How to measure the effects and potential adverse events of palliative sedation? An integrative review

María Arantzamendi, Alazne Belar Beitia and Carlos Centeno, researchers from the Instituto Cultura y Sociedad, Universidad de Navarra (Spain), are members of the Palliative Sedation consortium. Here, they explain the background to a longer article published in ‘Palliative Medicine’ and available open access.

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Left to right: Alazne Belar Beitia,  Carlos Centeno and María Arantzamendi, researchers at the Instituto Cultura y Sociedad, Universidad de Navarra, Spain, and members of the Palliative Sedation consortium.

In an earlier post on the EAPC blog, Jeroen Hasselaar, Sheila Payne and Julie Ling talked about a European-funded Horizon 2020 Research Project, Palliative Sedation, which investigates current clinical practice, reviews guidelines and includes a prospective clinical study about Palliative Sedation for patients at the end of life across Europe. ¹

Although there are some national and regional guidelines on palliative sedation and there is an EAPC framework, ² many questions remain unanswered, including how to measure the effects and potential adverse events of palliative sedation. As an essential foundation of this project the Atlantes team started by undertaking an extensive review of the literature on palliative sedation.

This review goes beyond pharmacological sedation ³  or the use of observational scales ⁴ and seeks to establish the adequacy, timing and expertise for utilization of palliative sedation. It was time for a much-needed update of the literature on current clinical practice to understand how the potential effects and possible adverse events of palliative sedation were measured through an integrative review.

It is clear that there is international interest in the topic (we included 26 articles from 14 different countries ⁵). There has also been an increase in the availability of validated monitoring instruments of refractory symptoms and the effects of palliative sedation over the last 10 years.

Instruments to assess refractory symptoms

Commonly used instruments in clinical palliative care practice are used to identify refractory symptoms. The most frequently assessed symptoms are delirium and pain. Profound psychological or existential distress is mentioned as indications but there was no information on how these assessments were conducted. When patients were unable to provide details about their symptoms (i.e, due to delirium, the depth of sedation etc), proxies were identified as an important source of information. However, in the papers included in this review we did not find assessment instruments validated for proxy use.

Instruments to assess the effects and potential adverse events of palliative sedation

To assess sedation, we noted some scales that are frequently used and adapted to the palliative care context, such as the Richmond Agitation Sedation Scale-Palliative (RASS-PAL). Additionally, some comfort scales were also used as an outcome measurement in sedated patients (the Discomfort Scale-Dementia of Alzheimer (DS-DAT) or the Patient Comfort Score (PCS)). These provide a complementary approach to the more traditionally used ones that are based on symptom and sedation level, although importantly these have not yet been validated in palliative sedation.

This review suggests that there is limited information on unintended effects of palliative sedation. Several articles demonstrated that palliative sedation does not shorten survival and that there are very few adverse events (e.g. paradoxical agitation); however, information about how these were assessed was limited.

As the project develops, the consortium members will be contributing further articles to the EAPC blog, all of which you will find in the ‘Palliative Sedation Horizon 2020′ category.

References

1. Payne SA, Hasselaar J. European Palliative Sedation Project. J Palliat Med. 2020; 23(2):154-155. doi:10.1089/jpm.2019.0606
2. Cherny NI, Radbruch L. European Association for Palliative Care (EAPC) recommended framework for the use of sedation in palliative care. Palliat Med. 2009; 23(7):581–593.
3. Beller EM, van Driel ML, McGregor L, et al. Palliative pharmacological sedation for terminally ill adults. Cochrane Database Syst Rev. 2015; 1(1):CD010206. Published 2015 Jan 2. doi:11002/14651858.CD010206.pub2.
4. Brinkkemper T, Van Norel AM, Szadek KM, et al. The use of observational scales to monitor symptom control and depth of sedation in patients requiring palliative sedation: A systematic review. Palliat Med. 2013;27(1):54–67.
5. Belar A, Arantzamendi M, Payne S, Rijpstra M, Hasselaar J, Radbruch L, Vanderelst M, Ling J, Centeno C. How to measure the effects and potential adverse events of palliative sedation? An integrative review. Palliat Med. First published online 14 December 2020. Download the article in open access here:  https://journals.sagepub.com/doi/full/10.1177/0269216320974264

Links

• Follow us on Twitter: @PallSed, @AtlantesPC 
• Facebook: @AtlantesPC
• Palliative Sedation website.
• ATLANTES WP1 leading institution website.
• Read more posts about Palliative Sedation Horizon 2020.
• Read more posts about Palliative Sedation generally here.

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