Current Status of EEG-Based Depth-of-Consciousness Monitoring During General Anesthesia

Musialowicz, Tadeusz; Lahtinen, Pasi

doi:10.1007/s40140-014-0061-x

Cited by 27 publications

(26 citation statements)

References 71 publications

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“…It was previously thought that unconsciousness and amnesia during general anesthesia were brain cortical phenomena [4]. However, according to the study of Långsjö et al [33], subcortical structures of the brain are also involved during the emergence of consciousness during anesthesia.…”

Section: Discussionmentioning

confidence: 97%

“…SE parameter of spectral entropy is delivered from frontal EEG and this may be the reason why no changes in the SE value were seen during arousal i.e., this parameter does not monitor activity in subcortical brain structures. This can be considered as a limitation of EEG based anesthesia monitoring since it only registers the cortical frontal EEG [4]. However, frontal muscles activation, measured by RE parameter, may indicate inadequate subcortical component of anesthesia.…”

Section: Discussionmentioning

confidence: 99%

“…Thus, the EEG-based depth-of-anesthesia (DoA) monitors utilize a processed EEG signal and then translate it into simple numerical indices corresponding to the patient's level of consciousness during general anesthesia [3,4]. The Bispectral Index (BIS) was the first commercially available technique for monitoring the hypnotic level during anesthesia, exploiting a processed EEG-based BIS algorithm [5].…”

Section: Introductionmentioning

confidence: 99%

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Spectral Entropy Parameters during Rapid Ventricular Pacing for Transcatheter Aortic Valve Implantation

Musialowicz

Valtola

Hippeläinen

et al. 2017

Entropy

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Abstract:The time-frequency balanced spectral entropy of the EEG is a monitoring technique measuring the level of hypnosis during general anesthesia. Two components of spectral entropy are calculated: state entropy (SE) and response entropy (RE). Transcatheter aortic valve implantation (TAVI) is a less invasive treatment for patients suffering from symptomatic aortic stenosis with contraindications for open heart surgery. The goal of hemodynamic management during the procedure is to achieve hemodynamic stability with exact blood pressure control and use of rapid ventricular pacing (RVP) that result in severe hypotension. The objective of this study was to examine how the spectral entropy values respond to RVP and other critical events during the TAVI procedure. Twenty one patients undergoing general anesthesia for TAVI were evaluated. The RVP was used twice during the procedure at a rate of 185 ± 9/min with durations of 16 ± 4 s (range 8-22 s) and 24 ± 6 s (range 18-39 s). The systolic blood pressure during RVP was under 50 ± 5 mmHg. Spectral entropy values SE were significantly declined during the RVP procedure, from 28 ± 13 to 23 ± 13 (p < 0.003) and from 29 ± 12 to 24 ± 10 (p < 0.001). The corresponding values for RE were 29 ± 13 vs. 24 ± 13 (p < 0.006) and 30 ± 12 vs. 25 ± 10 (p < 0.001). Both SE and RE values returned to the pre-RVP values after 1 min. Ultra-short hypotension during RVP changed the spectral entropy parameters, however these indices reverted rapidly to the same value before application of RVP.

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Section: Discussionmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Spectral Entropy Parameters during Rapid Ventricular Pacing for Transcatheter Aortic Valve Implantation

Musialowicz

Valtola

Hippeläinen

et al. 2017

Entropy

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“…When BIS is over 60, there is the possibility of awareness risk during general anesthesia. BIS monitoring has been reported to reduce the risk of intraoperative awareness in populations at high risk 6,7 . A previous study reported that for patients receiving 4 mg/ kg of thiopental, the BIS value is >60 at the time of incision 8 .…”

Section: Comparison Of Electroencephalogram Between Propofol-and Thiomentioning

confidence: 99%

Comparison of electroencephalogram between propofol- and thiopental-induced anesthesia for awareness risk in pregnant women

