Dreaming during gastrointestinal endoscopy under propofol, ciprofol, or remimazolam anesthesia: study protocol for a parallel-design double-blind, single-center trial.

BACKGROUND: Dreaming sometimes occurs during sedation. It has been reported that factors such as different anesthetics, depth of anesthesia, age, sex, and preoperative psychological state may affect dreams. Ciprofol and remimazolam are novel choices for painless endoscopy. Herein, we aimed to investigate dreaming during gastrointestinal endoscopy under propofol, ciprofol, and remimazolam anesthesia respectively. METHODS: This is a prospective, parallel-design double-blind, single-center clinical trial. Three hundred and sixty subjects undergoing elective painless gastroscopy, colonoscopy, or gastroenteroscopy will be enrolled. Eligible subjects will undergo propofol-, ciprofol-, or remimazolam-induced anesthesia to finish the examination. Interviews about the modified Brice questionnaire will be conducted in the recovery room. Incidence of dreaming is set as the primary outcome. Secondary outcomes include type of dreams, improvement of sleep quality, evaluation of patients, incidence of insufficient anesthesia, and intraoperative awareness. Safety outcomes are the incidences of hypotension and hypoxia during examination and adverse events during recovery. DISCUSSION: This study may observe different incidences of dreaming and diverse types of dreams, which might lead to different evaluations to the anesthesia procedure. Based on the coming results, anesthesiologists can make a better medication plan for patients who are going to undergo painless diagnosis and treatment. TRIAL REGISTRATION: This trial was registered at the Chinese Clinical Trial Registry on May 18, 2023 (registration number ChiCTR2300071565).

Awareness Under Anesthesia.

You begin to hear distant rock music playing, people conversing about their weekend. Then the scalpel is requested-incision. Pain sends you reeling and you attempt to muster a scream. No one seems to hear you and you are unable to lift a finger. The scenario is so rare that numerous movies have been made about awareness under anesthesia. Awareness under anesthesia is a rare event, however, it is a complication that no one ever desires to occur. We will explore how frequent awareness is during surgery, what risk factors are involved, and what tools anesthesia providers utilize to ensure everyone undergoing surgery is adequately anesthetized.

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.

Spectral edge frequency during general anaesthesia: A narrative literature review.

Previous studies have attempted to determine the depth of anaesthesia with different anaesthetic agents using electroencephalogram (EEG) measurements with variable success. Measuring depth of anaesthesia is confounded by the complexity of the EEG and the fact that different agents create different pattens. A narrative review was undertaken to examine the available research evidence on the effect and reliability of spectral edge frequency (SEF) for assessing the depth of anaesthesia in adult patients under general anaesthesia. A systematic search of the PubMed®, Scopus®, CINAHL and Cochrane databases identified six randomized controlled trials and five observational studies. The findings of these studies suggest that SEF varies according to the anaesthetic drugs used. Remifentanil and age are two factors that can affect SEF, while other opioids and benzodiazepine (administered separately) seem to have no effect. No patients experienced intraoperative awareness. However, this does not indicate that SEF can provide full protection against it and the number of articles in which intraoperative awareness was studied was too small to afford any certainty. None of the studies demonstrated a reliable SEF interval associated with adequate general anaesthesia. SEF must be adapted to the anaesthetic drug used, the patient's age and state while under general anaesthesia.

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.

