia of the whole body.

After cessation of blood flow or similar ischaemic exposures, deleterious molecular cascades commence in mammalian cells, eventually leading to their death1,2. Yet with targeted interventions, these processes can be mitigated or reversed, even minutes or hours post mortem, as also reported in the isolated porcine brain using BrainEx technology3. To date, translating single-organ interventions to intact, whole-body applications remains hampered by circulatory and multisystem physiological challenges. Here we describe OrganEx, an adaptation of the BrainEx extracorporeal pulsatile-perfusion system and cytoprotective perfusate for porcine whole-body settings. After 1 h of warm ischaemia, OrganEx application preserved tissue integrity, decreased cell death and restored selected molecular and cellular processes across multiple vital organs. Commensurately, single-nucleus transcriptomic analysis revealed organ- and cell-type-specific gene expression patterns that are reflective of specific molecular and cellular repair processes. Our analysis comprises a comprehensive resource of cell-type-specific changes during defined ischaemic intervals and perfusion interventions spanning multiple organs, and it reveals an underappreciated potential for cellular recovery after prolonged whole-body warm ischaemia in a large mammal.

Restoration of brain circulation and cellular functions hours post-mortem.

The brains of humans and other mammals are highly vulnerable to interruptions in blood flow and decreases in oxygen levels. Here we describe the restoration and maintenance of microcirculation and molecular and cellular functions of the intact pig brain under ex vivo normothermic conditions up to four hours post-mortem. We have developed an extracorporeal pulsatile-perfusion system and a haemoglobin-based, acellular, non-coagulative, echogenic, and cytoprotective perfusate that promotes recovery from anoxia, reduces reperfusion injury, prevents oedema, and metabolically supports the energy requirements of the brain. With this system, we observed preservation of cytoarchitecture; attenuation of cell death; and restoration of vascular dilatory and glial inflammatory responses, spontaneous synaptic activity, and active cerebral metabolism in the absence of global electrocorticographic activity. These findings demonstrate that under appropriate conditions the isolated, intact large mammalian brain possesses an underappreciated capacity for restoration of microcirculation and molecular and cellular activity after a prolonged post-mortem interval.

Research opportunities and ethical considerations for heart and lung xenotransplantation research: A report from the National Heart, Lung, and Blood Institute workshop.

Xenotransplantation offers the potential to meet the critical need for heart and lung transplantation presently constrained by the current human donor organ supply. Much was learned over the past decades regarding gene editing to prevent the immune activation and inflammation that cause early organ injury, and strategies for maintenance of immunosuppression to promote longer-term xenograft survival. However, many scientific questions remain regarding further requirements for genetic modification of donor organs, appropriate contexts for xenotransplantation research (including nonhuman primates, recently deceased humans, and living human recipients), and risk of xenozoonotic disease transmission. Related ethical questions include the appropriate selection of clinical trial participants, challenges with obtaining informed consent, animal rights and welfare considerations, and cost. Research involving recently deceased humans has also emerged as a potentially novel way to understand how xeno-organs will impact the human body. Clinical xenotransplantation and research involving decedents also raise ethical questions and will require consensus regarding regulatory oversight and protocol review. These considerations and the related opportunities for xenotransplantation research were discussed in a workshop sponsored by the National Heart, Lung, and Blood Institute, and are summarized in this meeting report.

Research involving the recently deceased: ethics questions that must be answered.

Research involving recently deceased humans that are physiologically maintained following declaration of death by neurologic criteria-or 'research involving the recently deceased'-can fill a translational research gap while reducing harm to animals and living human subjects. It also creates new challenges for honouring the donor's legacy, respecting the rights of donor loved ones, resource allocation and public health. As this research model gains traction, new empirical ethics questions must be answered to preserve public trust in all forms of tissue donation and in the practice of medicine while respecting the legacy of the deceased and the rights of donor loved ones. This article suggests several topics for immediate investigation to understand the attitudes and experiences of researchers, clinical collaborators, donor loved ones and the public to ensure research involving the recently deceased advances ethically.

Reflections on New Evidence on Crisis Standards of Care in the COVID-19 Pandemic.

Crisis standards of care have been widely developed by healthcare systems and states in the United States during the COVID-19 pandemic, and in some rare cases have actually been used to allocate medical resources. All publicly available U.S. crisis standards of care with a mechanism for allocating scarce resources make use of the Sequential Organ Failure Assessment (SOFA) score in hopes of assigning scarce resources to those patients who are more likely to survive. We reflect on the growing body of evidence suggesting that the SOFA score has limited accuracy in predicting mortality among patients hospitalized with COVID-19 and that the SOFA score systematically disfavors Black patients. Use of the SOFA score for allocating scarce resources may therefore result in Black patients with equal likelihood of survival being deprived of life-saving medical resources. There is also a risk of injustice for patients with non-COVID-19 diagnoses, for whom the SOFA score may be a more accurate prognostic score, but who might nevertheless be unfairly (de)prioritized when assessed alongside COVID-19 patients using the same scoring system. For these reasons we recommend that the SOFA score not be used for triage purposes during the COVID pandemic, and that a national effort be made to develop and empirically test crisis standards of care in advance of the next public health emergency.

