Incidence, Associated Factors, and Behavioral Consequences of Intraoperative Awareness and Dreams During General Anesthesia Among Adult Patients: A Prospective Cohort Study.

Background  The intraoperative awareness with recall phenomenon involves the memory of intraoperative events. The reported incidence is 0.001%. Awareness is rare intraoperatively but has profound implications. This research aimed to study intraoperative awareness and dream experiences in the Omani population undergoing general anesthesia. Methods This prospective cohort study involving 300 adult patients was conducted at a tertiary-level hospital between July and December 2021. Awareness was assessed in the post-anesthesia care unit and then at home on the seventh day and one month telephonically using a modified Brice questionnaire. The study's primary outcome was the incidence of IOA and dreams in adult Omani patients undergoing GA. The secondary outcome was identifying the factors associated with intraoperative awareness and dreams under GA. Results In this study, the incidence of awareness was 0.3% while 7.6% of patients reported intraoperative dreams. The patient who experienced IOA underwent an endoscopic retrograde cholangiopancreatography under GA with neuromuscular blockade and had a prolonged recovery. A total of 49.33% developed psychological effects postoperatively; anxiety, irritability, fear of surgery, change in memory, and repetitive nightmares were the most common ones. Because of the limited sample size, no factor associated significantly with these outcomes was found. Conclusion This study observed a higher incidence of intraoperative awareness and dreams. Awareness might be due to prolonged recovery and the use of neuromuscular blocking agents, but a focused study is required to confirm this finding. The incidence of intraoperative dreams and postoperative psychological effects of GA was also high. It may be worth exploring these findings with larger population-based research.

Impact of female sex on anaesthetic awareness, depth, and emergence: a systematic review and meta-analysis.

BACKGROUND: Suggested anaesthetic dose ranges do not differ by sex, likely because of limited studies comparing sexes. Our objective was to systematically synthesise studies with outcomes of unintended anaesthesia awareness under anaesthesia, intraoperative connected consciousness, time to emergence from anaesthesia, and dosing to achieve adequate depth of anaesthesia, and to compare between females and males. METHODS: Studies were identified from MEDLINE, Embase, and the Cochrane library databases until August 2, 2022. Controlled clinical trials (randomised/non-randomised) and prospective cohort studies that reported outcomes by sex were included. Results were synthesised by random effects meta-analysis where possible, or narrative form. RESULTS: Of the 19 749 studies identified, 64 (98 243 participants; 53 143 females and 45 100 males) were eligible for inclusion, and 44 citations contributed to meta-analysis. Females had a higher incidence of awareness with postoperative recall (33 studies, odds ratio 1.38, 95% confidence interval [CI] 1.09-1.75) and connected consciousness during anaesthesia (three studies, OR 2.09, 95% CI 1.04-4.23) than males. Time to emergence was faster in females, including time to eye-opening (10 studies, mean difference -2.28 min, 95% CI -3.58 to -0.98), and time to response to command (six studies, mean difference -2.84 min, 95% CI -4.07 to -1.62). Data on depth of anaesthesia were heterogenous, limiting synthesis to a qualitative review which did not identify sex differences. CONCLUSIONS: Female sex was associated with a greater incidence of awareness under general anaesthesia, and faster emergence from anaesthesia. These data suggest reappraisal of anaesthetic care, including whether similar drug dosing for females and males represents best care. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42022336087.

Detection of Motor Cerebral Activity After Median Nerve Stimulation During General Anesthesia (STIM-MOTANA): Protocol for a Prospective Interventional Study.