Craneotomía en el paciente despierto / Awake craniotomy

Introducción: La craneotomía con el paciente despierto es útil para lograr resecciones cerebrales amplias de lesiones de áreas elocuentes. Objetivo: Presentar un caso al que se le realizó la técnica dormido- despierto. Método: Se realizó la inducción de la anestesia con propofol/fentanilo/rocuronio y se colocó una mascarilla laríngea. Después del bloqueo de escalpe se mantuvo la infusión de propofol/fentanilo y lidocaína hasta que se realizó la craneotomía. Se disminuyó la velocidad de infusión y se mantuvo de esta manera hasta finalizada la intervención. Resultados: Se logró el despertar del paciente a los 13 minutos de reducida la infusión. Se mantuvo buena estabilidad hemodinámica, sin depresión respiratoria ni otras complicaciones. El paciente se mantuvo colaborador, respondió preguntas y movilizó sus extremidades. No presentó complicaciones posoperatorias. Discusión: Dentro de las técnicas anestésicas utilizadas en el mundo la dormido- despierto-dormido es la más popular; sin embargo, constituye una alternativa no dormir nuevamente al paciente ni reinstrumentar la vía respiratoria. Los medicamentos más empleados son el propofol/remifentanilo, aunque la comparación con otros opioides no arrojan diferencias significativas; aunque sí supone un beneficio adicional la dexmedetomidina. Conclusiones: La craneotomía con el paciente despierto es posible de realizar en el entorno hospitalario siempre que exista un equipo multidisciplinario que consensue las mejores acciones médicas para el paciente(AU)

Introduction: Awake craniotomy is useful to achieve wide brain resections of lesions in eloquent areas. Objective: To present the case of a patient who was operated on with the asleep-awake-asleep technique. Method: Anesthesia was induced with propofol-fentanyl-rocuronium and a laryngeal mask was placed. After scalp block, the propofol-fentanyl and lidocaine infusion was maintained until craniotomy was performed. The infusion rate was decreased and remained this way until the end of the intervention. Results: The patient was awakened thirteen minutes after the infusion was reduced. Good hemodynamic stability was maintained, without respiratory depression or other complications. The patient remained collaborative, answered questions, and mobilized his limbs. He had no postoperative complications. Discussion: Among the anesthetic techniques used in the world, asleep-awake-asleep is the most popular. However, it is an alternative not to put the patient back to sleep or re-instrument the airway. The most commonly used drugs are propofol-remifentanil, although the comparison with other opioids does not show significant differences, except for dexmedetomidine, which does represent an additional benefit. Conclusions: Awake craniotomy is possible to be performed in the hospital setting as long as there is a multidisciplinary team that agrees on the best medical actions for the patient(AU)

Incidence of accidental awareness during general anaesthesia in obstetrics: a multicentre, prospective cohort study.

General anaesthesia for obstetric surgery has distinct characteristics that may contribute towards a higher risk of accidental awareness during general anaesthesia. The primary aim of this study was to investigate the incidence, experience and psychological implications of unintended conscious awareness during general anaesthesia in obstetric patients. From May 2017 to August 2018, 3115 consenting patients receiving general anaesthesia for obstetric surgery in 72 hospitals in England were recruited to the study. Patients received three repetitions of standardised questioning over 30 days, with responses indicating memories during general anaesthesia that were verified using interviews and record interrogation. A total of 12 patients had certain/probable or possible awareness, an incidence of 1 in 256 (95%CI 149-500) for all obstetric surgery. The incidence was 1 in 212 (95%CI 122-417) for caesarean section surgery. Distressing experiences were reported by seven (58.3%) patients, paralysis by five (41.7%) and paralysis with pain by two (16.7%). Accidental awareness occurred during induction and emergence in nine (75%) of the patients who reported awareness. Factors associated with accidental awareness during general anaesthesia were: high BMI (25-30 kg.m-2 ); low BMI (<18.5 kg.m-2 ); out-of-hours surgery; and use of ketamine or thiopental for induction. Standardised psychological impact scores at 30 days were significantly higher in awareness patients (median (IQR [range]) 15 (2.7-52.0 [2-56]) than in patients without awareness 3 (1-9 [0-64]), p = 0.010. Four patients had a provisional diagnosis of post-traumatic stress disorder. We conclude that direct postoperative questioning reveals high rates of accidental awareness during general anaesthesia for obstetric surgery, which has implications for anaesthetic practice, consent and follow-up.

Unintended intraoperative awareness: An analysis of Perioperative Anesthetic Adverse Events in Thailand (PAAd Thai).

