Awareness and Perspectives among Asian Anesthesiologists on Postoperative Delirium: A Multinational Survey

Postoperative delirium (POD) is a common perioperative complication. Although POD is preventable in up to 40% of patients, it is frequently overlooked. The objective of the survey is to determine the level of knowledge and clinical practices related to POD among anesthesiologists in different Asian countries. A questionnaire of 22 questions was designed by members of the Asian focus group for the study of POD, and it was sent to anesthesiologists in Singapore, Thailand, and South Korea from 1 April 2019 through 17 September 2019. In total, 531 anesthesiologists (Singapore: 224, Thailand: 124, Korea: 183) responded to the survey. Half the respondents estimated the incidence of POD to be 11–30% and believed that it typically occurs in the first 48 h after surgery. Among eight important postoperative complications, POD was ranked fifth. While 51.4% did not perform any test for POD, only 13.7% monitored the depth of anesthesia in all their patients. However, 83.8% preferred depth of anesthesia monitoring if they underwent surgery themselves. The results suggest that Asian anesthesiologists underestimate the incidence and relevance of POD. Because it increases perioperative mortality and morbidity, there is an urgent need to educate anesthesiologists regarding the recognition, prevention, detection, and management of POD.

Preliminary study on the potential of topical anaesthesia from betel leaf and clove leaf extract

Introduction: Betel leaf (Piper betle Linn.) and clove leaf (Syzygium aromaticum) are Indonesian herbs which are known to cause a numb sensation. The main ingredients of betel leaf, which act as an anesthetic, are caryophyllene, eugenol, methyl eugenol, eucalyptol (1.8-cineol), linalool, α-Pinene, estragole, while cloves have local anesthetic effects through their ingredients, namely eugenol, and β-Caryophyllene. Research on the benefits of these two ingredients as topical anesthetics in Indonesia is still rare. This study was aimed to describe the potential of betel leaf and clove leaf extract as a topical anesthetic in Wistar rats. Methods: This research was a laboratory experimental research with simple randomized controlled design. The sample consisted of 6 male Wistar rats, each of which was given four treatments, namely extract with a concentration of 50%, 75%, and 100%, and topical anaesthetic benzocaine 20% as a control. Each treatment was tested using an electric stimulator and observed onset, duration of action, and depth of topical anaesthesia. The data were processed using descriptive statistics with tables and graphs. Results: Betel leaf extract with a concentration of 100% had a better mean onset, duration of work, and depth of anesthesia than the 20% benzocaine control, whereas 75% clove leaf extract had the longest duration of action compared to 20% benzocaine and 100% concentration was the topical anesthetic agent with the highest anesthetic depth. Conclusion: Based on the onset, duration of action, and depth of anesthesia, betel leaf, and clove leaf have potential as topical anesthetic agents.

Effect of Bispectral Index-Guided Total Intravenous Anesthesia on Post-Anesthetic Recovery Outcomes in High-Risk Children: A Prospective, Randomized, Controlled Trial

BACKGROUND TIVA is widely used in children, but few studies have attempted to evaluation of the effect of BIS-guided propofol infusion than that on conventional methods on recovery outcomes in children with higher risk factors.OBJECTIVETo evaluate the effect of bispectral index (BIS) guidance during total intravenous anesthesia on post-anesthetic recovery outcomes in children at higher risk during anesthesia. DESIGNA prospective, randomized, controlled trial. SETTING University medical centre.PATIENTSThis study enrolled 472 children (aged 1-14 years) who met the higher-risk scoring criteria and were scheduled for surgery under total intravenous anesthesia. INTERVENTIONThe children were randomly assigned to the BIS group (group B) and standard clinical practice group (group S). The BIS values in group B were maintained at 45–60. The anesthesiologist controlled the depth of anesthesia in group S according to the variation in the clinical signs of the children. MAIN OUTCOME MEASURESBIS values, heart rate (HR), mean arterial pressure (MAP), and pulse oxygen saturation at each time points, as well as the time between drug withdrawal to extubation, duration of stay in the post-anesthesia care unit (PACU), the total amount of propofol used, and postoperative adverse reactions were recorded. RESULTSThere was no significant difference in time from stopping propofol infusion to extubation and duration of PACU between the groups . There was no significant difference in BIS values between the groups at T2, T3, and T8. BIS values at T1, T4, T5, T6, and T7 in group B were lower than those in group S. There was no statistically significant difference in the HR between the groups. MAP in group B was lower than in group S at T5, T6, T7, and T8. The total amount of propofol administered in group B was higher than in group S. CONCLUSIONThe use of BIS-guided total intravenous anesthesia in higher-risk children can maintain the proper depth of anesthesia but does not prolong the time of extubation and the duration of stay in the PACU.TRIAL REGISTRATION Chictr.org.cn identifier: 24/11/2017 , ChiCTR-IOR-17013530

