Palliative sedation in end-of-life care and survival: a systematic review

Palliative sedation is a clinical procedure aimed at relieving refractory symptoms in patients with advanced cancer. It has been suggested that sedative drugs may shorten life, but few studies exist comparing the survival of sedated and nonsedated patients. We present a systematic review of literature on the clinical practice of palliative sedation to assess the effect, if any, on survival.

A systematic review of literature published between January 1980 and December 2010 was performed using MEDLINE and EMBASE databases. Search terms included palliative sedation, terminal sedation, refractory symptoms, cancer, neoplasm, palliative care, terminally ill, end-of-life care, and survival. A manual search of the bibliographies of electronically identified articles was also performed.

Eleven published articles were identified describing 1,807 consecutive patients in 10 retrospective or prospective nonrandomized studies, 621 (34.4%) of whom were sedated. One case-control study was excluded from prevalence analysis. The most frequent reason for sedation was delirium in the terminal stages of illness (median, 57.1%; range, 13.8% to 91.3%). Benzodiazepines were the most common drug category prescribed. Comparing survival of sedated and nonsedated patients, the sedation approach was not shown to be associated with worse survival.

Even if there is no direct evidence from randomized clinical trials, palliative sedation, when appropriately indicated and correctly used to relieve unbearable suffering, does not seem to have any detrimental effect on survival of patients with terminal cancer. In this setting, palliative sedation is a medical intervention that must be considered as part of a continuum of palliative care.