BACKGROUND: Despite the improvement of anesthetic-related modalities, the incidence of unintended intraoperative awareness remains at around 0.005-0.038%. OBJECTIVE: We aimed to describe the intraoperative awareness incidents that occurred across Thailand between January to December, 2015. METHODS: Observational data was collected from 22 hospitals throughout Thailand. The awareness category was selected from incident reports according to the Perioperative Anesthetic Adverse Events in Thailand (PAAd Thai) study database and descriptive statistics were analyzed. The awareness characteristics and the related factors were recorded. RESULTS: A total of nine intraoperative awareness episodes from 2000 incidents were observed. The intraoperative awareness results were as follows: experience of pain (38.1%), perception of sound (33.3%), perception of intubation (9.5%) and feeling of paralysis (14.3%). The observed factors that affect intraoperative awareness were anesthesia-related (100%), patient-related (55.5%), surgery-related (22.2%) and systematic process-related (22.2%). The contributing factors were situational inexperience (77.8%) and inappropriate patient evaluation (44.4%). An awareness of anesthetic performer (100%) and experience (88.9%) were defined as incident-mitigating factors. The suggested corrective strategies were quality assurance activity (88.9%), improved supervision (44.4%) and equipment utilization (33.3%), respectively. CONCLUSION: Nine intraoperative awareness incidents were observed, however the causes were preventable. The anesthetic component seems to be the most influential to prevent these events.

Deep Learning Techniques to Improve Intraoperative Awareness Detection from Electroencephalographic Signals.

Every year, millions of patients regain conscious- ness during surgery and can potentially suffer from post-traumatic disorders. We recently showed that the detection of motor activity during a median nerve stimulation from electroencephalographic (EEG) signals could be used to alert the medical staff that a patient is waking up and trying to move under general anesthesia [1], [2]. In this work, we measure the accuracy and false positive rate in detecting motor imagery of several deep learning models (EEGNet, deep convolutional network and shallow convolutional network) directly trained on filtered EEG data. We compare them with efficient non-deep approaches, namely, a linear discriminant analysis based on common spatial patterns, the minimum distance to Riemannian mean algorithm applied to covariance matrices, a logistic regression based on a tangent space projection of covariance matrices (TS+LR). The EEGNet improves significantly the classification performance comparing to other classifiers (p- value <; 0.01); moreover it outperforms the best non-deep classifier (TS+LR) for 7.2% of accuracy. This approach promises to improve intraoperative awareness detection during general anesthesia.

Variability of anesthetic depth in total intravenous anesthesia vs balanced anesthesia using entropy indices: a randomized, crossover, controlled clinical trial / Variabilidad de la profundidad anestésica en anestesia total intravenosa vs. anestesia general balanceada usando índices de entropía. Un ensayo clínico aleatorizado, cruzado y controlado

Abstract Introduction: Total intravenous anesthesia (TIVA) and balanced anesthesia (BA) are the most commonly used anesthetic techniques. The differences are the variability of the depth of anesthesia between these techniques that might predict which one is safer for patients and presents a lower risk of intraoperative awakening. Objective: To determine whether a difference exists in the variability of depth of anesthesia obtained by response entropy (RE). Methods: A crossover clinical trial was conducted on 20 healthy patients receiving upper or lower limb ambulatory orthopedic surgery. Patients were randomly assigned to (a) target-controlled infusion of propofol using the Schnider model at a target concentration of 2.5 µg/mL for 15 minutes and a 10-minute washout, followed by sevoflurane administration at 0.8 minimal alveolar concentration (MAC) for the reminder of the surgery, or (b) the reverse sequence. Differences in the variability of the depth of anesthesia using RE were evaluated using paired t-test. Results: The treatment effect showed no significant difference in the average values of RE, during TIVA = 97.23 vs BA 97.04 (P = 0.39). Carry Over (-4.98 vs 4.08) and Period (100.3 vs 94.68) effects were not significantly different. Conclusion: The present study suggests that both anesthetic techniques are equivalent in terms of the stability of the depth of anesthesia. It is important to keep testing the determinants of the efficacy of different populations because the individual behaviors of patients might ultimately tip the scale.

