scholarly journals Effect of depth of anesthesia on the phase lag entropy in patients undergoing general anesthesia by propofol

Medicine ◽  
2020 ◽  
Vol 99 (30) ◽  
pp. e21303
Author(s):  
Jae Hong Park ◽  
Sang Eun Lee ◽  
Eunsu Kang ◽  
Yei Heum Park ◽  
Hyun-seong Lee ◽  
...  
Keyword(s):  
General Anesthesia ◽  
Phase Lag ◽  
Depth Of Anesthesia

scholarly journals Dynamic Cortical Connectivity during General Anesthesia in Surgical Patients

2019 ◽  
Vol 130 (6) ◽  
pp. 885-897 ◽  
Author(s):  
Phillip E. Vlisides ◽  
Duan Li ◽  
Mackenzie Zierau ◽  
Andrew P. Lapointe ◽  
Ka I. Ip ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
General Anesthesia ◽  
Temporal Dynamics ◽  
Transition Probabilities ◽  
Surgical Patients ◽  
Phase Lag ◽  
Cortical Connectivity ◽  
Single Measure ◽  
Connectivity Patterns ◽  
Weighted Phase Lag Index

Abstract Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background Functional connectivity across the cortex has been posited to be important for consciousness and anesthesia, but functional connectivity patterns during the course of surgery and general anesthesia are unknown. The authors tested the hypothesis that disrupted cortical connectivity patterns would correlate with surgical anesthesia. Methods Surgical patients (n = 53) were recruited for study participation. Whole-scalp (16-channel) wireless electroencephalographic data were prospectively collected throughout the perioperative period. Functional connectivity was assessed using weighted phase lag index. During anesthetic maintenance, the temporal dynamics of connectivity states were characterized via Markov chain analysis, and state transition probabilities were quantified. Results Compared to baseline (weighted phase lag index, 0.163, ± 0.091), alpha frontal–parietal connectivity was not significantly different across the remaining anesthetic and perioperative epochs, ranging from 0.100 (± 0.041) to 0.218 (± 0.136) (P > 0.05 for all time periods). In contrast, there were significant increases in alpha prefrontal–frontal connectivity (peak = 0.201 [0.154, 0.248]; P < 0.001), theta prefrontal–frontal connectivity (peak = 0.137 [0.091, 0.182]; P < 0.001), and theta frontal–parietal connectivity (peak = 0.128 [0.084, 0.173]; P < 0.001) during anesthetic maintenance. Additionally, shifts occurred between states of high prefrontal–frontal connectivity (alpha, beta) with suppressed frontal–parietal connectivity, and high frontal–parietal connectivity (alpha, theta) with reduced prefrontal–frontal connectivity. These shifts occurred in a nonrandom manner (P < 0.05 compared to random transitions), suggesting structured transitions of connectivity during general anesthesia. Conclusions Functional connectivity patterns dynamically shift during surgery and general anesthesia but do so in a structured way. Thus, a single measure of functional connectivity will likely not be a reliable correlate of surgical anesthesia.

Dynamic Cortical Connectivity during General Anesthesia in Healthy Volunteers

2019 ◽  
Vol 130 (6) ◽  
pp. 870-884 ◽  
Author(s):  
Duan Li ◽  
Phillip E. Vlisides ◽  
Max B. Kelz ◽  
Michael S. Avidan ◽  
George A. Mashour ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
General Anesthesia ◽  
Healthy Volunteers ◽  
Transition Probabilities ◽  
Burst Suppression ◽  
Occurrence Rate ◽  
Connectivity Pattern ◽  
Phase Lag ◽  
Cortical Connectivity ◽  
Isoflurane Anesthesia