BACKGROUND: Accidental awareness during general anesthesia (AAGA) is defined as an unexpected awareness of the patient during general anesthesia. This phenomenon occurs in 1%-2% of high-risk practice patients and can cause physical suffering and psychological after-effects, called posttraumatic stress disorder. In fact, no monitoring techniques are satisfactory enough to effectively prevent AAGA; therefore, new alternatives are needed. Because the first reflex for a patient during an AAGA is to move, but cannot do so because of the neuromuscular blockers, we believe that it is possible to design a brain-computer interface (BCI) based on the detection of movement intention to warn the anesthetist. To do this, we propose to describe and detect the changes in terms of motor cortex oscillations during general anesthesia with propofol, while a median nerve stimulation is performed. We believe that our results could enable the design of a BCI based on median nerve stimulation, which could prevent AAGA. OBJECTIVE: To our knowledge, no published studies have investigated the detection of electroencephalographic (EEG) patterns in relation to peripheral nerve stimulation over the sensorimotor cortex during general anesthesia. The main objective of this study is to describe the changes in terms of event-related desynchronization and event-related synchronization modulations, in the EEG signal over the motor cortex during general anesthesia with propofol while a median nerve stimulation is performed. METHODS: STIM-MOTANA is an interventional and prospective study conducted with patients scheduled for surgery under general anesthesia, involving EEG measurements and median nerve stimulation at two different times: (1) when the patient is awake before surgery (2) and under general anesthesia. A total of 30 patients will receive surgery under complete intravenous anesthesia with a target-controlled infusion pump of propofol. RESULTS: The changes in event-related desynchronization and event-related synchronization during median nerve stimulation according to the various propofol concentrations for 30 patients will be analyzed. In addition, we will apply 4 different offline machine learning algorithms to detect the median nerve stimulation at the cerebral level. Recruitment began in December 2022. Data collection is expected to conclude in June 2024. CONCLUSIONS: STIM-MOTANA will be the first protocol to investigate median nerve stimulation cerebral motor effect during general anesthesia for the detection of intraoperative awareness. Based on strong practical and theoretical scientific reasoning from our previous studies, our innovative median nerve stimulation-based BCI would provide a way to detect intraoperative awareness during general anesthesia. TRIAL REGISTRATION: Clinicaltrials.gov NCT05272202; https://clinicaltrials.gov/ct2/show/NCT05272202. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/43870.

Effect of perioperative benzodiazepine use on intraoperative awareness and postoperative delirium: a systematic review and meta-analysis of randomised controlled trials and observational studies.

BACKGROUND: Benzodiazepine use is associated with delirium, and guidelines recommend avoiding them in older and critically ill patients. Their perioperative use remains common because of perceived benefits. METHODS: We searched CENTRAL, MEDLINE, CINAHL, PsycInfo, and Web of Science from inception to June 2021. Pairs of reviewers identified randomised controlled trials and prospective observational studies comparing perioperative use of benzodiazepines with other agents or placebo in patients undergoing surgery. Two reviewers independently abstracted data, which we combined using a random-effects model. Our primary outcomes were delirium, intraoperative awareness, and mortality. RESULTS: We included 34 randomised controlled trials (n=4354) and nine observational studies (n=3309). Observational studies were considered separately. Perioperative benzodiazepines did not increase the risk of delirium (n=1352; risk ratio [RR] 1.43; 95% confidence interval [CI]: 0.9-2.27; I2=72%; P=0.13; very low-quality evidence). Use of benzodiazepines instead of dexmedetomidine did, however, increase the risk of delirium (five studies; n=429; RR 1.83; 95% CI: 1.24-2.72; I2=13%; P=0.002). Perioperative benzodiazepine use decreased the risk of intraoperative awareness (n=2245; RR 0.26; 95% CI: 0.12-0.58; I2=35%; P=0.001; very low-quality evidence). When considering non-events, perioperative benzodiazepine use increased the probability of not having intraoperative awareness (RR 1.07; 95% CI: 1.01-1.13; I2=98%; P=0.03; very low-quality evidence). Mortality was reported by one randomised controlled trial (n=800; RR 0.90; 95% CI: 0.20-3.1; P=0.80; very low quality). CONCLUSIONS: In this systematic review and meta-analysis, perioperative benzodiazepine use did not increase postoperative delirium and decreased intraoperative awareness. Previously observed relationships of benzodiazepine use with delirium could be explained by comparisons with dexmedetomidine. SYSTEMATIC REVIEW PROTOCOL: PROSPERO CRD42019128144.

