Using Permutation Entropy to Measure the Electroencephalographic Effects of Sevoflurane

2008 ◽  
Vol 109 (3) ◽  
pp. 448-456 ◽  
Author(s):  
Xiaoli Li ◽  
Suyuan Cui ◽  
Logan J. Voss
Keyword(s):  
Dose Response ◽  
Drug Effect ◽  
Brain Activity ◽  
Approximate Entropy ◽  
Permutation Entropy ◽  
Pharmacodynamic Modeling ◽  
Anesthetic Drug ◽  
Effect Site ◽  
Prediction Probability ◽  
Effect Site Concentration

Background Approximate entropy (AE) has been proposed as a measure of anesthetic drug effect in electroencephalographic data. Recently, a new method called permutation entropy (PE) based on symbolic dynamics was also proposed to measure the complexity in an electroencephalographic series. In this study, the AE and PE were applied to electroencephalographic recordings for revealing the effect of sevoflurane on brain activity. The dose-response relation of PE during sevoflurane anesthesia was compared with that of AE. Methods Nineteen patients' electroencephalographic data were collected during the induction of general anesthesia with sevoflurane. PE and AE were applied to the electroencephalographic recordings, and the performance of both measures was assessed by pharmacokinetic-pharmacodynamic modeling and prediction probability. To ensure an accurate complexity measure of electroencephalographic recordings, a wavelet-based preprocessor was built in advance. Results Both PE and AE could distinguish between the awake and anesthetized states and were highly correlated to each other (r = 0.8, P = 0.004). The pharmacokinetic-pharmacodynamic model adequately described the dose-response relation between PE and AE and sevoflurane effect site concentration. The coefficient R between PE and effect site concentration was 0.89 +/- 0.07 for all patients, compared with 0.60 +/- 0.14 for AE. Prediction probabilities of 0.86 +/- 0.04 and 0.79 +/- 0.09 for PE and AE showed that PE has a stronger ability to differentiate between the awake and anesthetic states. Conclusion The results show that PE can estimate the sevoflurane drug effect more effectively than AE. This method could be applied to design a new electroencephalographic monitoring system to estimate sevoflurane anesthetic drug effect.

Approximate Entropy as an Electroencephalographic Measure of Anesthetic Drug Effect during Desflurane Anesthesia

2000 ◽  
Vol 92 (3) ◽  
pp. 715-726 ◽  
Author(s):  
Jörgen Bruhn ◽  
Heiko Röpcke ◽  
Andreas Hoeft
Keyword(s):  
Bispectral Index ◽  
Drug Effect ◽  
Statistical Parameter ◽  
Approximate Entropy ◽  
Pharmacodynamic Modeling ◽  
Median Frequency ◽  
Anesthetic Drug ◽  
Spectral Edge Frequency ◽  
Spectral Edge ◽  
Prediction Probability

Background The authors hypothesized that the electroencephalogram (EEG) during higher anesthetic concentrations would show more "order" and less "randomness" than at lower anesthetic concentrations. "Approximate entropy" is a new statistical parameter derived from the Kolmogorov-Sinai entropy formula which quantifies the amount of regularity in data. The approximate entropy quantifies the predictability of subsequent amplitude values of the EEG based on the knowledge of the previous amplitude values. The authors investigated the dose-response relation of the EEG approximate entropy during desflurane anesthesia in comparison with spectral edge frequency 95, median frequency, and bispectral index. Methods Twelve female patients were studied during gynecologic laparotomies. Between opening and closure of the peritoneum, end-tidal desflurane concentrations were varied between 0.5 and 1.6 minimum alveolar concentration (MAC). The EEG approximate entropy, median EEG frequency, spectral edge frequency 95, and bispectral index were determined and the performance of each to predict the desflurane effect compartment concentration, obtained by simultaneous pharmacokinetic-pharmacodynamic modeling, was compared. Results Electroencephalogram approximate entropy decreased continuously over the observed concentration range of desflurane. The performance of the approximate entropy (prediction probability PK = 0.86 +/- 0.06) as an indicator for desflurane concentrations is similar to spectral edge frequency 95 (PK = 0.86 +/- 0.06) and bispectral index (PK = 0.82 +/- 0.06) and is statistically significantly better than median frequency (PK = 0.78 +/- 0.06). Conclusions The amount of regularity in the EEG increases with increasing desflurane concentrations. The approximate entropy could be a useful EEG measure of anesthetic drug effect.

