Palliative sedation: welcome guidance on a controversial issue.

Palliative sedation (PS) is the use of medications to reduce consciousness for the relief of intolerable and refractory symptoms, in patients with limited life expectancy. The ethical justification of palliative sedation is based upon the principles of double effect, autonomy and proportionality. Double effect is predicated upon the primary intent being to relieve suffering, despite potential foreseeable, but unintended, adverse effects. Proportionality is based upon the use of PS in the face of intolerable distress as a ‘therapy of last resort’, when all other potentially less harmful options have been expended or are inappropriate. PS is neither slow euthanasia nor physician-assisted suicide. Both of these practices involve the specific intent to end life, the deliberate use of lethal doses of sedation drugs, or non-therapeutic escalation of doses disproportionate to symptom distress. PS does not shorten life overall (when implemented in specialist palliative care units), despite the expected risk of individual complications (e.g. respiratory or hemodynamic compromise, aspiration, or venous thromboembolism). Sedative drugs first appeared in modern medicine in the 19th century, with bromide and chloral hydrate. Barbiturates were introduced in 1903, and benzodiazepines in 1959. The first descriptions of sedation for symptom control in advanced disease were published in 1990–1991. The early literature described a wide range in prevalence, indications and clinical practices. The prevalence in these reports ranged from 16% to over 50%. Indications included agitation and restlessness, pain, delirium, respiratory distress, myoclonus, and psychological symptoms. Drugs used for sedation included benzodiazepines, antipsychotics and barbiturates. Despite a number of prospective studies and published guidelines, evidence upon which to base practice has remained limited and controversial issues persist. These include almost every aspect of PS; the definition and terminology (palliative versus terminal), the types of sedation included under this term (intermittent versus continuous, light versus deep), the indications (physical or existential distress), the use of artificial hydration and nutrition, and the ethical basis and differentiation from euthanasia. Decisions about palliative sedation are complex and can have significant implications for the patient and lasting impact on family and staff. Staff need to develop awareness of their own preferences about care of the dying, and the potential role of frustration, sense of failure and burnout in decision making. Individual physician personal and professional factors may influence the practice of PS, including prevalence, determination of refractoriness, level of sedation used, and drugs employed. Families and staff need extensive support to understand the decision-making process, and be clear about the goals and expected outcomes. Identifying a family spokesperson (preferably one chosen by the patient) may help communication, especially for large, geographically scattered or conflicted families. Without effective communication families may be left with feelings of profound confusion, guilt or remorse, which complicate their subsequent bereavement. For these reasons evaluation and decision making by a multidisciplinary team skilled in palliative care is essential prior to initiating PS. Initiating PS without palliative medicine involvement is potentially hazardous. Palliative medicine consultation has been demonstrated to elicit previously undocumented diagnoses (especially delirium), and suggest multiple management strategies in advanced cancer, even within tertiary cancer centers. A dilemma in decision making arises where there is a lack of access to, or awareness of, specialized interventions including palliative medicine, psychiatry, interventional pain management, and spiritual care. Non-palliative medicine physicians need to have insight into their own therapeutic limitations, whilst palliative medicine physicians should be available to provide support via telephone or videoconference to isolated clinicians.