Resumen Introducción: La anestesia total intravenosa (TIVA, por sus siglas en inglés) y la anestesia balanceada (AB) son las técnicas anestésicas más comúnmente utilizadas. La diferencia está en la variabilidad de la profundidad de la anestesia entre estas dos técnicas, lo cual pudiera predecir cuál es más segura para los pacientes y representar un menor riesgo de despertar intraoperatorio. Objetivo: Determinar si existe alguna diferencia en la variabilidad de la profundidad de la anestesia obtenida según los índices de entropía de respuesta (ER). Métodos: Se llevó a cabo un estudio clínico cruzado en 20 pacientes sanos que se sometieron a cirugía ortopédica ambulatoria de miembros superiores o inferiores. Los pacientes se asignaron aleatoriamente así: a) infusión controlada por objetivo (TCI, por sus siglas en inglés) de propofol, utilizando el modelo Schnider a una concentración objetivo de 2,5 µg/mL durante 15 min y un período de lavado de 10 minutos, seguido de la administración de sevoflurano a 0,8 de concentración alveolar mínima (CAM) durante el tiempo restante de la cirugía; o b) la secuencia inversa. Las diferencias en la variabilidad de la profundidad de la anestesia utilizando entropía de respuesta se evaluaron utilizando la prueba t pareada. Resultados: El efecto del tratamiento no mostró ninguna diferencia significativa en los valores promedio de entropía de respuesta (ER) durante TIVA = 97,23 vs. AB 97,04 (P = 0,39). Los efectos de arrastre (-4,98 vs. 4,08) y período (100,3 vs. 94,68) no fueron significativamente diferentes. Conclusiones: El presente estudio sugiere que ambas técnicas anestésicas son equivalentes en términos de estabilidad de la profundidad de la anestesia. Es importante continuar probando los factores determinantes de eficacia en las distintas poblaciones, ya que el comportamiento individual de cada paciente pudiera finalmente inclinar la balanza.

The relation between preoperative anxiety and awareness during anesthesia: an observational study / Relação entre ansiedade pré-operatória e consciência durante a anestesia: estudo observacional

Abstract Background: Anxiety is a state of worry caused by the anticipation of external or internal danger. Awareness During Anesthesia (ADA) is an unexpected memory recall during anesthesia. In this study, we aimed to determine the factors that affect preoperative anxiety and observe the incidence of ADA, as well as to determine the anxiety levels of these patients with a history of ADA. Methods: This study was planned to be prospective, observational, and cross-sectional. Patients in whom septoplasty was planned, who was admitted to the anesthesiology outpatients between March 2018 and September 2018, were ASA I-II, and aged 18-70 years were included in the study. The demographic characteristics of patients were recorded. The State-Trait Anxiety Inventory (STAI) was used to determine anxiety during a preoperative evaluation. The modified Brice awareness score was used simultaneously to determine previous ADA. Results: The anxiety scores of patients who were conscious during anesthesia were higher than other patients. The mean STAI score was 40.85 ± 14.8 in the 799 patients who met the inclusion criteria of this study. When the anxiety scores were compared, the scores were higher in females than in males (p < 0.05). The mean STAI score was found as 40.3 ± 13.8 in patients who dreamed during anesthesia. Conclusion: It is important to determine the anxiety levels of patients in the preoperative period to prevent the associated complications. Preoperative anxiety, besides preventing ADA, should be dealt with in a multidisciplinary manner. ADA should be carefully questioned while evaluating previous anesthesia experiences.

