Palliative Sedation for Existential Suffering: A Systematic Review of Argument-Based Ethics Literature

Abstract

Context: Although unanimity exists on using palliative sedation (PS) for controlling refractory physical suffering in end-of-life situations, using it for controlling refractory existential suffering (PS-ES) is controversial. Complicating the debate is that definitions and terminology for existential suffering are unclear, ambiguous, and imprecise, leading to a lack of consensus for clinical practice.

Objectives: To systematically identify, describe, analyze, and discuss ethical arguments and concepts underpinning the argument-based bioethics literature on PS-ES.

Methods: We conducted a systematic search of the argument-based bioethics literature in PubMed, CINAHL, Embase^®, The Philosopher's Index, PsycINFO^®, PsycARTICLES^®, Scopus, ScienceDirect, Web of Science, Pascal-Francis, and Cairn. We included articles published in peer-reviewed journals till December 31, 2016, written in English or French, which focused on ethical arguments related to PS-ES. We used Peer Review of Electronic Search Strategies protocol, Preferred Reporting Items for Systematic Reviews and Meta-Analyses, and The Qualitative Analysis Guide of Leuven for data extraction and synthesis of themes.

Results: We identified 18 articles that met the inclusion criteria. Our analysis revealed mind-body dualism, existential suffering, refractoriness, terminal condition, and imminent death as relevant concepts in the ethical debate on PS-ES. The ethical principles of double effect, proportionality, and the four principles of biomedical ethics were used in argumentations in the PS-ES debate.

Conclusion: There is a clear need to better define the terminology used in discussions of PS-ES and to ground ethical arguments in a more effective way. Anthropological presuppositions such as mind-body dualism underpin the debate and need to be more clearly elucidated using an interdisciplinary approach.

Keywords: Systematic review; deep sedation; end-of-life care; ethics; existential suffering; palliative sedation.