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.

scholarly journals Induction Speed Is Not a Determinant of Propofol Pharmacodynamics

2004 ◽  
Vol 101 (5) ◽  
pp. 1112-1121 ◽  
Author(s):  
Anthony G. Doufas ◽  
Maryam Bakhshandeh ◽  
Andrew R. Bjorksten ◽  
Steven L. Shafer ◽  
Daniel I. Sessler
Keyword(s):  
Drug Effect ◽  
Peak Effect ◽  
Population Based ◽  
Pharmacodynamic Modeling ◽  
Time To Peak ◽  
Effect Site ◽  
Rate Of Increase ◽  
Effect Site Concentration ◽  
The Times ◽  
Plasma Effect

Background Evidence suggests that the rate at which intravenous anesthetics are infused may influence their plasma-effect site equilibration. The authors used five different rates of propofol administration to test the hypothesis that different sedation endpoints occur at the same effect site propofol concentration, independent of the infusion rate. The authors concurrently evaluated the automated responsiveness monitor (ARM) against other sedation measures and the propofol effect site concentration. Methods With Human Studies Committee approval, 18 healthy volunteers received five consecutive target-controlled propofol infusions. During each infusion, the effect site concentration was increased by a rate of 0.1, 0.3, 0.5, 0.7, or 0.9 microg . ml . min. The Bispectral Index and ARM were recorded at frequent intervals. The times of syringe drop and loss and recovery of responsiveness were noted. Pharmacokinetic and pharmacodynamic modeling was performed using NONMEM. Results When the correct rate of plasma-effect site equilibration was determined for each individual (plasma-effect site equilibration = 0.17 min, time to peak effect = 2.7 min), the effect site concentrations associated with each clinical measure were not affected by the rate of increase of effect site propofol concentration. ARM correlated with all clinical measures of drug effect. Subjects invariably stopped responding to ARM at lower effect site propofol concentrations than those associated with loss of responsiveness. Conclusions : Population-based pharmacokinetics, combined with real-time electroencephalographic measures of drug effect, may provide a means to individualize pharmacodynamic modeling during target-controlled drug delivery. ARM seems useful as an automated measure of sedation and may provide the basis for automated monitoring and titration of sedation for a propofol delivery system.

Spectral Entropy and Bispectral Index as Measures of the Electroencephalographic Effects of Sevoflurane

2004 ◽  
Vol 101 (6) ◽  
pp. 1275-1282 ◽  
Author(s):  
Richard Klaus Ellerkmann ◽  
Vidal-Markus Liermann ◽  
Thorsten Michael Alves ◽  
Ingobert Wenningmann ◽  
Sascha Kreuer ◽  
...  
Keyword(s):  
Bispectral Index ◽  
Drug Effects ◽  
Correlation Coefficients ◽  
Pharmacodynamic Modeling ◽  
Frequency Range ◽  
Anesthetic Drug ◽  
State Entropy ◽  
Prediction Probability ◽  
Effect Site Concentration ◽  
Response Entropy

Background Recently, entropy algorithms have been proposed as electroencephalographic measures of anesthetic drug effects. Datex-Ohmeda (Helsinki, Finland) introduced the Entropy Module, a new electroencephalographic monitor designed for measuring depth of anesthesia. The monitor calculates a state entropy (SE) computed over the frequency range of 0.8-32 Hz and a response entropy (RE) computed over the frequency range of 0.8-47 Hz. The authors investigated the dose-response relation of SE and RE during sevoflurane anesthesia in comparison with the Bispectral Index (BIS). Methods Sixteen patients were studied without surgical stimulus. Anesthesia was induced by sevoflurane inhalation with a tight-fitting facemask. Sevoflurane concentrations were increased and subsequently decreased and increased two to four times until the measurement was stopped and patients were intubated for surgery. The performances of SE, RE, and BIS to predict the estimated sevoflurane effect site concentration, obtained by simultaneous pharmacokinetic and pharmacodynamic modeling, were compared by calculating the correlation coefficients and the prediction probability. Results State entropy, RE, and BIS values decreased continuously over the observed concentration range of sevoflurane. Correlation coefficients were slightly but not significantly better for entropy parameters (0.87 +/- 0.09 and 0.86 +/- 0.10 for SE and RE, respectively) than for BIS (0.85 +/- 0.12). Calculating the prediction probability confirmed these results with a prediction probability of 0.84 +/- 0.05 and 0.82 +/- 0.06 for SE and RE, respectively, and 0.80 +/- 0.06 for BIS. Conclusion State entropy and RE seem to be useful electroencephalographic measures of sevoflurane drug effect.