Resumo Justificativa: A ansiedade é um estado de preocupação causado pela expectativa de perigo externo ou interno. Consciência durante a anestesia (CDA) é a evocação imprevista da memória de eventos intranestésicos. O objetivo deste estudo foi determinar os fatores que afetam a ansiedade pré-operatória, a incidência de CDA e os níveis de ansiedade nos pacientes com antecedente de CDA. Método: O estudo foi planificado como prospectivo, observacional e transversal. Foram incluídos no estudo pacientes programados para septoplastia eletiva, admitidos ao ambulatório de anestesiologia entre Março de 2018 e Setembro de 2018, com classe funcional ASA I-II e faixa etária entre 18 e 70 anos. As características demográficas dos pacientes foram registradas. O Inventário de Ansiedade Traço-Estado (IDATE) foi utilizado para determinar a ansiedade durante a avaliação pré-operatória. Simultaneamente, o escore de consciência de Brice modificado foi usado para determinar CDA anterior. Resultados: Os escores de ansiedade dos pacientes que apresentaram CDA foram mais elevados do que de outros pacientes. A pontuação média do IDATE foi 40,85±14,8 nos 799 pacientes que obedeceram aos critérios de inclusão do estudo. Quando os escores de ansiedade foram comparados, foram maiores no sexo feminino do que no masculino (p < 0,05). O escore médio do IDATE encontrado foi 40,3±13,8 nos pacientes que relataram sonhos durante a anestesia. Conclusão: É importante determinar no pré-operatório os níveis de ansiedade dos pacientes para evitar as complicações associadas. Ansiedade pré-operatória e a prevenção de CDA devem ser tratadas com abordagem multiprofissional. A CDA deve ser cuidadosamente investigada, avaliando-se as experiências vividas pelo paciente em anestesias pregressas.

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.

Protocol for direct reporting of awareness in maternity patients (DREAMY): a prospective, multicentre cohort study of accidental awareness during general anaesthesia.

BACKGROUND: Accidental awareness during general anaesthesia (AAGA) is a complex and rare outcome to investigate in surgical patient populations, particularly obstetric patients. We report the protocol of the Direct Reporting of Awareness in Maternity patients (DREAMY) study, illustrating how the research was designed to address practical and methodological challenges for investigating AAGA in an obstetric cohort. METHODS: This is the trial protocol of a prospective, multicentre cohort study of patients undergoing obstetric surgery under general anaesthesia. Accidental awareness during general anaesthesia will be detected using three repetitions of standardised direct questioning over 30 days, with responses indicating memories during general anaesthesia verified using structured interviews. Reports will be adjudicated, then classified, in accordance with pre-defined and pre-validated structures, including the Michigan Awareness Classification tool. Quantitative data will be collected on general anaesthesia conduct for all participants. This descriptive study is being conducted in England and aims to recruit a minimum of 2015 patients. RESULTS: The DREAMY study was prospectively registered (ClinicalTrials.gov Identifier: NCT03100396) and ethical approval granted. Participant recruitment began in May 2017 and one year follow up concluded in August 2019. Publication of the results is anticipated in 2020. CONCLUSIONS: The DREAMY study will provide data on incidence, experience and implications of AAGA for obstetric patients, using a robust methodology that will reliably detect and translate subjective AAGA reports into objective outcomes. In addition, the study is expected to improve vigilance for AAGA in participating hospitals and encourage adoption of recommendations for support of patients experiencing AAGA.

A narrative review of electroencephalogram-based monitoring during cardiovascular surgery.

PURPOSE OF REVIEW: The current narrative review focuses on depth of hypnosis monitoring with electroencephalography (EEG) during cardiovascular surgery. There have been important findings in recent years regarding the challenges and limitations of EEG-based monitoring during general anesthesia. The purpose of this review is to summarize key EEG-related concepts, as well as to highlight some of the advantages and disadvantages of processed and unprocessed EEG monitoring, especially for older patients with comorbidities undergoing cardiovascular surgery. RECENT FINDINGS: The brain is the target organ of anesthesia. Using the EEG or processed EEG to guide anesthetic administration during cardiovascular surgery conceptually allows precision patient-centered anesthesia. It is suggested that inadequate anesthesia, with the possibility of traumatic intraoperative awareness, can potentially be avoided. Furthermore, excessive anesthesia, with hemodynamic compromise and theoretical risk of delirium, can be minimized. Frail, older patients undergoing major surgery with preexisting neurocognitive disorders might be especially vulnerable to perioperative neurological and other complications. Tailoring anesthetic administration, based on individual patient needs partly guided by certain EEG features, might yield improved perioperative outcomes. SUMMARY: Ability to interpret the EEG during surgery might help anesthesia clinicians to individualize anesthetic administration to prevent adverse events, and optimize postoperative recovery.

Bispectral index for improving intraoperative awareness and early postoperative recovery in adults.