Perception and practices of depth of anesthesia monitoring and intraoperative awareness event rate among Jordanian anesthesiologists: a cross-sectional study.

BACKGROUND: Intraoperative awareness is the second most common complication of surgeries, and it negatively affects patients and healthcare professionals. Based on the limited previous studies, there is a wide variation in the incidence of intraoperative awareness and in the practices and attitudes toward depth of anesthesia (DoA) monitoring among healthcare systems and anesthesiologists. This study aimed to evaluate the Jordanian anesthesiologists' practice and attitudes toward DoA monitoring and estimate the event rate of intraoperative awareness among the participating anesthesiologists. METHODS: A descriptive cross-sectional survey of Jordanian anesthesiologists working in public, private, and university hospitals was utilized using a questionnaire developed based on previous studies. Practice and attitude in using DoA monitors were evaluated. Anesthesiologists were asked to best estimate the number of anesthesia procedures and frequency of intraoperative awareness events in the year before. Percentages and 95% Confidence Intervals (95%CI) were reported and compared between groups using chi-square tests. RESULTS: A total of 107 anesthesiologists responded and completed the survey. About one-third of the respondents (34.6%; 95% CI 26.1-44.2) had never used a DoA monitor and only 6.5% (95% CI 3.1-13.2) reported using it as a "daily practice". The use of a DoA monitor was associated with experience and type of health sector. However, 81.3% (95% CI 66.5-83.5) believed that currently available DoA monitors are effective for DoA monitoring and only 4.7% (95%CI 1.9-10.8) reported it as being "invalid". Most respondents reported that the main purpose of using a DoA monitor was to prevent awareness (86.0%; 95%CI 77.9-91.4), guide the delivery of anesthetics (63.6%; 95%CI 53.9-72.2), and reduce recovery time (57%; 95%CI 47.4-66.1). The event rate of intraoperative awareness was estimated at 0.4% among participating anesthesiologists. Most Jordanian hospitals lacked policy intending to prevent intraoperative awareness. CONCLUSIONS: Most anesthesiologists believed in the role of DoA monitors in preventing intraoperative awareness, however, their attitudes and knowledge are inadequate, and few use DoA monitors in routine practices. In Jordan, large efforts are needed to regulate the use of DoA monitoring and reduce the incidence of intraoperative awareness.

[What's new Patients are listening-communication under general anesthesia]. / Was ist neu Patienten hören mit ­ Kommunikation während Narkose.

There is ample evidence of awareness of at least some unconscious patients. A recent multicenter study found significant reductions after therapeutic communication during general anesthesia in postoperative pain and analgesic consumption, as well as in postoperative nausea and vomiting (PONV) and antiemetic requirements in high-risk patients. Thus, an intraoperatively presentet text represents a simple non-pharmacological method to reduce side effects of surgery and anesthesia. This also offers treatment in other unconscious patients. However, another finding seems worth noting: the results of the study cannot be explained by the known intraoperative awareness and response of individual patients. Therefore, there should be a fundamental change in the way patients are treated in the operating room and intensive care unit, and background noise and careless conversations should be eliminated. 56 years after David Cheek formulated "BE CAREFUL, THE PATIENT IS LISTENING should be engraved over the door of every operating room, every recovery room, every intensive care unit in every hospital." after his first observations of patient perceptions, perhaps it is now time to finally heed this call and to use communication with unconscious patients that goes beyond the most necessary announcement of interventions and is therapeutically effective through positive suggestions. When in doubt, assume that the patient is listening.

Intraoperative Awareness in Patients Undergoing Cardiac Surgery in an Academic Center in the North of Iran.

