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ORIGINAL ARTICLE   Free accessfree

Minerva Anestesiologica 2021 July;87(7):774-85

DOI: 10.23736/S0375-9393.21.14929-6


language: English

Update on the SedLine® algorithm for calculating the Patient State Index of older individuals during general anesthesia: a randomized controlled trial

Shinju OBARA 1 , Rieko OISHI 2, Yuko NAKANO 2, Yoshie NOJI 2, Hideaki EBANA 2, Tsuyoshi ISOSU 3, Shin KUROSAWA 2, Masahiro MURAKAWA 2

1 Department of Surgical Operation, Fukushima Medical University Hospital, Hikarigaoka, Japan; 2 Department of Anesthesiology, Fukushima Medical University School of Medicine, Hikarigaoka, Japan; 3 Department of Intensive Care, Fukushima Medical University Hospital, Hikarigaoka, Japan

BACKGROUND: The SedLine® sensor processes (Masimo Corporation; Irvine, CA, USA) raw electroencephalogram (EEG) signals and displays the depth of sedation as a Patient State Index (PSi). Reliance on standard processed EEG data and failure to recognize age-related effects can lead to an erroneous interpretation that low-amplitude EEG findings in an older patient signify an insufficient depth of anesthesia presented as abnormally high PSi values (AHPSi). We hypothesized that the incidence of AHPSi would decrease with the use of the recently-updated version of the SedLine® sensor, in which the Bispectral Index (BIS) values were used to titrate anesthesia.
METHODS: Thirty-three patients undergoing sevoflurane-remifentanil anesthesia were randomized into two groups. SedLine® sensors designed based on an old (v.1203) or updated (v.2000) algorithms were used. The BIS (v.4.1) and absolute index of total EEG power (TP) were simultaneously recorded. The attending anesthesiologists titrated the anesthetics, and BIS was maintained at 40-60. The incidence of AHPSi (PSi>50 with BIS 40-60) was calculated during the first 30 min after the start of surgery.
RESULTS: Compared to the old algorithm group, the incidence of AHPSi was significantly lower in the updated algorithm group (26.7% vs. 4.2%, P<0.001). Lower TP values and the use of the old algorithm have significant effect on increased PSi values (P<0.001).
CONCLUSIONS: The incidence of AHPSi decreased with the use of the updated version of the SedLine® algorithm.

KEY WORDS: Electroencephalography; Anesthesia; Aged

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