BACKGROUND: The use of clinical signs, or end-tidal anaesthetic gas (ETAG), may not be reliable in measuring the hypnotic component of anaesthesia and may lead to either overdosage or underdosage resulting in adverse effects because of too deep or too light anaesthesia. Intraoperative awareness, whilst uncommon, may lead to serious psychological disturbance, and alternative methods to monitor the depth of anaesthesia may reduce the incidence of serious events. Bispectral index (BIS) is a numerical scale based on electrical activity in the brain. Using a BIS monitor to guide the dose of anaesthetic may have advantages over clinical signs or ETAG. This is an update of a review last published in 2014. OBJECTIVES: To assess the effectiveness of BIS to reduce the risk of intraoperative awareness and early recovery times from general anaesthesia in adults undergoing surgery. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, and Web of Science on 26 March 2019. We searched clinical trial registers and grey literature, and handsearched reference lists of included studies and related reviews. SELECTION CRITERIA: We included randomized controlled trials (RCTs) and quasi-RCTs in which BIS was used to guide anaesthesia compared with standard practice which was either clinical signs or end-tidal anaesthetic gas (ETAG) to guide the anaesthetic dose. We included adult participants undergoing any type of surgery under general anaesthesia regardless of whether included participants had a high risk of intraoperative awareness. We included only studies in which investigators aimed to evaluate the effectiveness of BIS for its role in monitoring intraoperative depth of anaesthesia or potential improvements in early recovery times from anaesthesia. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed studies for inclusion, extracted data, and assessed risk of bias. We assessed the certainty of evidence with GRADE. MAIN RESULTS: We included 52 studies with 41,331 participants; two studies were quasi-randomized and the remaining studies were RCTs. All studies included participants undergoing surgery under general anaesthesia. Three studies recruited only participants who were at high risk of intraoperative awareness, whilst two studies specifically recruited an unselected participant group. We analysed the data according to two comparison groups: BIS versus clinical signs; and BIS versus ETAG. Forty-eight studies used clinical signs as a comparison method, which included titration of anaesthesia according to criteria such as blood pressure or heart rate and, six studies used ETAG to guide anaesthesia. Whilst BIS target values differed between studies, all were within a range of values between 40 to 60.BIS versus clinical signsWe found low-certainty evidence that BIS-guided anaesthesia may reduce the risk of intraoperative awareness in a surgical population that were unselected or at high risk of awareness (Peto odds ratio (OR) 0.36, 95% CI 0.21 to 0.60; I2 = 61%; 27 studies; 9765 participants). However, events were rare with only five of 27 studies with reported incidences; we found that incidences of intraoperative awareness when BIS was used were three per 1000 (95% CI 2 to 6 per 1000) compared to nine per 1000 when anaesthesia was guided by clinical signs. Of the five studies with event data, one included participants at high risk of awareness and one included unselected participants, four used a structured questionnaire for assessment, and two used an adjudication process to identify confirmed or definite awareness.Early recovery times were also improved when BIS was used. We found low-certainty evidence that BIS may reduce the time to eye opening by mean difference (MD) 1.78 minutes (95% CI -2.53 to -1.03 minutes; 22 studies; 1494 participants), the time to orientation by MD 3.18 minutes (95% CI -4.03 to -2.33 minutes; 6 studies; 273 participants), and the time to discharge from the postanaesthesia care unit (PACU) by MD 6.86 minutes (95% CI -11.72 to -2 minutes; 13 studies; 930 participants).BIS versus ETAGAgain, events of intraoperative awareness were extremely rare, and we found no evidence of a difference in incidences of intraoperative awareness according to whether anaesthesia was guided by BIS or by ETAG in a surgical population at unselected or at high risk of awareness (Peto OR 1.13, 95% CI 0.56 to 2.26; I2 = 37%; 5 studies; 26,572 participants; low-certainty evidence). Incidences of intraoperative awareness were one per 1000 in both groups. Only three of five studies reported events, two included participants at high risk of awareness and one included unselected participants, all used a structured questionnaire for assessment and an adjudication process to identify confirmed or definite awareness.One large study (9376 participants) reported a reduced time to discharge from the PACU by a median of three minutes less, and we judged the certainty of this evidence to be low. No studies measured or reported the time to eye opening and the time to orientation.Certainty of the evidenceWe used GRADE to downgrade the evidence for all outcomes to low certainty. The incidence of intraoperative awareness is so infrequent such that, despite the inclusion of some large multi-centre studies in analyses, we believed that the effect estimates were imprecise. In addition, analyses included studies that we judged to have limitations owing to some assessments of high or unclear bias and in all studies, it was not possible to blind anaesthetists to the different methods of monitoring depth of anaesthesia.Studies often did not report a clear definition of intraoperative awareness. Time points of measurement differed, and methods used to identify intraoperative awareness also differed and we expected that some assessment tools were more comprehensive than others. AUTHORS' CONCLUSIONS: Intraoperative awareness is infrequent and, despite identifying a large number of eligible studies, evidence for the effectiveness of using BIS to guide anaesthetic depth is imprecise. We found that BIS-guided anaesthesia compared to clinical signs may reduce the risk of intraoperative awareness and improve early recovery times in people undergoing surgery under general anaesthesia but we found no evidence of a difference between BIS-guided anaesthesia and ETAG-guided anaesthesia. We found six studies awaiting classification and two ongoing studies; inclusion of these studies in future updates may increase the certainty of the evidence.

