ADDRESSING CHALLENGES WITH SEDATION IN END-OF-LIFE CARE

Abstract

In 2009, Quill and colleagues stipulated that there are three types of sedation practices at the end of life: ordinary sedation, proportionate palliative sedation (PPS), and palliative sedation to unconsciousness (PSU). Of the three, PPS and PSU are described as “last-resort options” to relieve refractory symptoms, and PSU as the most ethically controversial type that “should be quite rare.” Unfortunately, little is known about actual sedation practices at the end of life in the United States. This may be due in part to a lack of conceptual clarity about sedation in end-of-life care. We argue that, until more is known about what sedation practices occur at the end of life, and how practices can be improved by research and more specific guidelines, “palliative sedation” will remain more misunderstood and controversial than it might otherwise be. In our view, overcoming the challenges posed by sedation in end-of-life care requires: 1) greater specificity regarding clinical situations and approaches to sedation, 2) research tailored to focused clinical questions, and 3) improved training and safeguards in sedation practices. Terms like PPS and PSU are relatively simple to understand in the abstract, but their application comprises various clinical situations and approaches to sedation. An obvious barrier to empirical research on sedation practices in end-of-life care is the challenge of determining these elements, especially if not clearly communicated. Additionally, we argue that training for palliative care specialists and others should include monitoring and rescue techniques as required competencies.

The National Hospice and Palliative Care Organization (NHPCO) broadly defines palliative sedation as “the lowering of patient consciousness using medications for the express purpose of limiting patient awareness of suffering that is intractable and intolerable.”¹ Yet, what this means in practice, how clinicians use the term, and which interventions the term includes and which it does not, remain unclear.

Quill and colleagues attempted to clarify the types of sedation used in end-of-life care and explain how the most ethically controversial practices should be rare.² They stipulated that there are three types of sedation: 1) ordinary sedation, an everyday practice in which “the goal of treatment is relief of the symptom without reducing the patient’s level of consciousness”; 2) proportionate palliative sedation (PPS), in which “increasing levels of sedation” are used “in response to otherwise intractable physical suffering in imminently dying persons…or for agitated terminal delirium”; and 3) palliative sedation to unconsciousness (PSU), in which “unconsciousness is the intended goal of the sedation” in order to relieve otherwise intolerable suffering, usually in imminently dying patients but sometimes for existential suffering or the patient’s “need for control.” Of these types of sedation, PPS and PSU are both described as “last-resort options” and PSU as the most ethically controversial type that “should be quite rare.”

Data regarding real-life practices of sedation in end-of-life care are largely from outside the United States, heterogeneous, and challenging to interpret because of variability in definitions used and approaches described.^3–5 Within the United States, one prospective study involving patients with advanced cancer found chlorpromazine safe and effective for relief of terminal restlessness and dyspnea.⁶ One chart review study estimated that 15% of patients admitted to an academic palliative care unit received some form of palliative sedation.⁷ Another chart review study found that 2% of patients enrolled in a hospice program received phenobarbital suppositories for palliative sedation at home.⁸ Some authors suggest that a lack of conceptual clarity about sedation in end-of-life care has impeded research and practice standard development.^3,5

We argue that, until more is known about what sedation practices occur at the end of life, and how these practices can be improved by further research and more specific guidelines, the concept of “palliative sedation” will remain more misunderstood and controversial than it might otherwise be. The newly revised 2023 European Association for Palliative Care (EAPC) framework for palliative sedation provides a relevant precedent and suggests the need for an updating of the NHPCO guidelines—bearing in mind that practices and recommendations in the United States may differ from those in Europe.⁹ We propose that overcoming the challenges posed by sedation in end-of-life care requires: 1) greater specificity regarding clinical scenarios and approaches to sedation, 2) research tailored to focused clinical questions, and 3) improved training and safeguards in sedation practices.

The Need for Specificity

Terms like PPS and PSU are relatively simple to understand in the abstract, but their application comprises a variety of clinical situations and approaches to sedation. The unifying feature for both PPS and PSU is the clinician’s intention: for PPS, the goal of sedation is to lower the patient’s consciousness with “the minimum amount of sedation needed” to relieve suffering; and for PSU, the goal of sedation is to render the patient unconscious as a means to relieve or avoid suffering.² In the United States, double effect reasoning—which critically distinguishes between what one foresees and intends—is often invoked as an ethical foundation for PPS, but not PSU.^2,10 By contrast, in Canada and Europe, advocates of PPS and PSU more typically appeal to proportionality between the level of sedation and degree of suffering.^9,11,12

Although intention is a key element in ethical considerations of sedation practices, the clinical rationale for and specific approach to sedation are closely linked to intention and form a necessary basis for evaluating it. An obvious barrier to empirical research on sedation practices in end-of-life care is the challenge of determining these related elements, especially if not clearly communicated. Another challenge is determining the degree and duration of lowered consciousness attained with sedation, especially if this is not assessed using standard measures.