Background: Coronary artery bypass grafting (CABG) has distinctive characteristics that may increase the risk of awareness during general anesthesia (AGA). Objectives: This study was conducted to assess the incidence of AGA in cardiac surgery in an academic hospital in Guilan, Iran. Methods: This descriptive cross-sectional study was performed in Dr. Heshmat Hospital in Rasht, Iran. Eligible patients candidates for CABG were enrolled in the survey in 2022. After surgery, when the patient was cooperative enough, a questionnaire including demographic data and specialized questions related to different stages of anesthesia was completed via face-to-face interviews. The data were analyzed using IBM SPSS Statistics 21 with chi-square, Fisher's exact, and t-test. Results: The data from 322 patients were analyzed, of whom 14 (4.3%) experienced AGA. Among them, the "feeling of fear and anxiety" reported by 9 (39.1%) cases was the most common awareness state. "Dreaming during surgery and anesthesia" and "feeling unable to move during anesthesia,", each reported by 6 (26.1%) cases, were the other common types of awareness state. None of the demographic data had a significant association with the occurrence of AGA. Conclusions: The incidence of AGA during CABG was almost acceptable according to the credible evidence.

Detection method of intraoperative awareness: a randomized comparative study.

BACKGROUND: : The incidence of intraoperative awareness varies in a wide range in the literature. The reasons for these different results include the questioning method used and the questioning time. The goal of this study is to compare the effectiveness of different questioning methods and times used in intraoperative awareness research for detecting the incidence. METHODS: We recruited patients between the ages of 18-70 years, with normal cognitive functions and able to speak after general anesthesia to the study. The patients were randomly divided into two groups. In Group 1 we applied the modified Brice questionnaire in the first 2 h and 24 h after surgery for investigating intraoperative awareness. In Group 2, 24 h after surgery, we asked about anesthesia satisfaction and patients' complaints, if any. RESULTS: There was no statistically significant difference between the groups in terms of age (p = 0.514).The proportion of women was significantly higher (p = 0.002), the duration of anesthesia was shorter, and the rate of narcotic analgesic use was higher in Group 2 (p < 0.001). The assessment in the first 2 h showed the frequency of awareness was statistically higher in Group 1 than in Group 2 (p = 0.016). In the postoperative 24-h assessment, we found no significant difference in the incidence of intraoperative awareness between the groups (p < 0.05). In Group 1, there was no statistically significant difference in terms of incidence of awareness according to evaluation time (p = 250). DISCUSSION: The incidence of intraoperative awareness in Group 1 was significantly higher than in Group 2 in the evaluation conducted in the first 2 h. There was no significant difference in the determination of intraoperative awareness between questioning times in group 1.

Raw and processed electroencephalography in modern anesthesia practice: a brief primer on select clinical applications.

The evidence supporting the intraoperative use of processed electroencephalography (pEEG) monitoring to guide anesthetic delivery is growing rapidly. This article reviews the key features of electroencephalography (EEG) waveforms and their clinical implications in select patient populations and anesthetic techniques. The first patient topic reviewed is the vulnerable brain. This term has emerged as a description of patients who may exhibit increased sensitivity to anesthetics and/or may develop adverse neurocognitive effects following anesthesia. pEEG monitoring of patients who are known to have or are suspected of having vulnerable brains, with focused attention on the suppression ratio, alpha band power, and pEEG indices, may prove useful. Second, pEEG monitoring along with vigilant attention to anesthetic delivery may minimize the risk of intraoperative awareness when administering a total intravenous anesthesia in combination with a neuromuscular blockade. Third, we suggest that processed EEG monitoring may play a role in anesthetic and resuscitative management when adverse changes in blood pressure occur. Fourth, pEEG monitoring can be used to better identify anesthesia requirements and guide anesthetic titration in patients with known or suspected substance use.

[Inhalational anesthetics]. / Inhalationsanästhetika.

Inhalational anesthetics have been used for induction and maintenance of general anesthesia for more than 150 years. All of the currently used inhalational anesthetics are chlorinated and fluorinated derivatives of ether. Dosing is carried out using the minimal alveolar concentration (MAC) concept. The pharmacokinetic properties of the various inhalational anesthetics are governed by the specific distribution coefficients. Mechanisms of action include specific modulations of various receptors of the central nervous system as well as an unspecific interaction with the cell membrane. Organ toxicity of modern inhalational anesthetics is considered to be minimal. The role of inhalational anesthetics in the context of postoperative nausea and vomiting (PONV) has been reassessed in recent years. The superiority of inhalational anesthetics over intravenous hypnotics with respect to intraoperative awareness is undisputed. The organ protective mechanism of preconditioning is an exclusive property of inhalational anesthetics among all the currently available hypnotics.