Intraoperative Awareness With Recall: A Descriptive, Survey-Based, Cohort Study.

BACKGROUND: Unintended intraoperative awareness with recall (AWR) is a potential complication of general anesthesia. Patients typically report recollections of (1) hearing sounds or conversations, (2) being unable to breathe or move, (3), feeling pain, and/or (4) experiencing emotional distress. The purpose of the current study was to identify and further characterize AWR experiences identified through postoperative surveys of a large unselected adult surgical cohort. METHODS: This is a substudy of a prospective registry study, which surveys patients on their health and well-being after surgery. Responses to 4 questions focusing on AWR were analyzed. Patients who reported AWR with pain, paralysis, and/or distress were contacted by telephone to obtain more information about their AWR experience. The interview results for patients who received general anesthesia were sent to 3 anesthesiologists, who adjudicated the reported AWR episodes. RESULTS: Of 48,151 surveys sent, 17,875 patient responses were received. Of these respondents, 622 reported a specific memory from the period between going to sleep and waking up from perceived general anesthesia and 282 of these reported related pain, paralysis, and/or distress. An attempt was made to contact these 282 patients, and 149 participated in a telephone survey. Among the 149 participants, 87 endorsed their prior report of AWR. However, only 22 of these patients had received general anesthesia, while 51 received only sedation and 14 received regional anesthesia. Three anesthesiologists independently adjudicated the survey results of the 22 general anesthesia cases and assigned 6 as definite AWR, 8 as possible AWR, and 8 as not AWR episodes. Of the 65 patients who confirmed their report of AWR after regional or sedation anesthesia, 37 (31 with sedation and 6 with regional anesthesia) had not expected to be conscious during surgery. CONCLUSIONS: The complication of AWR continues to occur during intended general anesthesia. Many reports of AWR episodes occur in patients receiving sedation or regional anesthesia and relate to incorrect expectations regarding anesthetic techniques and conscious experiences, representing a potential target for intervention.

Monitorización automática de estados de sedación en señales electroencefalográficas / Automatic monitoring of sedation states in electroencephalographic signals

La anestesia general proporciona al paciente estados de inconciencia, amnesia y analgesia, sin embargo, se reportan casos de despertar intraoperatorio. Debido a la incidencia de este fenómeno y sus efectos psicosomáticos, el Centro de Estudios de Neurociencias, Procesamiento de Imágenes y Señales en la Universidad de Oriente, y el Hospital General Juan Bruno Zayas Alfonso ambos en Santiago de Cuba, Cuba, implementan una metodología que permita detectar automáticamente estados de sedación anestésica aplicando Inteligencia Artificial. Para esto se emplearon las señales registradas por el canal electroencefalográfico F4, nueve parámetros espectrales, las Máquinas de Soporte Vectorial y los Sistemas Neuro-Difusos. En el reconocimiento automático de los estados de Sedación Profunda, Moderada y Ligera se logró una Exactitud de 96.12 por ciento, 90.06 por ciento y 90.24 por ciento respectivamente con las Máquinas de Soporte Vectorial, por lo que se propone el uso del canal electroencefalográfico F4 en la detección de estados anestésicos(AU)

