Abstract

• Some terminally ill patients experience unbearable distress, due to pain, dyspnoea, confusion, anxiety and/or depression, despite the best available treatments. One effective way of relieving this distress is to reduce the patient's level of consciousness.
   
• What are the principles, practices and ethics of palliative sedation in distressed terminally ill patients? To answer this question, we reviewed the relevant literature using the standard Prescrire methodology.
   
• Sedation may be envisaged when death is imminent, when suffering is unbearable and refractory to standard treatments, or when available treatments are ineffective, too slow to act, or have unacceptable adverse effects. Before opting for terminal palliative sedation, it is important to ensure there is no reversible underlying cause.
  In other situations, temporary "respite" sedation may be warranted, while waiting for other treatments to take effect, for example.
   
• The patient's consent should be obtained before starting palliative sedation. If this is not possible, the situation should be discussed with a legally designated proxy, or with the patient's loved ones.
   
• The sole aim of palliative sedation is to relieve the patient's distress. Sedation generally has no effect on survival time, but it may hasten death by inducing respiratory depression or haemodynamic instability. Adjustment of drug doses should be based on several parameters in case of respite sedation.
   
• Midazolam, a benzodiazepine, is the sedative of choice in this setting, because of its pharmacological properties, including a rapid onset of action, reversibility, and availability of various injectable forms. A phenothiazine neuroleptic (especially levomepromazine) is an alternative, especially in case of confusion with episodes of delirium. Paradoxical agitation and respiratory and/or cardiovascular depression are the main adverse effects.
   
• The prescribing physician must be present at the beginning of palliative sedation, to show that she or he endorses the decision, and to manage untoward events. The dose regimen should be adapted to the degree of relief obtained, and not simply the level of consciousness.
   
• Morphine is not to be used as a sedative, but ongoing morphine treatment should be continued for its analgesic effect (and to avoid a withdrawal syndrome).
   
• Before beginning continuous palliative sedation, a decision should be made about whether to continue or withdraw hydration, if possible after consulting the patient, or else a legally designated proxy. Lack of hydration hastens death, but does not increase suffering. Hydration delays death and can aggravate some disorders.
   
• The decision to begin terminal sedation is difficult, as the patient will no longer be able to interact with his or her loved ones; it should only be taken when the patient is in extreme distress. Other than the practical aim of calming the patient without hastening death, sedation should respect the patient's wishes, as expressed by the patient or the legally designated proxy and loved ones. All those close to the patient, family and caregivers, should be informed of the decision and its consequences. 

©Prescrire 1 January 2012

"Sedation at end of life. When distress is unbearable despite treatment" Prescrire Int 2012; 21 (123): 16-20. (Pdf, subscribers only)