Spectral Entropy as an Electroencephalographic Measure of Anesthetic Drug Effect

2004 ◽  
Vol 101 (1) ◽  
pp. 34-42 ◽  
Author(s):  
Ann L.G. Vanluchene ◽  
Hugo Vereecke ◽  
Olivier Thas ◽  
Eric P. Mortier ◽  
Steven L. Shafer ◽  
...  
Keyword(s):  
Drug Effect ◽  
Rank Correlation ◽  
Burst Suppression ◽  
Spectral Entropy ◽  
Anesthetic Drug ◽  
Mixed Effect ◽  
Nonlinear Mixed Effect ◽  
Prediction Probability ◽  
Nonlinear Mixed Effect Modeling ◽  
Mixed Effect Modeling

Background The authors compared the behavior of two calculations of electroencephalographic spectral entropy, state entropy (SE) and response entropy (RE), with the A-Line ARX Index (AAI) and the Bispectral Index (BIS) and as measures of anesthetic drug effect. They compared the measures for baseline variability, burst suppression, and prediction probability. They also developed pharmacodynamic models relating SE, RE, AAI, and BIS to the calculated propofol effect-site concentration (Ceprop). Methods With institutional review board approval, the authors studied 10 patients. All patients received 50 mg/min propofol until either burst suppression greater than 80% or mean arterial pressure less than 50 mmHg was observed. SE, RE, AAI, and BIS were continuously recorded. Ceprop was calculated from the propofol infusion profile. Baseline variability, prediction of burst suppression, prediction probability, and Spearman rank correlation were calculated for SE, RE, AAI, and BIS. The relations between Ceprop and the electroencephalographic measures of drug effect were estimated using nonlinear mixed effect modeling. Results Baseline variability was lowest when using SE and RE. Burst suppression was most accurately detected by spectral entropy. Prediction probability and individualized Spearman rank correlation were highest for BIS and lowest for SE. Nonlinear mixed effect modeling generated reasonable models relating all four measures to Ceprop. Conclusions Compared with BIS and AAI, both SE and RE seem to be useful electroencephalographic measures of anesthetic drug effect, with low baseline variability and accurate burst suppression prediction. The ability of the measures to predict Ceprop was best for BIS.

Parameter selection in permutation entropy for an electroencephalographic measure of isoflurane anesthetic drug effect

2012 ◽  
Vol 27 (2) ◽  
pp. 113-123 ◽  
Author(s):  
Duan Li ◽  
Zhenhu Liang ◽  
Yinghua Wang ◽  
Satoshi Hagihira ◽  
Jamie W. Sleigh ◽  
...  
Keyword(s):  
Drug Effect ◽  
Parameter Selection ◽  
Permutation Entropy ◽  
Anesthetic Drug

Comparison of Plasma Compartment versus  Two Methods for Effect Compartment–controlled Target-controlled Infusion for Propofol

2000 ◽  
Vol 92 (2) ◽  
pp. 399-399 ◽  
Author(s):  
Michel M. R. F. Struys ◽  
Tom De Smet ◽  
Birgit Depoorter ◽  
Linda F. M. Versichelen ◽  
Eric P. Mortier ◽  
...  
Keyword(s):  
Time Course ◽  
Drug Effect ◽  
Peak Effect ◽  
Effect Compartment ◽  
Loss Of Consciousness ◽  
Group Iii ◽  
Time To Peak ◽  
Effect Site ◽  
Effect Site Concentration ◽  
Plasma Effect