Frontal electroencephalogram reveals emergence-like brain activity occurring during transition periods in cardiac surgery.

BACKGROUND: Cardiac surgery has one of the highest incidences of intraoperative awareness. The periods of initiation and discontinuation of cardiopulmonary bypass could be high-risk periods. Certain frontal EEG patterns might plausibly occur with unintended intraoperative awareness. This study sought to quantify the incidence of these pre-specified patterns during cardiac surgery. METHODS: Two-channel bihemispheric frontal EEG was recorded in 1072 patients undergoing cardiac surgery as part of a prospective observational study. Spectrograms were created, and mean theta (4-7 Hz) power and peak alpha (7-17 Hz) frequency were measured in patients under general anaesthesia with isoflurane. Emergence-like EEG activity in the spectrogram during surgery was classified as an alpha peak frequency increase by 2 Hz or more, and a theta power decrease by 5 dB or more in comparison with the median pre-bypass values. RESULTS: Data from 1002 patients were available for analysis. Fifty-five of those patients (5.5%) showed emergence-like EEG activity at least once during surgery with a median duration of 13.2 min. These patients were younger (median age, 59 vs 67 yr; P<0.001) and the median end-tidal isoflurane concentration before cardiopulmonary bypass was higher (0.82 vs 0.75 minimum alveolar concentration [MAC]; P=0.013). There was no significant difference between those with or without emergence-like EEG activity in sex, lowest core temperature, or duration of surgery. Forty-six of these EEG changes (84%) occurred within a 1 h time window centred on separation from cardiopulmonary bypass. CONCLUSION: The findings of this study suggest that approximately one in 20 patients undergoing cardiac surgery with a volatile anaesthetic agent have a sustained EEG pattern while surgery is ongoing that is often seen with emergence from general anaesthesia. Monitoring the frontal EEG during cardiopulmonary bypass may identify these events and potentially reduce the incidence of unintended awareness. CLINICAL TRIAL REGISTRATION: NCT02976584.

Retrospective analysis of cases of intraoperative awareness in a large multi-hospital health system reported in the early postoperative period.

BACKGROUND: Awareness with recall under general anesthesia remains a rare but important issue that warrants further study. METHODS: We present a series of seven cases of awareness that were identified from provider-reported adverse event data from the electronic anesthesia records of 647,000 general anesthetics. RESULTS: The low number of identified cases suggests an under-reporting bias. Themes that emerge from this small series can serve as important reminders to anesthesia providers to ensure delivery of an adequate anesthetic for each patient. Commonalities between a majority of our identified anesthetic awareness cases include: obesity, use of total intravenous anesthesia, use of neuromuscular blockade, and either a lack of processed electroencephalogram (EEG) monitoring or documented high depth of consciousness index values. An interesting phenomenon was observed in one case, where adequately-dosed anesthesia was delivered without technical issue, processed EEG monitoring was employed, and the index value suggested an adequate depth of consciousness throughout the case. CONCLUSIONS: Provider-reported adverse event data in the immediate post-operative period are likely insensitive for detecting cases of intraoperative awareness. Though causation cannot firmly be established from our data, themes identified in this series of cases of awareness with recall under general anesthesia provide important reminders for anesthesia providers to maintain vigilance in monitoring depth and dose of anesthesia, particularly with total intravenous anesthesia.

Awareness during emergence from anesthesia: Features and future research directions.