Addressing Ethical Challenges in US-Based HIV Phylogenetic Research.

In recent years, phylogenetic analysis of HIV sequence data has been used in research studies to investigate transmission patterns between individuals and groups, including analysis of data from HIV prevention clinical trials, in molecular epidemiology, and in public health surveillance programs. Phylogenetic analysis can provide valuable information to inform HIV prevention efforts, but it also has risks, including stigma and marginalization of groups, or potential identification of HIV transmission between individuals. In response to these concerns, an interdisciplinary working group was assembled to address ethical challenges in US-based HIV phylogenetic research. The working group developed recommendations regarding (1) study design; (2) data security, access, and sharing; (3) legal issues; (4) community engagement; and (5) communication and dissemination. The working group also identified areas for future research and scholarship to promote ethical conduct of HIV phylogenetic research.

The ethics of testing and research of manufactured organs on brain-dead/recently deceased subjects.

Over 115 000 people are waiting for life-saving organ transplants, of whom a small fraction will receive transplants and many others will die while waiting. Existing efforts to expand the number of available organs, including increasing the number of registered donors and procuring organs in uncontrolled environments, are crucial but unlikely to address the shortage in the near future and will not improve donor/recipient compatibility or organ quality. If successful, organ bioengineering can solve the shortage and improve functional outcomes. Studying manufactured organs in animal models has produced valuable data, but is not sufficient to understand viability in humans. Before risking manufactured organ experimentation in living humans, study of bioengineered organs in recently deceased humans would facilitate evaluation of the function of engineered tissues and the complex interactions between the host and the transplanted tissue. Although such studies do not pose risk to human subjects, they pose unique ethical challenges concerning the previous wishes of the deceased, rights of surviving family members, effective operation and fair distribution of medical services, and public transparency. This article investigates the ethical, legal and social considerations in performing engineered organ research on the recently deceased.

Developing a Triage Protocol for the COVID-19 Pandemic: Allocating Scarce Medical Resources in a Public Health Emergency.

The coronavirus disease-2019 (COVID-19) has caused shortages of life-sustaining medical resources, and future waves of the virus may cause further scarcity. The Yale New Haven Health System developed a triage protocol to allocate scarce medical resources during the COVID-19 pandemic, with the primary goal of saving the most lives possible, and a secondary goal of making triage assessments and decisions consistent, transparent, and fair. We outline the process of developing the triage protocol, summarize the protocol itself, and discuss the major ethical challenges encountered, along with our answers to these challenges. These challenges include (1) the role of age and chronic comorbidities; (2) evaluating children and pregnant patients; (3) racial, ethnic, and socioeconomic disparities in health; (4) prioritization of healthcare workers; and (5) balancing clinical judgment versus protocolized assessments. We conclude with a review of the limitations of our protocol and the lessons learned. We hope that a robust public discussion of such protocols and the ethical challenges that they raise will result in the fairest possible processes, less need for triage, and more lives saved during future waves of the COVID-19 pandemic and similar public health emergencies.

Maximizing biomedical research impacts through bioethical considerations.

Bioethics is the formal study of ethical judgments concerning the advances and applications of biology, medicine and related technologies. In a time of unprecedented biomedical advances, it is critical to integrate bioethical frameworks more fully into biomedical research to align these scientific advances with their intended societal needs. In this Perspective, we describe some motivations and frameworks for cross-disciplinary bioethical training for biomedical researchers, and discuss how actively considering bioethics in research and study design could maximize biomedical researchers' intended impacts in society.

A randomized clinical trial assessing the effect of automated medication-targeted alerts on acute kidney injury outcomes.

Acute kidney injury is common among hospitalized individuals, particularly those exposed to certain medications, and is associated with substantial morbidity and mortality. In a pragmatic, open-label, National Institutes of Health-funded, parallel group randomized controlled trial (clinicaltrials.gov NCT02771977), we investigate whether an automated clinical decision support system affects discontinuation rates of potentially nephrotoxic medications and improves outcomes in patients with AKI. Participants included 5060 hospitalized adults with AKI and an active order for any of three classes of medications of interest: non-steroidal anti-inflammatory drugs, renin-angiotensin-aldosterone system inhibitors, or proton pump inhibitors. Within 24 hours of randomization, a medication of interest was discontinued in 61.1% of the alert group versus 55.9% of the usual care group (relative risk 1.08, 1.04 - 1.14, p = 0.0003). The primary outcome - a composite of progression of acute kidney injury, dialysis, or death within 14 days - occurred in 585 (23.1%) of individuals in the alert group and 639 (25.3%) of patients in the usual care group (RR 0.92, 0.83 - 1.01, p = 0.09). Trial Registration Clinicaltrials.gov NCT02771977.