Correlation of Narcotrend Index, entropy measures, and spectral parameters with calculated propofol effect-site concentrations during induction of propofol–remifentanil anaesthesia

Abstract

In all groups Narcotrend Index showed the highest correlation with the propofol effect-site concentration and the lowest variability of individual correlation values. Furthermore, only the Narcotrend Index showed a monophasic behaviour over the entire time period analysed. In the group of entropy parameters approximate entropy yielded the best results. Among the spectral parameters the burst-compensated 95% spectral edge frequency had the highest correlation with the propofol effect-site concentration. It was markedly higher than for the standard spectral edge frequency. The correlations of median frequency and amplitude entropy with propofol effect-site concentration were the lowest. CONCLUSIONS. Changes in the propofol effect-site concentration during induction of anaesthesia were best described by the multivariate Narcotrend Index compared to conventional spectral EEG parameters and different entropy measures.

Extraction of spectral based measures from MEG background oscillations in Alzheimer's disease

“…Although SEF95 has been successfully employed to monitor depth of anaesthesia [38][39][40], our results are less significant than those obtained with MF, IAF, TF and SE. This finding seems to indicate that there is little change in the spectral content at high frequencies when comparing AD patients and control subjects.…”

“…Thus, an estimation of the spectral content of PSD, called 95% spectral edge frequency, has been studied to monitor depth of anaesthesia [38,39]. Similarly, parameters from the context of nonlinear dynamics have also been employed to yield additional information to linear spectral based measures.…”

“…Similarly, parameters from the context of nonlinear dynamics have also been employed to yield additional information to linear spectral based measures. One of them is the spectral entropy, which represents the Shannon entropy computed over the normalized power spectral density function [38][39][40].…”

Complexity analysis of the biomedical signal using fuzzy entropy measurement

“…Given N points and tolerance r, ApEn(m,r,N) is approximately equal to the negative average natural logarithm of the conditional probability that two sequences that are similar for m points within the tolerance remain similar at the next point. As a statistic superior to most complexity measures [9,23,31], ApEn has been shown to have potential application to a wide range of biomedical signals such as hormone pulsatility, genetic sequences, respiratory patterns, heart rate variability, electrocardiograms, and electroencephalography. Nevertheless, ApEn always suggests more similarity than is present due to the counting of self-matches and is therefore biased.…”

Messung der Narkosetiefe

“…Für ansteigende Propofolkonzentrationen konnten im Vergleich zu klassischen EEG-Parametern für den Narcotrend die höchsten Korrelationskoeffizienten gefunden werden [31,74]. P K -Werte zwischen 0,88 und 0,91 [7,46] sind in der Literatur beschrieben.…”