The anesthesia awareness with recall (AAWR) phenomenon represents a complication of general anesthesia consisting of memorization of intraoperative events reported by the patient immediately after the end of surgery or at a variable distance from it. Approximately 20% of AAWR cases occur during emergence from anesthesia. Clinically, these unexpected experiences are often associated with distress especially due to a sense of paralysis. Indeed, although AAWR at the emergence has multiple causes, in the majority of cases the complication develops when the anesthesia plan is too early lightened at the end of anesthesia and there is a lack of use, or misuse, of neuromuscular monitoring with improper management of the neuromuscular block. Because the distress caused by the sense of paralysis represents an important predictor for the development of severe psychological complications, the knowledge of the phenomenon, and the possible strategies for its prophylaxis are aspects of considerable importance. Nevertheless, a limited percentage of episodes of AAWR cannot be prevented. This paradox holds also during the emergence phase of anesthesia which represents a very complex neurophysiological process with many aspects yet to be clarified.

Comparison of Propofol-Dexmedetomidine-Based Intravenous and Sevoflurane-Based Inhalational Anesthesia in Patients Undergoing Modified Radical Mastectomy.

BACKGROUND AND AIM: Total intravenous anesthesia (TIVA) has proven advantage over inhalational anesthesia in terms of stable hemodynamic, eco-friendly, and good recovery profile, but apprehension regarding adequate depth of anesthesia and intraoperative recall is still pertaining. This study aims to compare propofol-dexmedetomidine-based TIVA with sevoflurane-based inhalational anesthesia in modified radical mastectomy in terms of depth of anesthesia, intraoperative recall, recovery profile, and hemodynamic status. SETTINGS AND DESIGN: This prospective randomized controlled study was conducted at a tertiary care center over a time frame of 1 year. METHODOLOGY: In this randomized controlled study, 100 patients were randomly distributed into two groups: TIVA (Group T) and inhalational anesthesia (Group I). Group T patients received injection dexmedetomidine: 1 µg.kg-1 over 10 min followed by 0.7 µg.kg-1.h-1 and injection propofol: 25-100 µg.kg-1.min-1. Ventilation was maintained with oxygen-air gas flow. In Group I, patients were ventilated with nitrous oxide-oxygen (50:50) and sevoflurane. Rest of anesthesia for both the groups was same. Primary objective was to achieve adequate depth of anesthesia as monitored by intraoperative bispectral index value (BIS, 40-60). Hemodynamic variables, recovery profile, and amount of individual anesthetic agent consumed were recorded for comparison between two groups. For comparison of scale variables between two groups, independent sample t-test for significant difference between two sample means has been followed. RESULTS: Intraoperative BIS and hemodynamic variables were comparable (P > 0.05). Emergence time was 5.10 min in the TIVA group versus 8.38 min in the inhalational group (P = 0.00). Modified Aldrete score was comparable in two groups (P > 0.05). Cost of TIVA agents consumed per patient was 40% lesser than inhalational agents. CONCLUSION: TIVA maintains adequate depth of anesthesia along with stable hemodynamic and good recovery profile, at low cost in an eco-friendly manner.

MOTANA: study protocol to investigate motor cerebral activity during a propofol sedation.

BACKGROUND: Accidental Accidental awareness during general anesthesia (AAGA) occurs in 1-2% of high-risk practice patients and is a cause of severe psychological trauma, termed post-traumatic stress disorder (PTSD). However, no monitoring techniques can accurately predict or detect AAGA. Since the first reflex for a patient during AAGA is to move, a passive brain-computer interface (BCI) based on the detection of an intention of movement would be conceivable to alert the anesthetist. However, the way in which propofol (i.e., an anesthetic commonly used for the general anesthesia induction) affects motor brain activity within the electroencephalographic (EEG) signal has been poorly investigated and is not clearly understood. For this reason, a detailed study of the motor activity behavior with a step-wise increasing dose of propofol is required and would provide a proof of concept for such an innovative BCI. The main goal of this study is to highlight the occurrence of movement attempt patterns, mainly changes in oscillations called event-related desynchronization (ERD) and event-related synchronization (ERS), in the EEG signal over the motor cortex, in healthy subjects, without and under propofol sedation, during four different motor tasks. METHODS: MOTANA is an interventional, prospective, exploratory, physiological, monocentric, and randomized study conducted in healthy volunteers under light anesthesia, involving EEG measurements before and after target-controlled infusion of propofol at three different effect-site concentrations (0 µg.ml -1, 0.5 µg.ml -1, and 1.0 µg.ml -1). In this exploratory study, 30 healthy volunteers will perform 50 trials for the four motor tasks (real movement, motor imagery, motor imagery with median nerve stimulation, and median nerve stimulation alone) in a randomized sequence. In each conditions and for each trial, we will observe changes in terms of ERD and ERS according to the three propofol concentrations. Pre- and post-injection comparisons of propofol will be performed by paired series tests. DISCUSSION: MOTANA is an exploratory study aimed at designing an innovative BCI based on EEG-motor brain activity that would detect an attempt to move by a patient under anesthesia. This would be of interest in the prevention of AAGA. TRIAL REGISTRATION: Agence Nationale de Sécurité du Médicament (EUDRACT 2017-004198-1), NCT03362775. Registered on 29 August 2018. https://clinicaltrials.gov/ct2/show/NCT03362775?term=03362775&rank=1.

