New Composite Index Based on Midlatency Auditory Evoked Potential and Electroencephalographic Parameters to Optimize Correlation with Propofol Effect Site Concentration

2005 ◽  
Vol 103 (3) ◽  
pp. 500-507 ◽  
Author(s):  
Hugo E. M. Vereecke ◽  
Pablo Martinez Vasquez ◽  
Erik Weber Jensen ◽  
Olivier Thas ◽  
Rudy Vandenbroecke ◽  
...  
Keyword(s):  
Bispectral Index ◽  
Auditory Evoked Potentials ◽  
Evoked Potential ◽  
Drug Effect ◽  
Composite Index ◽  
Auditory Evoked Potential ◽  
Anesthetic Drug ◽  
Potential Index ◽  
Prediction Probability ◽  
Effect Site Concentration

Background This study investigates the accuracy of a composite index, the A-Line(R) auditory evoked potentials index version 1.6 (AAI1.6; Danmeter A/S, Odense, Denmark), as a measure of cerebral anesthetic drug effect in a model for predicting a calculated effect site concentration of propofol (CePROP). The AAI1.6 algorithm extracts information from the midlatency auditory evoked potentials, the spontaneous electroencephalographic activity, and the detection of burst suppression. The former version of this monitor, the A-Line auditory evoked potential index version 1.5, is only based on fast extracted midlatency auditory evoked potential information. Methods After institutional ethics committee approval (University Hospital, Ghent, Belgium), informed consent was obtained from 13 patients (10 women, 3 men) with an American Society of Anesthesiologists physical status of I, aged 18-65 yr, who were scheduled to undergo ambulatory gynecologic or urologic surgery. The authors evaluated for Bispectral Index, A-Line auditory evoked potential index, version 1.5, AAI1.6 scaled from 0 to 100 and AAI1.6 scaled from 0 to 60, the interpatient stability at baseline, the detection of burst suppression, prediction probability, and correlation with CePROP, during a constant infusion of 1% propofol at 300 ml/h. The authors developed pharmacodynamic models relating the predicted CePROP to each measure of cerebral anesthetic drug effect. Results Bispectral Index had the lowest interindividual baseline variability. No significant difference was found with prediction probability analysis for all measures. Comparisons for correlation were performed for all indices. The AAI1.6 scaled to 60 had a significantly higher correlation with CePROP compared with all other measures. The AAI1.6 scaled to 100 had a significant higher correlation with CePROP compared with the A-Line auditory evoked potential index version 1.5 (P < 0.05) Conclusions The authors found that the application of AAI1.6 has a better correlation with a calculated CePROP compared with a solitary fast extracting midlatency auditory evoked potential measure. Whether this improvement in pharmacodynamic tracing is accompanied by an improved clinical performance should be investigated using clinical endpoints.

Performance of the ARX-derived Auditory Evoked Potential Index as an Indicator of Anesthetic Depth

2002 ◽  
Vol 96 (4) ◽  
pp. 803-816 ◽  
Author(s):  
Michel M. R. F. Struys ◽  
Erik Weber Jensen ◽  
Warren Smith ◽  
N. Ty Smith ◽  
Ira Rampil ◽  
...  
Keyword(s):  
Bispectral Index ◽  
Evoked Potential ◽  
Auditory Evoked Potential ◽  
Noxious Stimulus ◽  
Gynecologic Surgery ◽  
Effect Compartment ◽  
Loss Of Consciousness ◽  
Anesthetic Depth ◽  
Effect Site ◽  
Effect Site Concentration

Background Autoregressive modeling with exogenous input of middle-latency auditory evoked potential (A-Line autoregressive index [AAI]) has been proposed for monitoring anesthetic depth. The aim of the current study was to compare the accuracy of this new index with the Bispectral Index (BIS), predicted effect-site concentration of propofol, and hemodynamic measures. Methods Twenty female patients scheduled for ambulatory gynecologic surgery received effect compartment controlled infusion of propofol. Target effect-site concentration was started at 1.5 microg/ml and increased every 4 min by 0.5 microg/ml. At every step, sedation level was compared with monitoring values using different clinical scoring systems and reaction to noxious stimulus. Results Bispectral Index, AAI, and predicted propofol effect-site concentration were accurate indicators for the level of sedation and loss of consciousness. Hemodynamic variables were poor indicators of the hypnotic-anesthetic status of the patient. BIS correlated best with propofol effect-site concentration, followed by AAI. Hemodynamic measurements did not correlate well. No indicators predicted reaction to noxious stimulus. Poststimulus, BIS and AAI showed an increase as a result of arousal. This reaction occurred more rapidly with the AAI than with BIS. Conclusion Bispectral Index, AAI, and predicted propofol effect-site concentration revealed information on the level of sedation and loss of consciousness but did not predict response to noxious stimulus.

