Introduction
In case of untreatable suffering at the end of life, continuous sedation until death (CSD) may be the only treatment option left. Because these patients cannot communicate anymore, caregivers have to rely on behavioral observation to assess the patient’s comfort. Recently, however, a number of studies from the neurosciences have shown that sometimes consciousness and pain are undetectable with these traditional behavioral methods. The aim of this study was to find out if subjective caregiver assessments of consciousness and pain would be confirmed by objective neurophysiological measures.

Methods
In this prospective observational study, we observed patients from the start of palliative sedation until death. Subjective caregiver assessments of level of consciousness and pain based on behavioral observations were compared with objective measures from neurophysiological monitoring devices.

Results
We collected and analyzed 108 subjective caregiver assessments in a sample of 12 patients and 32 assessments by traditionally used observational scales. We compared these with objective neurophysiological measures. Sensitivity and specificity of caregivers’ subjective assessments of consciousness was 23.6 and 91.1% respectively, with an accuracy of 54.0% and interrater reliability (κ) of 0.13. For pain, this was 0 and 94.79%, respectively, an accuracy of 88%, and an inter-rater reliability (κ) of − 0.063. Agreement between caregivers’ subjective assessments and objective neurophysiological measures of consciousness and pain was very poor.

Conclusions
Caregivers’ subjective assessment of level of consciousness and pain during CSD is unreliable compared with objective neurophysiological monitoring. Our results suggest that assessments of patient comfort during CSD could have been improved substantially by including objective monitoring of level of consciousness and pain.

Trial Registration
The protocol for this observational study has been registered retrospectively at Clinical-Trials.gov (ID NCT03273244).
Original languageEnglish
JournalPain and Therapy
DOIs
Publication statusE-pub ahead of print - 5 Nov 2020

ID: 54365302