Electroencephalogram variability analysis for monitoring depth of anesthesia

In this paper, a new approach of extracting and measuring the variability in electroencephalogram (EEG) was proposed to assess the depth of anesthesia (DOA) under general anesthesia. The EEG variability (EEGV) was extracted as a fluctuation in time interval that occurs between two local maxima of EEG. Eight parameters related to EEGV were measured in time and frequency domains, and compared with state-of-the-art DOA estimation parameters, including sample entropy, permutation entropy, median frequency and spectral edge frequency of EEG. The area under the receiver-operator characteristics curve (AUC) and Pearson correlation coefficient were used to validate its performance on 56 patients. Our proposed EEGV-derived parameters yield significant difference for discriminating between awake and anesthesia stages at a significance level of 0.05, as well as improvement in AUC and correlation coefficient on average, which surpasses the conventional features of EEG in detection accuracy of unconscious state and tracking the level of consciousness. To sum up, EEGV analysis provides a new perspective in quantifying EEG and corresponding parameters are powerful and promising for monitoring DOA under clinical situations.

Lipid Emulsion And Isoflurane: The Quality Assessment of Anesthesia Parameters In Pigeons

An objective was to evaluate the efficacy of intravenous (IV) emulsified isoflurane formulation for maintenance of general anesthesia and to compare with IV lipid emulsion infusion with inhalation isoflurane in pigeons. The animals was total of 21 healthy, mature pigeons (Columba livia domestica), weighing 318 ± 13 g. Pigeons were anesthetized by emulsified isoflurane (treatment IΙΙ), inhalation isoflurane with IV lipid emulsion (treatment ΙΙ ), and inhalation isoflurane (treatment Ι) alone. Over 50 minutes, wing tone, toe pinch (pedal), and feather pluck reflex were tested every 10 minutes. Data was recorded at 10, 20 and 30 minutes for temperature (T), peripheral hemoglobin oxygen saturation (SpO2) heart rate (HR), and respiratory rate (fR). A scoring system was used to assess parameters related to anesthesia duration and depth. There were no significant differences in hemodynamic variables between the treatment Ι and treatments ΙΙ and IΙΙ, in treatments associated with fat emulsion have shown faster induction, longer anesthesia, more immobilization, and longer recovery time. Furthermore, in anesthesia depth percentages evaluation it was observed that emulsified isoflurane entered the anesthesia deep stage earlier and was removed immediately after discontinuation of administration.Administration of 8% v/v emulsified isoflurane IV was effective in anesthesia rapid induction, stability in depth of anesthesia, rapid withdrawal from anesthesia depth by discontinuation of the infusion, delayed recovery, cardiorespiratory and (T) stability.

