Continuous palliative sedation therapy.

Although there are various types of sedation, including intermittent and respite sedation, and sedation as a side effect of medications such as opioids,2 continuous palliative sedation therapy (CPST) at or near the end of life is the focus of this article. Continuous palliative sedation therapy is the use of ongoing sedation for symptom management, considered during the end of life when a patient is close to death (ie, within hours or days3 or up to the last 2 weeks of life1) and continued until the patient’s death. Palliative sedation should be a last resort for patients who have intolerable, refractory symptoms.3 The term refractory describes a symptom that “cannot be adequately controlled despite aggressive efforts to identify a tolerable therapy that does not compromise consciousness.”4 Health care providers, including family physicians, might be uncomfortable with CPST owing to unfamiliarity, differing terminology (eg, previous use of the term terminal sedation5), ethical and legal challenges,6 and misconceptions about it being a form of euthanasia or physician-assisted suicide.2,5,7,8 Consultation with a physician who has knowledge of and expertise in both symptom management and CPST is strongly advised when considering CPST.1,6 Interprofessional team members, where available, can provide valuable input and important assistance with decision making regarding CPST.3 Two of the most common indications for CPST, nonreversible refractory agitated delirium and refractory and intolerable dyspnea,2,3 are the focus of this article. The use of CPST when symptoms are nonphysical (eg, existential distress) remains controversial2,9 and is not discussed. Similarly, initiation, continuation, or discontinuation of hydration and artificial feeding should be considered separate issues3 and are also not discussed. Owing to the lack of randomized controlled trials and the differences in clinical settings and types of medications used, there is no evidence for the recommendation of one particular medication over another for CPST.2,3 However, sedating neuroleptic or antipsychotic medications and benzodiazepines are the most commonly used, while barbiturates and propofol are used only occasionally1,3,7 In general, the lowest necessary level of sedation to provide adequate relief of suffering,3 or proportionate sedation, should be implemented. It is important to note that opioids should not be used for palliative sedation, as the high doses required for sedation will inevitably lead to opioid-induced neurotoxicity and possible respiratory depression.1,7 However, they should be continued if used to manage other symptoms such as pain and dyspnea.