Abstract Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background Recent studies of anesthetic-induced unconsciousness in healthy volunteers have focused on functional brain connectivity patterns, but the protocols rarely parallel the depth and duration of surgical anesthesia. Furthermore, it is unknown whether there is a single functional connectivity pattern that correlates with general anesthesia for the duration of prolonged anesthetic exposure. Methods The authors analyzed electroencephalographic data in 30 healthy participants who underwent induction of anesthesia with propofol followed by 3 h of isoflurane anesthesia at age-adjusted 1.3 minimum alveolar concentration. Functional connectivity was assessed by frequency-resolved weighted phase lag index between frontal and parietal channels and between prefrontal and frontal channels, which were classified into a discrete set of states through k-means cluster analysis. Temporal dynamics were evaluated by the occurrence rate and dwell time distribution for each state as well as the transition probabilities between states. Results Burst suppression was present, with mean suppression ratio reducing from 44.8 ± 32.3% to 14.0 ± 20.2% (mean ± SD) during isoflurane anesthesia (P < 0.001). Aside from burst suppression, eight connectivity states were classified by optimizing the reproducibility of clustering solutions, with each characterized by distinct properties. The temporal progression of dominant states revealed a successive shifting trajectory from the state associated with alpha frontal-parietal connectivity to those associated with delta and alpha prefrontal-frontal connectivity during induction, which was reversed during emergence. Cortical connectivity was dynamic during maintenance period, and it was more probable to remain in the same state (82.0 ± 8.3%) than to switch to a different state (P < 0.001). However, transitions to other states were structured, i.e., occurred more frequently than expected by chance. Conclusions Anesthesia-induced alterations of functional connectivity are dynamic despite the stable and prolonged administration of isoflurane, in the absence of any noxious stimuli. Changes in connectivity over time will likely yield more information as a marker or mechanism of surgical anesthesia than any single pattern.

scholarly journals Assessment of changes in the electrical activity of the brain during general anesthesia using portable electroencephalography

2020 ◽  
Vol 49 (2) ◽  
Author(s):  
Verónica Gaviria García ◽  
Daniel Loaiza López ◽  
Carolina Serna Rojas ◽  
Sara Ríos Arismendy ◽  
Eduardo Montoya Guevara ◽  
...  
Keyword(s):  
Electrical Activity ◽  
General Anesthesia ◽  
Brain Activity ◽  
Low Cost ◽  
Conscious State ◽  
Depth Of Anesthesia ◽  
Cross Sectional ◽  
Eyes Closed ◽  
Eeg Recordings ◽  
The Brain

Introduction: The analysis of the electrical activity of the brain using scalp electrodes with electroencephalography (EEG) could reveal the depth of anesthesia of a patient during surgery. However, conventional EEG equipment, due to its price and size, are not a practical option for the operating room and the commercial units used in surgery do not provide access to the electrical activity. The availability of low-cost portable technologies could provide for further research on the brain activity under general anesthesia and facilitate our quest for new markers of depth of anesthesia. Objective: To assess the capabilities of a portable EEG technology to capture brain rhythms associated with the state of consciousness and the general anesthesia status of surgical patients anesthetized with propofol. Methods: Observational, cross-sectional trial that reviewed 10 EEG recordings captured using OpenBCI portable low-cost technology, in female patients undergoing general anesthesia with propofol. The signal from the frontal electrodes was analyzed with spectral analysis and the results were compared against the reports in the literature. Results: The signal captured with frontal electrodes, particularly α rhythm, enabled the distinction between resting with eyes closed and with eyes opened in a conscious state, and sustained anesthesia during surgery. Conclusions: It is possible to differentiate a resting state from sustained anesthesia, replicating previous findings with conventional technologies. These results pave the way to the use of portable technologies such as the OpenBCI tool, to explore the brain dynamics during anesthesia.

scholarly journals Effects of circadian rhythm on Narcotrend index and target-controlled infusion concentration of propofol anesthesia

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jiang-hua Shen ◽  
Min Ye ◽  
Qian Chen ◽  
Yan Chen ◽  
Hai-lin Zhao ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
General Anesthesia ◽  
Closed Loop ◽  
Depth Of Anesthesia ◽  
Drug Infusion ◽  
Anesthetic Depth ◽  
Time Points ◽  
Target Controlled Infusion ◽  
Medical University ◽  
Narcotrend Index

