Monitoring nociception and awareness during palliative sedation: A systematic review

Palliat Med. 2021 Sep;35(8):1407-1420. doi: 10.1177/02692163211022943. Epub 2021 Jun 10.


Background: Providing unawareness and pain relief are core elements of palliative sedation. In addition to clinical scales, nociception and electroencephalogram-based depth of sedation monitoring are used to assess the level of consciousness and analgesia during sedation in intensive care units and during procedures.

Aim: To determine whether reported devices impact the outcomes of palliative sedation.

Design: Systematic review and narrative synthesis of research published between January 2000 and December 2020.

Data sources: Embase, Google Scholar, PubMed, CENTRAL, and the Cochrane Library. All reports describing the use of any monitoring device to assess the level of consciousness or analgesia during palliative sedation were screened for inclusion. Data concerning safety and efficacy were extracted. Patient comfort was the primary outcome of interest. Articles reporting sedation but that did not meet guidelines of the European Association for Palliative Care were excluded.

Results: Six reports of five studies were identified. Four of these were case series and two were case reports. Together, these six reports involved a total of 67 sedated adults. Methodological quality was assessed fair to good. Medication regimens were adjusted to bispectral index monitoring values in two studies, which found poor correlation between monitoring values and observational scores. In another study, high nociception index values, representing absence of pain, were used to detect opioid overdosing. Relatives and caregivers found the procedures feasible and acceptable.

Keywords: Bispectral index monitor; analgesia; consciousness; consciousness monitor; deep sedation; nociception; palliative care; systematic review.

Publication types

  • Systematic Review

MeSH terms

  • Adult
  • Analgesia*
  • Anesthesia*
  • Conscious Sedation
  • Humans
  • Hypnotics and Sedatives
  • Nociception
  • Palliative Care


  • Hypnotics and Sedatives