General anesthesia provide the patient states of unconsciousness, amnesia and analgesia, however, cases of intraoperative awareness are reported. Due to the incidence of this phenomenon and the psychosomatic effects it causes, the Neuroscience Studies Center, Images and Signals Processing at the University of Oriente, and the General Hospital Juan Bruno Zayas Alfonso both in Santiago de Cuba, Cuba, implement a methodology that allows the automatic detection of anesthetic sedation states applying Artificial Intelligence. For this, the signals recorded by the electroencephalographic channel F4, nine spectral parameters, the Support Vector Machines and the Neuro-Fuzzy Systems were used. In the automatic recognition of the Sedation States: Profound, Moderate and Mild an Accuracy of 96.12 percent, 90.06 percent and 90.24 percent respectively was achieved with the Support Vector Machines, so the use of the electroencephalographic channel F4 is proposed in the detection of anesthetic states(AU)

Equipment failure of intravenous syringe pump detected by increase in Narcotrend stage: A case report.

RATIONALE: Awareness is the recovery of consciousness during general anesthesia. It occurs when patients under general anesthesia receive inadequate anesthetic medications to maintain unconsciousness during surgery. Equipment failure is a common cause of intraoperative awareness. PATIENT CONCERNS: A 16-year-old boy, 85 kg in weight, was admitted to our hospital for thyroglossal cystectomy under general anesthesia. Six minutes after the intubation, we noted that the Narcotrend index indicated a condition of light anesthesia and the patient was observed to be in tears. DIAGNOSIS: Improper positioning of the syringe fixing clamp on the CP700TCI infusion pump caused equipment failure and light anesthesia. INTERVENTIONS: Bolus of 50 mg propofol and 2 mg midazolam were administered manually by syringe, and inhalation of 2% sevoflurane was supplemented. Infusion pump was replaced. OUTCOMES: The Narcotrend index of the patient returned to state of deep anesthesia following manual administration of the anesthetic medications. Following the surgery, the patient had an uneventful recovery, and did not present with evidence of awareness. LESSONS: Users of the CP700TCI syringe pump should pay attention to the position of the syringe fixing clamp. Anesthesiologists should check all the equipment according to a defined checklist prior to anesthesia. Narcotrend monitor could help to detect light anesthesia and prevent potential awareness.

[Prevention of bleeding during laparotomic myomectomy in Sub-Saharan Africa: Contribution to the tourniquet on the uterine isthmus]. / Prévention de l'hémorragie per myomectomie en Afrique subsaharienne : apport du garrot sur l'isthme utérin.

OBJECTIVES: To appreciate the decrease of bleeding by myomectomy by the use of a tourniquet on the uterine isthmus. METHODS: We conducted a case-control retrospective study from March 2014 to February 2016 in the Gynecology and obstetrics Department of the university hospital of Yopougon (Abidjan, Ivory Coast). It interested 100 patients of which 50 had a myomectomy with the tourniquet on the uterine isthmus and 50 without the tourniquet. None of the patients received pre-operative preventive treatment. The criteria for comparison were the blood loss per operative and the pre-and post-operative hemoglobin levels. RESULTS: The average age of patients was 33 years. Nulliparous women were the group most affected (68% of our patients) with 32% infertile women in the group with the tourniquet and 18% in the group without the tourniquet. Patients without tourniquet presented more bleeding than patients with tourniquet (X2=13.61) with a higher proportion of anemic patients in the group without the tourniquet. The differences were significant. The tourniquet has made it possible to realize the resection of a larger number of myoma. The duration of hospital stay was 4 days on average in both groups and no complications were observed. CONCLUSIONS: The application of a tourniquet on the uterine isthmus during laparotomic myomectomy has a benefit in reducing intraoperative blood loss.