Comparison of Changes in Bispectral Index and Auditory Evoked Potential Index during Endotracheal Intubation

2003 ◽  
Vol 45 (2) ◽  
pp. 184
Author(s):  
Yoon Sook Lee ◽  
Sang Soo Kang ◽  
Kyu Ho Lee ◽  
Young Mi Kim ◽  
Keun Man Shin ◽  
...  
Keyword(s):  
Endotracheal Intubation ◽  
Bispectral Index ◽  
Evoked Potential ◽  
Auditory Evoked Potential ◽  
Potential Index

Variability Comparison of the Composite Auditory Evoked Potential Index and the Bispectral Index During Propofol-Fentanyl Anesthesia

2008 ◽  
Vol 107 (1) ◽  
pp. 117-124 ◽  
Author(s):  
Benno Rehberg ◽  
Christiane Ryll ◽  
Daniel Hadzidiakos ◽  
Falk v. Dincklage ◽  
Jan H. Baars
Keyword(s):  
Bispectral Index ◽  
Evoked Potential ◽  
Auditory Evoked Potential ◽  
Potential Index

Detection of Consciousness by Electroencephalogram and Auditory Evoked Potentials

2005 ◽  
Vol 103 (5) ◽  
pp. 934-943 ◽  
Author(s):  
Gerhard Schneider ◽  
Regina Hollweck ◽  
Michael Ningler ◽  
Gudrun Stockmanns ◽  
Eberhard F. Kochs
Keyword(s):  
Model Prediction ◽  
Bispectral Index ◽  
Minimal Model ◽  
Auditory Evoked Potentials ◽  
Amplitude Spectrum ◽  
Auditory Evoked Potential ◽  
Loss Of Consciousness ◽  
Median Frequency ◽  
Data Set ◽  
Prediction Probability

Background A set of electroencephalographic and auditory evoked potential (AEP) parameters should be identified that allows separation of consciousness from unconsciousness (reflected by responsiveness/unresponsiveness to command). Methods Forty unpremedicated patients received anesthesia with remifentanil and either sevoflurane or propofol. With remifentanil infusion (0.2 microg . kg . min), patients were asked every 30 s to squeeze the investigator's hand. Sevoflurane or propofol was given until loss of consciousness. After intubation, propofol or sevoflurane was stopped until patients followed the command (return of consciousness). Thereafter, propofol or sevoflurane was started again (loss of consciousness), and surgery was performed. Return of consciousness was observed after surgery. The electroencephalogram and AEP from immediately before and after the transitions were selected. Logistic regression was calculated to identify models for the separation between consciousness and unconsciousness. For the top 10 models, 1,000-fold cross-validation was performed. Backward variable selection was applied to identify a minimal model. Prediction probability was calculated. The digitized electroencephalogram was replayed, and the Bispectral Index was measured and accordingly analyzed. Results The best full model (prediction probability 0.89) contained 15 AEP and 4 electroencephalographic parameters. The best minimal model (prediction probability 0.87) contained 2 AEP and 2 electroencephalographic parameters (median frequency of the amplitude spectrum from 8-30 Hz and approximate entropy). The prediction probability of the Bispectral Index was 0.737. Conclusions A combination of electroencephalographic and AEP parameters can be used to differentiate between consciousness and unconsciousness even in a very challenging data set. The minimal model contains a combination of AEP and electroencephalographic parameters and has a higher prediction probability than Bispectral Index for the separation between consciousness and unconsciousness.

ARX-Derived Auditory Evoked Potential Index and Bispectral Index During the Induction of Anesthesia with Propofol and Remifentanil

2003 ◽  
pp. 139-144 ◽  
Author(s):  
Gunter N. Schmidt ◽  
Petra Bischoff ◽  
Thomas Standl ◽  
Malte Issleib ◽  
Moritz Voigt ◽  
...  
Keyword(s):  
Bispectral Index ◽  
Evoked Potential ◽  
Auditory Evoked Potential ◽  
Potential Index
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