Lower alpha frequency of intraoperative frontal EEG is associated with postoperative delirium : A secondary propensity-matched analysis

Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved..

BACKGROUND: Postoperative delirium (POD) is a serious complication of surgery, especially in the elderly patient population. It has been proposed that decreasing the amount of anesthetics by titrating to an EEG index will lower POD rate, but clear evidence is missing. A strong age-dependent negative correlation has been reported between the peak oscillatory frequency of alpha waves and end-tidal anesthetic concentration, with older patients generating slower alpha frequencies. We hypothesized, that slower alpha oscillations are associated with a higher rate of POD.

METHOD: Retrospective analysis of patients` data from a prospective observational study in cardiac surgical patients approved by the Bernese Ethics committee. Frontal EEG was recorded during Isoflurane effect-site concentrations of 0.7 to 0.8 and peak alpha frequency was measured at highest power between 6 and 17 Hz. Delirium was assessed by chart review. Demographic and clinical characteristics were compared between POD and non-POD groups. Selection bias was addressed using nearest neighbor propensity score matching (PSM) for best balance. This incorporated 18 variables, whereas patients with missing variable information or without an alpha oscillation were excluded.

RESULT: Of the 1072 patients in the original study, 828 were included, 73 with POD, 755 without. PSM allowed 328 patients into the final analysis, 67 with, 261 without POD. Before PSM, 8 variables were significantly different between POD and non-POD groups, none thereafter. Mean peak alpha frequency was significantly lower in the POD in contrast to non-POD group before and after matching (7.9 vs 8.9 Hz, 7.9 vs 8.8 Hz respectively, SD 1.3, p < 0.001).

CONCLUSION: Intraoperative slower frontal peak alpha frequency is independently associated with POD after cardiac surgery and may be a simple intraoperative neurophysiological marker of a vulnerable brain for POD. Further studies are needed to investigate if there is a causal link between alpha frequency and POD.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:93

Enthalten in:

Journal of clinical anesthesia - 93(2024) vom: 01. März, Seite 111343

Sprache:

Englisch

Beteiligte Personen:

Hight, Darren [VerfasserIn]
Ehrhardt, Alexander [VerfasserIn]
Lersch, Friedrich [VerfasserIn]
Luedi, Markus M [VerfasserIn]
Stüber, Frank [VerfasserIn]
Kaiser, Heiko A [VerfasserIn]

Links:

Volltext

Themen:

Alpha rhythm
Anesthesia, general
Delirium, postoperative
Electroencephalography
Journal Article
Monitoring, intraoperative
Observational Study
Research Support, Non-U.S. Gov't
Retrospective study

Anmerkungen:

Date Completed 15.01.2024

Date Revised 12.03.2024

published: Print-Electronic

ClinicalTrials.gov: NCT02976584

Citation Status MEDLINE

doi:

10.1016/j.jclinane.2023.111343

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM364868686