Median Nerve Stimulation Based BCI: A New Approach to Detect Intraoperative Awareness During General Anesthesia.

Hundreds of millions of general anesthesia are performed each year on patients all over the world. Among these patients, 0.1-0.2% are victims of Accidental Awareness during General Anesthesia (AAGA), i.e., an unexpected awakening during a surgical procedure under general anesthesia. Although anesthesiologists try to closely monitor patients using various techniques to prevent this terrifying phenomenon, there is currently no efficient solution to accurately detect its occurrence. We propose the conception of an innovative passive brain-computer interface (BCI) based on an intention of movement to prevent AAGA. Indeed, patients typically try to move to alert the medical staff during an AAGA, only to discover that they are unable to. First, we examine the challenges of such a BCI, i.e., the lack of a trigger to facilitate when to look for an intention to move, as well as the necessity for a high classification accuracy. Then, we present a solution that incorporates Median Nerve Stimulation (MNS). We investigate the specific modulations that MNS causes in the motor cortex and confirm that they can be altered by an intention of movement. Finally, we perform experiments on 16 healthy participants to assess whether an MI-based BCI using MNS is able to generate high classification accuracies. Our results show that MNS may provide a foundation for an innovative BCI that would allow the detection of AAGA.

Intraoperative awareness and experience with a ketamine-based anaesthesia package to support emergency and essential surgery when no anaesthetist is available.

INTRODUCTION: Five of the 7.2 billion people on earth have limited access to emergency and essential surgical procedures. The lack of safe, affordable and timely anaesthesia services are primary barriers to universal surgical coverage. The objective of this study was to assess intraoperative awareness when the 'Every Second Matters for Emergency and Essential Surgery - Ketamine' (ESM-Ketamine) package was used to support emergency and essential surgeries and painful procedures in rural Kenya when no anaesthetist was available. METHODS: Forty-seven consecutive adult patients that underwent an operative procedure under ESM-Ketamine at Sagam Community Hospital in Luanda, Kenya were enrolled. Participants underwent two semi-structured interviews that explored the patient's experience with ESM-Ketamine both after the operative procedure and four to six weeks after surgery. RESULTS: Forty-seven participants completed the first interview and 37 (78.7%) the second interview. Thirty-seven (78.7%) cases were procedural sedations and ten were (21.3%) emergency surgeries. Intraoperative awareness occurred in nine (24.3%) participants who underwent procedural sedation and two (20%) who underwent emergency surgery. Twenty-six (55.3%) participants reported dreams during the procedure. Thirty-two (86.5%) participants considered their experience positive, and 35 (95%) would recommend a procedure supported by ketamine to a friend. DISCUSSION: Most patients whose painful procedures and emergency operations were supported by the ESM-Ketamine package when no anaesthetist was available reported favourable experiences.

BIS Monitoring on Intraoperative Awareness: A Meta-analysis.