Background Target-controlled infusion (TCI) systems can control the concentration in the plasma or at the site of drug effect. A TCI system that targets the effect site should be able to accurately predict the time course of drug effect. The authors tested this by comparing the performance of three control algorithms: plasmacontrol TCI versus two algorithms for effect-site control TCI. Methods One-hundred twenty healthy women patients received propofol via TCI for 12-min at a target concentration of 5.4 microg/ml. In all three groups, the plasma concentrations were computed using pharmacokinetics previously reported. In group I, the TCI device controlled the plasma concentration. In groups II and III, the TCI device controlled the effect-site concentration. In group II, the effect site was computed using a half-life for plasma effect-site equilibration (t1/2k(eo)) of 3.5 min. In group III, plasma effect-site equilibration rate constant (k(eo)) was computed to yield a time to peak effect of 1.6 min after bolus injection, yielding a t1/2keo of 34 s. the time course of propofol was measured using the bispectral index. Blood pressure, ventilation, and time of loss of consciousness were measured. Results The time course of propofol drug effect, as measured by the bispectral index, was best predicted in group III. Targeting the effect-site concentration shortened the time to loss of consciousness compared with the targeting plasma concentration without causing hypotension. The incidence of apnea was less in group III than in group II. Conclusion Effect compartment-controlled TCI can be safely applied in clinical practice. A biophase model combining the Marsh kinetics and a time to peak effect of 1.6 min accurately predicted the time course of propofol drug effect.

scholarly journals Pharmacokinetic-Pharmacodynamic Modeling of Propofol in Children

2010 ◽  
Vol 113 (2) ◽  
pp. 343-352 ◽  
Author(s):  
Agnes Rigouzzo ◽  
Frederique Servin ◽  
Isabelle Constant
Keyword(s):  
Peak Effect ◽  
Concentration Effect ◽  
Pharmacodynamic Modeling ◽  
Maximal Effect ◽  
Time To Peak ◽  
Effect Site ◽  
Mixed Effects Modeling ◽  
Effect Site Concentration ◽  
Relationship Of ◽  
The Relationship

Background The aim of this study was to identify the best model to describe pharmacokinetics and pharmacodynamics in prepubertal children and therefore to calculate the corresponding pharmacodynamic parameters. In addition, and to confirm our method, a group of postpubertal subjects was also studied. Methods Sixteen children (9.5 yr, range 6-12) and 13 adults (22 yr, range 13-35) were included. Induction was performed by plasma target-controlled infusion of propofol (6 microg/ml) based on the Kataria model in children and on the Schnider model in adults. The relationship of bispectral index to predicted concentrations was studied during induction using the Kataria, pediatric Marsh, Schüttler, and Schnider models in children. Because the best performance was obtained, strangely enough, with the Schnider model, the two groups were pooled to investigate influence of puberty on pharmacodynamic parameters (kE0 [plasma effect-site equilibration rate constant] and Ce50 [effect-site concentration corresponding with 50% of the maximal effect]). The time-to-peak effect was calculated, and the kE0 was determined for the Kataria model (nonlinear mixed-effects modeling; pkpdtools). Results In children, the predicted concentration/effect relationship was best described using the Schnider model. When the whole population was considered, a significant improvement in this model was obtained using puberty as a covariate for kE0 and Ce50. The time to peak effect, Tpeak (median, 0.71 [range, 0.37-1.64] and 1.73 [1.4-2.68] min), and the Ce50 (3.71 [1.88-4.4] and 3.07 [2.95-5.21] microg/ml) were shorter and higher, respectively, in children than in adults. The kE0 linked to the Kataria model was 4.6 [1.4-11] min. Conclusions In children, the predicted concentration/effect relationships were best described using the Schnider model described for adults compared with classic pediatric models. The study suggests that the Schnider model might be useful for propofol target-control infusion in children.

scholarly journals Effect site concentration of propofol at induction and recovery of anaesthesia - A correlative dose-response study

2018 ◽  
Vol 62 (4) ◽  
pp. 263 ◽  
Author(s):  
Vasanth Sukumar ◽  
Arathi Radhakrishnan ◽  
VenkateshH Keshavan
Keyword(s):  
Dose Response ◽  
Effect Site ◽  
Effect Site Concentration ◽  
Dose Response Study
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