Park

Kim

et al. 2020

Sci Rep

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Some studies have suggested that EEG oscillations are related to altered states of consciousness produced by anesthetics 11-15. However, there is a lack of detailed characterization of oscillatory EEG activity regarding thiopental and propofol administration in pregnant women. Therefore, characterizing EEG spectral dynamics should help to establish the risk of awareness during general anesthesia. We aimed to investigate whether there are any differences in frontal brain oscillations between propofol-and thiopental-induced general anesthesia for cesarean section. Further, BIS and entropy analyses were also conducted to evaluate awareness risk in each group. Methods patient population. This study was approved by the Asan Medical Centre institutional review board (IRB number 2019-0737). The need for informed consent was waived, considering the retrospective nature of this analysis. The study conformed to the tenets of the Declaration of Helsinki. A retrospective analysis of EEG data recorded during elective cesarean section was conducted between September 2017 and May 2019. Our institute has traditionally used only thiopental (Pentothal sodium, JW Pharmaceutical, Seoul, Korea) for cesarean section, but there was a temporary supply interruption from November 2017 until March 2018. Propofol was then used as an alternative induction agent for cesarean section. After the re-supply of thiopental, agent selection was decided by the attending anesthesiologist. We identified all parturient women who received general anesthesia. Through chart review, parturients were divided into two groups according to the anesthetic agent: the thiopental and propofol groups. Inclusion criteria were between 20 and 44 years old, American Society of Anesthesiologist grade 1 or 2, and elective operation. Patients with the following conditions were excluded from the study: (1) cases where regional anesthesia was converted to general anesthesia; (2) exposure to sevoflurane before the induction of general anesthesia; (3) missing Vital Recorder data; (4) difficult airway management cases. Anesthetic management. Our institutional standardized anesthesia protocols were used for cesarean section. All parturient women received at least 3 min of pre-oxygenation using 100% oxygen, followed by RSI with cricoid pressure. Thiopental 5 mg/kg or propofol 2 mg/kg was administered, followed by succinylcholine 1.5 mg/kg to facilitate intubation. After disappearance of fasciculation and of the electromyography (EMG) activity bar on the BIS monitor, all patients were intubated with a 6.5-cuffed tracheal tube using a video-scope. After confirming successful intubation, rocuronium 0.5 mg/kg was immediately administered to achieve further muscle relaxation. Anesthesia was maintained with 50% nitrous oxide (N 2 O) in oxygen (6 L/min) and sevoflurane. The initially inspired concentration of sevoflurane was set at 2.0 vol% on the vaporizer until the end-tidal sevoflurane (Et-Sevo) reached 1.3 vol%. A skin incision was made after the anesthesiologist confirmed intubatio...

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“…All patients were ventilated with 100% oxygen for a few minutes before and after RVP periods. Anesthesia was maintained with an infusion (2 -8 mg/kg/h) of propofol aiming at a state entropy of under 60 [19].…”

Section: Anesthesia and Hemodynamic Managementmentioning

confidence: 99%

Mixed Venous Oxygen Saturation during the Transcatheter Aortic Valve Replacement—A Prospective Cohort Study

Musialowicz¹,

Ellam²,

Valtola³

et al. 2019

OJAnes

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Purpose: Patients scheduled to undergo the transcatheter aortic valve replacement (TAVR) are usually octogenarians with severe co-morbidities and an increased risk of surgery-associated complications. The aim of this study was to determine the incidence of insufficient oxygen delivery as measured by mixed venous oxygen saturation (SvO 2 ) via invasive continuous cardiopulmonary monitoring and the low cardiac output syndrome (LCOS) in patients undergoing the TAVR procedure. The second objective was to examine how these hemodynamic measurements would change during critical events, such as rapid ventricular pacing (RVP) during this procedure. Methods: This prospective, observational study, examined twenty patients undergoing TAVR under general anesthesia. Hemodynamic variables, SvO 2 and the continuous cardiac output (CO) were assessed using pulmonary artery catheter (PAC) and a Vigilance ® monitor. Insufficient oxygen delivery was defined as a SvO 2 value under 58% and LCOS as a cardiac index (CI) under 2 L/min/m 2 . Total intravenous anesthesia and hemodynamic management protocol were standardized. RVP was induced twice during the procedure at a frequency of 180 -200/min. Predefined clinical endpoints were assessed during the procedure and hemodynamic values were analyzed before and after twelve critical events. Results: The data of twenty patients with a mean age of 80 ± 4 years and EuroSCORE 18 ± 10 were analyzed. Fourteen (70%) of the TAVR procedures were performed transapically, the other six (30%) transfemorally. The SvO 2 value under 58% (mean 54 ± 6) and the CI under 2 L/min/m 2 (mean 1.6 ± 0.2) were detected in 60% of patients (n = 12) before the use of RVP. All of these patients received perioperative inotropic medication and required norepinephrine infusion for maintenance of adequate blood pressure. The SvO 2 , CO and CI were significantly decreased after the use of RVP (P < 0.001 and P < 0.03). The SvO 2 reverted rapidly to the same level as before the application How to cite this paper: Musialowicz, T., Ellam, S., Valtola, A., Halonen, J. and Lahtinen, P. (2019) Mixed Venous Oxygen Saturation during the Transcatheter Aortic Valve Replacement-A Prospective Cohort Study. Open Journal of Anesthesiology,9,[140][141][142][143][144][145][146][147][148][149][150][151][152][153] of RVP (1 min), CO, and CI 10 min later. At the end of the operation SvO 2 values were at same level as before RVP and CO and CI were higher than before RVP. Conclusion: A high incidence of insufficient oxygen delivery and low cardiac output syndrome were detected in patients undergoing TAVR procedures. Nonetheless, all hemodynamic values returned rather rapidly to the same level as before the use of the RVP and were at the optimal level at the end of the procedure. According to the current study, the most hemodynamically hazardous steps during TAVR are the use of RVP sequences, the induction of anesthesia and the initiation of surgery.

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Current Status of EEG-Based Depth-of-Consciousness Monitoring During General Anesthesia

Cited by 27 publications

References 71 publications

Spectral Entropy Parameters during Rapid Ventricular Pacing for Transcatheter Aortic Valve Implantation

Spectral Entropy Parameters during Rapid Ventricular Pacing for Transcatheter Aortic Valve Implantation

Comparison of electroencephalogram between propofol- and thiopental-induced anesthesia for awareness risk in pregnant women

Mixed Venous Oxygen Saturation during the Transcatheter Aortic Valve Replacement—A Prospective Cohort Study

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