Abstract
INTRODUCTION: Processed electroencephalography (pEEG) monitoring is commonly employed to assess the level of hypnosis under anaesthesia, although it is susceptible to various non-brain-related artefacts. Several sources of artefacts have been published, but how these sources affect the pEEG and their related hypnotic indices have not been summarised before. This scoping review will summarise the published literature on how non-pharmacological artefacts affect pEEG monitoring during anaesthesia andintensive care, including their influence on the hypnotic index and the underlying mechanisms of interference. METHODS AND ANALYSIS: Non-pharmacological, non-brain-related sources of artefacts affecting human patients under anaesthesia or intensive care will be included. The covered concepts include the sources of interference affecting pEEG in which the artefact causes the hypnotic index to no longer be reflective of the depth of hypnosis, how they affect the hypnotic index, and the suspected mechanism by which they affect the pEEG monitor. Databases to be searched will include PubMed, Ovid MEDLINE, Embase, Cochrane Library, CINAHL and the Web of Science. Grey literature will include sources from Google Scholar, the Web of Science, preprint repositories and reference lists of included studies and review papers. The search will be conducted on 19 June 2025, followed by a later repeat search for new articles once the data from the initial search have been extracted. The search will be limited to English articles. Search results will be imported into Covidence for screening. Data extraction will be conducted by two extractors independently, and the data will be summarised in tables. ETHICS AND DISSEMINATION: There are no ethical or safety concerns associated with this study. Ethics approval was not obtained as this scoping review will summarise data from previously published sources, and the findings will be published in a peer-reviewed journal.