Variation in donation after circulatory death hospital policies in a single donor service area

Knowledge gaps in heart and lung donation after the circulatory determination of death: Report of a workshop of the National Heart, Lung, and Blood Institute

In a workshop sponsored by the U.S. National Heart, Lung, and Blood Institute, experts identified current knowledge gaps and research opportunities in the scientific, conceptual, and ethical understanding of organ donation after the circulatory determination of death and its technologies. To minimize organ injury from warm ischemia and produce better recipient outcomes, innovative techniques to perfuse and oxygenate organs postmortem in situ, such as thoracoabdominal normothermic regional perfusion, are being implemented in several medical centers in the US and elsewhere. These technologies have improved organ outcomes but have raised ethical and legal questions. Re-establishing donor circulation postmortem can be viewed as invalidating the condition of permanent cessation of circulation on which the earlier death determination was made and clamping arch vessels to exclude brain circulation can be viewed as inducing brain death. Alternatively, TA-NRP can be viewed as localized in-situ organ perfusion, not whole-body resuscitation, that does not invalidate death determination. Further scientific, conceptual, and ethical studies, such as those identified in this workshop, can inform and help resolve controversies raised by this practice.

Ethical Issues in Donation following Circulatory Death: A Scoping Review Examining Changes over Time from 1993 to 2022

Background: Ethical frameworks for organ donation following circulatory death (DCD) were established >20 years ago. However, considerable variation exists among these, indicating consensus has not been reached on all issues. Additionally, advances such as cardiac DCD transplants and normothermic regional perfusion (NRP) may have reignited old debates.Methods: We reviewed the English-language literature addressing ethical issues in DCD from 1993 to 2022, examining changes in frequency with which ethical principles and their sub-themes identified within each, were addressed.Results: Non-maleficence was the most frequently addressed principle (192 of 199 articles), as well as the most varied, with 9 subthemes (versus 2-4 within each of the other bioethical principles).Conclusions: There were several changes in the terminology used to refer to DCD over time, and substantial interest in cardiac DCD and NRP in recent publications, arising in 11 and 19 of the 30 publications from 2018 to 2022.

Brain-based arterial pulse pressure threshold for death determination: a systematic review

PURPOSE

There is lack of consensus regarding the minimum arterial pulse pressure required for confirming permanent cessation of circulation for death determination by circulatory criteria in organ donors. We assessed direct and indirect evidence supporting whether one should use an arterial pulse pressure of 0 mm Hg vs more than 0 (5, 10, 20, 40) mm Hg to confirm permanent cessation of circulation.

SOURCE

We conducted this systematic review as part of a larger project to develop a clinical practice guideline for death determination by circulatory or neurologic criteria. We systematically searched Ovid MEDLINE, Ovid Embase, Cochrane Central Register of Controlled Trials (CENTRAL) via the Cochrane Library, and Web of Science for articles published from inception until August 2021. We included all types of peer-reviewed original research publications related to arterial pulse pressure as monitored by an indwelling arterial pressure transducer around circulatory arrest or determination of death with either direct context-specific (organ donation) or indirect (outside of organ donation context) data.

PRINCIPAL FINDINGS

A total of 3,289 abstracts were identified and screened for eligibility. Fourteen studies were included; three from personal libraries. Five studies were of sufficient quality for inclusion in the evidence profile for the clinical practice guideline. One study measured cessation of cortical scalp electroencephalogram (EEG) activity after withdrawal of life-sustaining measures and showed that EEG activity fell below 2 μV when the pulse pressure reached 8 mm Hg. This indirect evidence suggests there is a possibility of persistent cerebral activity at arterial pulse pressures > 5 mm Hg.

CONCLUSION

Indirect evidence suggests that clinicians may incorrectly diagnose death by circulatory criteria if they apply any arterial pulse pressure threshold of greater than 5 mm Hg. Moreover, there is insufficient evidence to determine that any pulse pressure threshold greater than 0 and less than 5 can safely determine circulatory death.

STUDY REGISTRATION

PROSPERO (CRD42021275763); first submitted 28 August 2021.