Intraoperative awareness is a very serious complication of general anesthesia. Several studies have evaluated the potential association between bispectral index (BIS) and intraoperative awareness, however, the results obtained were controversial. Therefore, we performed a meta-analysis to further assess the association between the BIS monitoring and the incidence of intraoperative awareness. A comprehensive search was conducted to identify all eligible studies from the online literature databases published prior to Feb. 2017. A total of five studies with 17 432 cases and 16 749 controls were included. An odds ratio (OR) and a 95% confidence interval (CI) were calculated to examine the strength of the association. The results showed that in the overall analysis, the association between the BIS monitoring and the incidence of intraoperative awareness was not significant (OR=0.58, 95% CI= 0.22-1.58, P=0.29). A stratified analysis by comparing different anesthesia methods revealed that BIS monitoring group showed a lower incidence of intraoperative awareness in patients with intravenous anesthesia when compared with non-BIS monitoring group (OR=0.20, 95% CI=0.08-0.49, P=0.0004), whereas there was no statistically significant difference in the incidence of intraoperative awareness between BIS and non-BIS monitoring groups in patients with inhalation anesthesia (OR=1.13, 95% CI=0.56-2.26, P=0.73). In conclusion, our meta-analysis showed that BIS monitoring had no appreciable advantage in the reduction of the intraoperative awareness incidence in inhalation anesthesia, while showed a remarkable superiority in intravenous anesthesia.

Frecuencia relativa de ocurrencia de casos probables de «despertar intraoperatorio¼ (DIO) en pacientes sometidos a anestesia general balanceada en el Hospital Central Militar / Relative frequency of occurrence of probable cases of intraoperative awareness (IA) in patients undergoing general balanced anaesthesia in the Central Military Hospital

Resumen Introducción El despertar intraoperatorio (DIO) es un fenómeno poco frecuente que afecta aproximadamente a 0.1-0.2% de los pacientes sometidos a anestesia general balanceada (AGB). Material y métodos Estudio de tipo observacional, descriptivo y transversal para detectar casos probables de DIO en sujetos que fueron sometidos a AGB en el Hospital Central Militar. El método estadístico fue la frecuencia relativa de ocurrencia. Resultados Se realizó con una muestra de 105 pacientes mediante la aplicación del cuestionario de Brice al paciente en la Unidad de Cuidados Postanestésicos en el postoperatorio inmediato y a las 24 horas tras su procedimiento quirúrgico. En un periodo de estudio de seis meses, se estudiaron 105 individuos que cumplieron con criterios de inclusión para el estudio, 51% (54/105) fueron mujeres y 49% (51/105) hombres. La intervención más común fue la colecistectomía laparoscópica (29%). A todos los individuos incluidos en el estudio (100%; 105/105) se les aplicó el cuestionario de Brice en el postoperatorio inmediato. Se detectaron tres casos probables de DIO, lo que representa el 2.8% del universo de estudio. Conclusiones El cuestionario de Brice fue una herramienta de fácil empleo, barata, viable y libre de impacto clínico organizacional negativo para detectar casos probables de DIO en la institución.

Abstract Introduction Intraoperative awareness (IA) is a rare phenomenon that affects approximately 0.1-0.2% of patients undergoing general anesthesia balanced (GBA). Material and methods Observational, descriptive and transversal study to detect probable cases of IA in subjects who were undergoing GBA in the Central Military Hospital. The statistical method used was the relative frequency of occurrence. Results We included a sample of 105 patients to whom we applied the questionnaire of Brice in the immediate postoperative period and 24 hours after their surgical procedure. In a six-month study period, were studied 105 individuals who met the inclusion criteria for the study, 51% (54/105) were female and 49% (51/105) men. Laparoscopic cholecystectomy (29%) was the most common intervention. We applied the questionnaire of Brice in the immediate postoperative period to all individuals included in the study (100%; 105/105). Three probable cases of IA were detected, representing 2.8% of the universe of study. Conclusions The questionnaire of Brice was a tool that was easy to use, inexpensive, viable, and free of negative clinical organizational impact to detect probable cases of IA in the institution.