Abstract Background The effects of circadian rhythms on drug metabolism and efficacy are being increasingly recognized. However, the extent to which they affect general anesthesia remains unclear. This study aims to investigate the effects of circadian rhythms on anesthetic depth and the concentrations of propofol target-controlled infusion (TCI). Methods Sixty patients undergoing laparoscopic surgeries were sequentially assigned to four groups. Group ND (n = 15): Propofol TCI with Narcotrend monitor during the day (8:00–18:00), Group NN (n = 15): Propofol TCI with Narcotrend monitor during the night (22:00–5:00), Group CLTD (n = 15): Propofol closed-loop TCI guided by bispectral index (BIS) during the day (8:00–18:00), Group CLTN (n = 15): Propofol closed-loop TCI guided by BIS during the night (22:00–5:00). The Narcotrend index, mean arterial pressure (MAP) and heart rate (HR) were compared between group ND and NN at 7 time points, from 5 min before induction to the end of operation. The propofol TCI concentrations, MAP and HR were compared between group CLTD and CLTN at 7 time points, from 5 min after induction to the end of operation. Results The Narcotrend index, MAP, and HR in group NN were lower than those in group ND from the beginning of mechanical ventilation to the end of operation (p < 0.05). The propofol TCI concentrations in group CLTN were lower than those in group CLTD from the beginning of operation to the end of operation (p < 0.05). Conclusion Circadian rhythms have a significant effect on the depth of anesthesia and drug infusion concentrations during propofol TCI. When using general anesthesia during night surgery, the propofol infusion concentration should be appropriately reduced compared to surgery during the day. Trial registration The present study was registered on the ClinicalTrials.gov website (NCT02440269) and approved by the Medical Ethics Committee of Southwest Hospital of Third Military Medical University (ethics lot number: 2016 Research No. 93). All patients provided informed written consent to participate in the study.

scholarly journals Reconfiguration of Network Hub Structure after Propofol-induced Unconsciousness

2013 ◽  
Vol 119 (6) ◽  
pp. 1347-1359 ◽  
Author(s):  
Heonsoo Lee ◽  
George A. Mashour ◽  
Gyu-Jeong Noh ◽  
Seunghwan Kim ◽  
UnCheol Lee
Keyword(s):  
General Anesthesia ◽  
Brain Networks ◽  
Phase Relationship ◽  
Clustering Coefficient ◽  
Phase Lag ◽  
Hub Location ◽  
Functional Brain ◽  
Functional Changes ◽  
States Of Consciousness ◽  
Functional Brain Network

Abstract Introduction: General anesthesia induces unconsciousness along with functional changes in brain networks. Considering the essential role of hub structures for efficient information transmission, the authors hypothesized that anesthetics have an effect on the hub structure of functional brain networks. Methods: Graph theoretical network analysis was carried out to study the network properties of 21-channel electroencephalogram data from 10 human volunteers anesthetized on two occasions. The functional brain network was defined by Phase Lag Index, a coherence measure, for three states: wakefulness, loss of consciousness induced by the anesthetic propofol, and recovery of consciousness. The hub nodes were determined by the largest centralities. The correlation between the altered hub organization and the phase relationship between electroencephalographic channels was investigated. Results: Topology rather than connection strength of functional networks correlated with states of consciousness. The average path length, clustering coefficient, and modularity significantly increased after administration of propofol, which disrupted long-range connections. In particular, the strength of hub nodes significantly decreased. The primary hub location shifted from the parietal to frontal region, in association with propofol-induced unconsciousness. The phase lead of frontal to parietal regions in the α frequency band (8–13 Hz) observed during wakefulness reversed direction after propofol and returned during recovery. Conclusions: Propofol reconfigures network hub structure in the brain and reverses the phase relationship between frontal and parietal regions. Changes in network topology are more closely associated with states of consciousness than connectivity and may be the primary mechanism for the observed loss of frontal to parietal feedback during general anesthesia.