In discussions of sedation practices at the end of life, greater specificity regarding the rationale for and approach to sedation is necessary for ethical considerations of these practices. To give an example of the need for specificity, one systematic review on sedation practices in end-of-life care showed that delirium was the most common “refractory symptom” requiring sedation across ten studies, comprising 54% of the patients, whereas dyspnea and pain were less common indications (30% and 17% of patients, respectively).⁴ However, the studies in question did not specify how refractoriness was determined and how sedation was used in each case.

Clinical management of delirium at the end of life involves both complexity and uncertainty.¹³ For example, two possible approaches to sedation for patients with delirium may involve significant ethical differences: temporary sedation to treat symptoms of delirium while pursuing a workup for underlying causes, and continuous sedation until death for a patient determined to have terminal delirium. By contrast, sedation for patients with dyspnea or pain may involve different considerations in the determination of refractoriness and approaches to sedation.⁴

The Need for Research

Most studies on sedation practices at the end of life provide general overviews of reasons for sedation, the types of sedatives used, and the modes and duration of sedation. However, few studies consider variations in sedation practices based on the underlying reason for sedation.¹⁴ Research on sedation at the end of life should be less generalizing and more contextualized to specific indications and approaches.

Since the literature suggests that delirium is the most common reason for sedation at the end of life,⁴ a priority for research should be to focus on key clinical questions surrounding the diagnosis and management of delirium.¹⁵ These questions include how to distinguish between pre-terminal and terminal delirium, how to determine whether the symptoms of delirium are “refractory” and sedation is indicated, which sedatives are most effective for symptom relief without worsening delirium, and what is the optimal depth and duration of sedation.

Research related to other reasons for sedation—such as dyspnea, pain, and psychological distress—should similarly focus on questions surrounding the symptoms and their management.⁴ A fundamental question underlying cases in which sedation is being considered is how to decide when a symptom or symptoms are considered “refractory.” For instance, as the EAPC previously observed in its 2009 framework, “Given the subjectivity of refractoriness and the profound interindividual variability of responsiveness to palliative interventions, these assessments are often very difficult to make.”¹⁶ In its 2023 framework, the EAPC still acknowledges that “the complexity of assessing refractory symptoms…remain[s] under debate.”⁹

The Need for Training and Safeguards

Quill and colleagues have called for education about PPS and PSU as a training requirement for palliative care specialists and other clinicians who care for seriously ill patients.² Currently, fellows in hospice and palliative medicine must demonstrate competence in palliative sedation as one of the “key events in patient care.”¹⁷ However, approaches to training and evaluation for this competency would necessarily be limited by the general nature of existing organizational guidelines; for instance, the NHPCO, in its position statement on palliative sedation, states that “it is beyond the purview of this organization to make pharmacologic recommendations.”¹ In light of the 2023 EAPC framework, which draws on recent studies to suggest a stepwise approach to the use of specific drugs to achieve varying degrees of sedation,⁹ it may be appropriate for the NHPCO to consider similarly engaging with the literature in an update of its own guidelines—although data on practices in the United States remain limited.

Regarding appropriate safeguards for sedation practices at the end of life, it may be helpful to look to other fields of medicine with more extensive experience in sedation techniques. The American Society of Anesthesiologists, for example, in their practice guidelines for sedation by non-anesthesiologists, provides the following caution: “Because sedation is a continuum, it is not always possible to predict how an individual patient will respond. Hence, practitioners intending to produce a given level of sedation should be able to rescue patients whose level of sedation becomes deeper than initially intended.”¹⁸ With this in mind, training for palliative care specialists and others should include monitoring and rescue techniques as a required competency. The EAPC framework for use of sedation in palliative care refers to the potential need for reversal of sedation and provides examples of scales to monitor patients with lowered consciousness, including the Richmond agitation sedation scale.¹⁶

Conclusion

Improving sedation practices at the end of life requires greater specificity with respect to clinical applications, more focused research, and clearer training and safety standards. With greater clarity about the clinical reasons for and specific approaches to sedation—supported by a strengthened evidence base—clinicians will be in a better position to optimally care for their patients at the end of life.