Depth of Anaesthesia Measured by Patient State Index (PSi) Does Not Correlate With Increased Seizure Duration During Electroconvulsive Therapy
(2026) In Acta Anaesthesiologica Scandinavica 70(1). p.1-7- Abstract
BACKGROUND: Seizure duration during electroconvulsive therapy (ECT) correlates with treatment efficacy and may be influenced by depth of anaesthesia. The Patient State Index (PSi), derived from processed EEG, offers a potential method to monitor depth of anaesthesia during ECT. This study examined the correlation between pre-ictal PSi and EEG-seizure duration.
METHODS: In this prospective observational study, adult patients undergoing routine ECT at a Swedish university hospital were monitored using the SedLine pEEG system. Anaesthetic care followed standard protocols and the clinical team was blinded to PSi values. Pre-ictal PSi was defined as the final value prior to the ECT stimulus. EEG-seizure duration and relevant clinical... (More)
BACKGROUND: Seizure duration during electroconvulsive therapy (ECT) correlates with treatment efficacy and may be influenced by depth of anaesthesia. The Patient State Index (PSi), derived from processed EEG, offers a potential method to monitor depth of anaesthesia during ECT. This study examined the correlation between pre-ictal PSi and EEG-seizure duration.
METHODS: In this prospective observational study, adult patients undergoing routine ECT at a Swedish university hospital were monitored using the SedLine pEEG system. Anaesthetic care followed standard protocols and the clinical team was blinded to PSi values. Pre-ictal PSi was defined as the final value prior to the ECT stimulus. EEG-seizure duration and relevant clinical variables were extracted from health records. The primary outcome was the association between pre-ictal PSi and EEG-seizure duration, analysed using a linear mixed-effects model adjusting for age and use of benzodiazepines or anticonvulsants. Secondary analyses explored sex and age effects on PSi over time and differences between baseline and pre-ictal PSi.
RESULTS: Eighty-seven ECT sessions in 37 patients were analysed. Median baseline PSi was 94 (IQR 4) and pre-ictal PSi was 38 (IQR 31; p < 0.001). No correlation was found between pre-ictal PSi and EEG-seizure duration. There were no significant effects of age or sex on pre-ictal PSi while there was a significant difference between sexes on baseline PSi. Artefact and EMG activity in the EEG signal were minimal.
CONCLUSION: Pre-ictal PSi was not associated with EEG-seizure duration.
EDITORIAL COMMENT: This study found no evidence to support a correlation between pre-ictal Patient State index and seizure duration, thereby challenging any clinical utility for guiding ECT administration.
(Less)
- author
- Jildenstål, Pether LU ; Nordenskjöld, Axel ; Edström, Måns and Otterbeck, Alexander
- organization
- publishing date
- 2026-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Humans, Electroconvulsive Therapy/methods, Female, Male, Seizures/physiopathology, Prospective Studies, Electroencephalography, Middle Aged, Aged, Anesthesia/methods, Adult, Aged, 80 and over, Time Factors
- in
- Acta Anaesthesiologica Scandinavica
- volume
- 70
- issue
- 1
- article number
- e70152
- pages
- 1 - 7
- publisher
- Blackwell Munksgaard
- external identifiers
-
- scopus:105022235075
- pmid:41254981
- ISSN
- 0001-5172
- DOI
- 10.1111/aas.70152
- language
- English
- LU publication?
- yes
- additional info
- © 2025 The Author(s). Acta Anaesthesiologica Scandinavica published by John Wiley & Sons Ltd on behalf of Acta Anaesthesiologica Scandinavica Foundation.
- id
- 9300c168-71f6-4428-80bb-42cb9e2c2b97
- date added to LUP
- 2025-12-02 14:48:50
- date last changed
- 2025-12-03 04:01:47
@article{9300c168-71f6-4428-80bb-42cb9e2c2b97,
abstract = {{<p>BACKGROUND: Seizure duration during electroconvulsive therapy (ECT) correlates with treatment efficacy and may be influenced by depth of anaesthesia. The Patient State Index (PSi), derived from processed EEG, offers a potential method to monitor depth of anaesthesia during ECT. This study examined the correlation between pre-ictal PSi and EEG-seizure duration.</p><p>METHODS: In this prospective observational study, adult patients undergoing routine ECT at a Swedish university hospital were monitored using the SedLine pEEG system. Anaesthetic care followed standard protocols and the clinical team was blinded to PSi values. Pre-ictal PSi was defined as the final value prior to the ECT stimulus. EEG-seizure duration and relevant clinical variables were extracted from health records. The primary outcome was the association between pre-ictal PSi and EEG-seizure duration, analysed using a linear mixed-effects model adjusting for age and use of benzodiazepines or anticonvulsants. Secondary analyses explored sex and age effects on PSi over time and differences between baseline and pre-ictal PSi.</p><p>RESULTS: Eighty-seven ECT sessions in 37 patients were analysed. Median baseline PSi was 94 (IQR 4) and pre-ictal PSi was 38 (IQR 31; p < 0.001). No correlation was found between pre-ictal PSi and EEG-seizure duration. There were no significant effects of age or sex on pre-ictal PSi while there was a significant difference between sexes on baseline PSi. Artefact and EMG activity in the EEG signal were minimal.</p><p>CONCLUSION: Pre-ictal PSi was not associated with EEG-seizure duration.</p><p>EDITORIAL COMMENT: This study found no evidence to support a correlation between pre-ictal Patient State index and seizure duration, thereby challenging any clinical utility for guiding ECT administration.</p>}},
author = {{Jildenstål, Pether and Nordenskjöld, Axel and Edström, Måns and Otterbeck, Alexander}},
issn = {{0001-5172}},
keywords = {{Humans; Electroconvulsive Therapy/methods; Female; Male; Seizures/physiopathology; Prospective Studies; Electroencephalography; Middle Aged; Aged; Anesthesia/methods; Adult; Aged, 80 and over; Time Factors}},
language = {{eng}},
number = {{1}},
pages = {{1--7}},
publisher = {{Blackwell Munksgaard}},
series = {{Acta Anaesthesiologica Scandinavica}},
title = {{Depth of Anaesthesia Measured by Patient State Index (PSi) Does Not Correlate With Increased Seizure Duration During Electroconvulsive Therapy}},
url = {{http://dx.doi.org/10.1111/aas.70152}},
doi = {{10.1111/aas.70152}},
volume = {{70}},
year = {{2026}},
}