Effects of Adjuvant Ketamine on Induction of Anesthesia for the Cesarean Section

2020 ◽  
Vol 15 ◽  
Author(s):  
Mahmoudreza Moradkhani ◽  
Siavash Beiranvand ◽  
Sedigheh Nadri ◽  
Paridokht Hejri
Keyword(s):  
Cesarean Section ◽  
General Anesthesia ◽  
Low Doses ◽  
Depth Of Anesthesia ◽  
Intraoperative Awareness ◽  
The Past ◽  
Group A ◽  
Group B ◽  
Larger Sample ◽  
Intravenous Ketamine

Background: The cesarean section has shown an increase in the trends within the past few years. The use of appropriate and effective anesthesia for the procedure is important, not only to reduce the incidence of maternal and fetal morbidities but also to reduce the incidence of intraoperative awareness. objective: The aim of this study is to evaluate the intraoperative and postoperative effects of adjuvant ketamine, when used in combination with general anesthesia. Objective: The aim of this study is to evaluate the intraoperative and postoperative effects of adjuvant ketamine, when used in combination with general anesthesia. Methods: The study was conducted on the patients referred to Asali hospital for the cesarean section. 100 patients were assigned to two groups. Patients in Group A received thiopental (4 mg / kg) as an anesthetic agent for the surgery whereas; those in group B received thiopental along with 0.5 mg / kg of intravenous ketamine. The effects of ketamine such as, depth of anesthesia, intraoperative and postoperative awareness, vomiting and hallucination were recorded in the questionnaire and data were statistically analyzed using SPSS v25. Results: Of 100 patients in group A, 10 of them were not deeply unconscious. 40 patients in group A and 25 in group B had intraoperative awareness. 1 patient in group A and 3 in group B had vomiting and 1 patient in group B was presented with the hallucinations. Conclusion: Overall use of ketamine is associated with better sedation and no significant side effects with low doses of ketamine, were seen in our study. Comparative studies using other analgesics, with larger sample size are therefore recommended.

Utilization of Pleth Index in Hysteroscopic Surgery: A Randomized Controlled Trial

2020 ◽  
Author(s):  
Lifeng Yao ◽  
Changshun Huang ◽  
Jungang Zheng ◽  
Yong Li
Keyword(s):  
General Anesthesia ◽  
Controlled Trial ◽  
Depth Of Anesthesia ◽  
Hysteroscopic Surgery ◽  
Bodily Movement ◽  
Anesthetic Drugs ◽  
Recovery Times ◽  
Monitoring Group ◽  
Group B ◽  
Intraoperative Movement

Abstract Background: When performing hysteroscopic surgery under general anesthesia in non-intubated patients, anesthesiologists and gynecologists face challenges including patient movement and respiratory depression due to variability in the depth of patient anesthesia. Intraoperative modulation of the depth of anesthesia is dictated by clinical practice. In recent years, the noninvasive surgical pleth index (SPI) has been purported to objectively reflect the depth of anesthesia. In the present study, we investigated the performance of SPI monitoring in hysteroscopic surgery.Methods: Eighty patients scheduled for hysteroscopic surgery under general anesthesia with a laryngeal mask airway (i.e., spontaneous ventilation without a muscle relaxant) were randomly divided into two groups (both n = 40): (1) bispectral index (BIS)- and SPI-monitoring group (BS Group); and (2) BIS-monitoring group (B group). Intraoperative analgesia was provided via target-controlled infusion (TCI) of remifentanil, which was modulated according to the SPI value (target interval, 20–50) in the BS Group or via the anesthesiologist's assessment in the B Group. In both groups, anesthesia was administered to maintain the BIS values between 40–60. Additionally, the incidences and degree of movement, consumption of anesthetic drugs, recovery times, complications, and satisfactory levels were compared between the two groups.Results: The incidence and degree of bodily movement in the BS Group were significantly lower than those in the B Group (P < 0.05). Furthermore, the remifentanil induction dose and recovery time in the BS group were significantly lower than those in the B group (P < 0.05). However, there were no significant differences between the two groups with regard to adverse events including nausea, vomiting, and dizziness. Finally, gynecologists had higher satisfactory levels in the BS Group (P < 0.05).Conclusion: SPI- and BIS-guided general anesthesia is clinically feasible in hysteroscopic surgery and leads to both inhibition of intraoperative movement and faster recovery.

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