在生命末期患者照护中，如何缓解患者的躯体性痛苦已取得巨大进展，有相当成熟的治疗方法，如何恰当且有效地处理晚期和渐进性疾病给患者带来的存在性痛苦成为了新的严峻挑战。尽管文献资料有限，但在我国也有使用安宁镇静处理存在性痛苦的病例报告，也有医生在关注终末期患者的安宁镇静治疗时关注到了处理存在性痛苦的伦理问题，体现了我国存在处理存在性痛苦的实际需求，照料存在性痛苦是临床工作中的一部分。对某一疾病或症状应当采取何种医疗干预措施，不仅是科学问题，同时也是伦理问题。在痛苦症状的常规干预和标准治疗药物失败时，采用安宁镇静可以达到控制症状和缓解痛苦的目的，但仅凭有效性难以为这一方案提供充分的支持。安宁镇静有意地通过降低患者意识程度的方式来使患者对痛苦不敏感，这种方式引起了许多伦理争论。学者们基于不同的立场，就是否应使用安宁镇静处理存在性痛苦（palliative sedation for existential suffering，PS-ES）的问题，进行了深入的论证，但是这些论证没有得到充分的梳理、整合，没有反映在临床指南当中。对于患者和负责任的、致力于为患者提供富有同情心的帮助与支持的医护团队及患者家属来说，伦理论证同有效的科学证据一样为正确的临床决策提供着必不可少的支持。

因此，本文对关于PS-ES这一方案的伦理学研究与讨论进行叙述性综述，按照从概念到哲学和伦理理论再到伦理原则的逻辑次序，梳理PS-ES在伦理上是否应当或可接受的讨论、相关的伦理学理论和伦理框架下有关本文论题的论证、以及伦理上接受PS-ES的条件，为临床决策提供伦理支持。概念方面的讨论主要集中在存在性痛苦概念的内涵和临床价值，安宁镇静作为临床术语的合理性及其与安乐死的关系。哲学和伦理学方面的讨论主要集中在支持与反对PS-ES的理由是否能与普遍接受的医学哲学理论和伦理学理论保持一致性。生命伦理学的经典基本原则，尊重、有益和不伤害、公正是讨论伦理问题，指导和评价行动所依据的最基础的伦理框架，也是在讨论PS-ES时，最为普遍应用的伦理原则。在既存的不同观点中，PS-ES的支持方，也认为能够得到支持的PS-ES应该与其他医疗干预一样遵循医疗实践的规范性原则，包括相称性、恢复性、整体性、适度性和审慎性原则。

In the end of life care, great progress has been made in alleviating the somatic pain of patients, and how to deal with the existential suffering caused by advanced and progressive diseases properly and effectively has become a great new challenge. Although the literature is limited, there are also some cases reported in our country that use palliative sedation to deal with the existential suffering, and some doctors pay attention to the ethical problem of dealing with the existential suffering when paying attention to the palliative sedation treatment of end-of-life patients, which represents the actual need to deal with the existential suffering in our country. What kind of medical intervention should be taken for a disease or symptom is not only a scientific problem, but also an ethical one. When routine interventions for suffering symptoms and standard therapeutic drugs fail, the use of palliative sedation can achieve the purpose of controlling symptoms and relieving suffering, but effectiveness alone makes it difficult to provide adequate support for this treatment. Palliative sedation intentionally cause insensitivity to suffering by reducing the patient's awareness, which has caused many ethical debates. Based on different positions, scholars have conducted thoughtful arguments on whether to use palliative sedation for existential suffering（PS-ES), but these arguments have not been fully combed, integrated, and reflected in clinical guidelines.For patients and their families and responsible health care teams dedicated to providing compassionate help and support to patients, ethical arguments, like valid scientific evidence, provide essential support for correct clinical decision-making. 

Therefore, this article reviews the ethical research and discussion about PS-ES, according to the logical order from concept to philosophy and ethics theory to ethics principle, combs the ethical debate regards whether the PS-ES should or can be conducted, the related ethics theory and the ethical framework related to these arguments, as well as the condition of ethical justifiable PS-ES, provides the ethical support for the clinical decision making. The conceptual debate mainly focuses on the meaning and medical value of existential suffering, the appropriateness of palliative sedation as a term and its relationship with euthanasia. Arguments in theory have focused on whether the reasons for supporting and opposing PS-ES are consistent with the more generally accepted theories of medical philosophy and ethics.The classical principles of bioethics, autonomy, beneficence/maleficence, and justice are the most basic ethical framework for discussing ethical issues, guiding and evaluating actions, and therefore the most widely applied ethical principles when discussing PS-ES. Of the different views that exist, who support PS-ES also think it should follow the normative principles of medical practice, as with other medical interventions, including the principles of proportionality, restoration, integrity, moderation and prudence.