Monitoring of Anesthesia by Bispectral Analysis of EEG Signals

Background. In intensive care, monitoring the depth of anesthesia during surgical procedures is a key element in the success of the medical operation and postoperative recovery. However, despite the development of anesthesia thanks to technological and pharmacological advances, its side effects such as underdose or overdose of hypnotics remain a major problem. Observation and monitoring must combine clinical observations (loss of consciousness and reactivity) with tools for real-time measurement of changes in the depth of anesthesia. Methodology. In this work, we will develop a noninvasive method for calculating, monitoring, and controlling the depth of general anesthesia during surgery. The objective is to reduce the effects of pharmacological usage of hypnotics and to ensure better quality recovery. Thanks to the overall activity of sets of neurons in the brain, we have developed a BIS technique based on bispectral analysis of the electroencephalographic signal EEG. Discussion. By collecting the electrical voltages from the brain, we distinguish light sleep from deep sleep according to the values of the BIS indicator (ranging from 0 : sleep to 100 : wake) and also control it by acting on the dosage of propofol and sevoflurane. We showed that the BIS value must be maintained during the operation and the anesthesia at a value greater than 60. Conclusion. This study showed that the BIS technology led to an optimization of the anesthetic management, the adequacy of the hypnotic dosage, and a better postoperative recovery.

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

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.

Time-Frequency Analysis of EEG Signals and GLCM Features for Depth of Anesthesia Monitoring

One of the important tasks in the operating room is monitoring the depth of anesthesia (DoA) during surgery, and noninvasive techniques are very popular. Hence, we propose a new scheme for DoA monitoring considering the time-frequency analysis of electroencephalography (EEG) signals and GLCM features extracted from them. To this end, at first, the time-frequency map (TFM) of each channel of each EEG is computed by smoothed pseudo-Wigner–Ville distribution (SPWVD), where the EEG signal used in this paper is recorded in 15 channels. After that, we consider the gray-level co-occurrence matrix (GLCM) to obtain the content of TFM, and after that, four features such as homogeneity, correlation, energy, and contrast are obtained for each GLCM. Finally, after the selection of efficient features using the minimum redundancy maximum relevance (MRMR) method, the K-nearest neighbor (KNN) classifier is utilized to determine the DoA. Here, we consider the three states, namely, deep hypnotic, surgical anesthesia, and sedation and awake states according to bispectral index (BIS), and each EEG epoch is classified to these states. We also employ data augmentation to enhance the training phase and increase accuracy. We obtain the accuracy and confusion matrix of the proposed method. We also analyze the effects of a number of gray levels of GLCM, distance measure in KNN classifier, and parameters of data augmentation on the performance of the proposed method. Results indicate the efficiency of the proposed method to determine the DoA during surgery.

Adequacy of maternal anesthesia depth with two sodium thiopental doses in elective caesarean section: a randomized clinical trial

Background Administration of an optimal dose of anesthetic agent to ensure adequate depth of hypnosis with the lowest risk of adverse effects to the fetus is highly important in cesarean section. Sodium thiopental (STP) is still the first choice for induction of anesthesia in some countries for this obstetric surgery. We aimed to compare two doses of STP with regarding the depth of anesthesia and the condition of newborn infants. Methods In this clinical trial, parturient undergoing elective Caesarian section were randomized into two groups receiving either low-dose (5 mg/kg) or high-dose (7 mg/kg) STP. Muscle relaxation was provided with succinylcholine 2 mg/kg and anesthesia was maintained with O2/N2O and sevoflurane. The depth of anesthesia was evaluated using isolated forearm technique (IFT) and bispectral index (BIS) in various phases. Additionally, infants were assessed using Apgar score and neurobehavioral test. Results Forty parturient were evaluated in each group. BIS was significantly lower in high-dose group at skin incision to delivery and subcutaneous and skin closure. Also, significant differences were noticed in IFT over induction to incision and incision to delivery. Apgar score was significantly lower in high-dose group at 1 min after delivery. Newborn infants in low-dose group had significantly better outcomes in all three domains of the neurobehavioral test. Conclusion 7 mg/kg STP is superior to 5 mg/kg in creating deeper hypnosis for mothers. However, it negatively impacts Apgar score and neurobehavioral test of neonates. STP seems to has dropped behind as an acceptable anesthetic in Cesarean section. Trial registration IRCT No: 2016082819470 N45, 13/03/2019.