RESUMEN
BACKGROUND: The primary objective of anesthesiologists during the induction of anaesthesia is to mitigate the operative stress response resulting from endotracheal intubation. In this prospective, randomized controlled trial, our aim was to assess the feasibility and efficacy of employing Index of Consciousness (IoC, IoC1 and IoC2) monitoring in predicting and mitigating circulatory stress induced by endotracheal intubation for laparoscopic cholecystectomy patients under general anesthesia (GA). METHODS: We enrolled one hundred and twenty patients scheduled for laparoscopic cholecystectomy under GA and randomly allocated them to two groups: IoC monitoring guidance (Group T, n = 60) and bispectral index (BIS) monitoring guidance (Group C, n = 60). The primary endpoints included the heart rate (HR) and mean arterial pressure (MAP) of the patients, as well as the rate of change (ROC) at specific time points during the endotracheal intubation period. Secondary outcomes encompassed the systemic vascular resistance index (SVRI), cardiac output index (CI), stroke volume index (SVI), ROC at specific time points, the incidence of adverse events (AEs), and the induction dosage of remifentanil and propofol during the endotracheal intubation period in both groups. RESULTS: The mean (SD) HR at 1 min after intubation under IoC monitoring guidance was significantly lower than that under BIS monitoring guidance (76 (16) beats/min vs. 82 (16) beats/min, P = 0.049, respectively). Similarly, the mean (SD) MAP at 1 min after intubation under IoC monitoring guidance was lower than that under BIS monitoring guidance (90 (20) mmHg vs. 98 (19) mmHg, P = 0.031, respectively). At each time point from 1 to 5 min after intubation, the number of cases with HR ROC of less than 10% in Group T was significantly higher than in Group C (P < 0.05). Furthermore, between 1 and 3 min and at 5 min post-intubation, the number of cases with HR ROC between 20 to 30% or 40% in Group T was significantly lower than that in Group C (P < 0.05). At 1 min post-intubation, the number of cases with MAP ROC of less than 10% in Group T was significantly higher than that in Group C (P < 0.05), and the number of cases with MAP ROC between 10 to 20% in Group T was significantly lower than that in Group C (P < 0.01). Patients in Group T exhibited superior hemodynamic stability during the peri-endotracheal intubation period compared to those in Group C. There were no significant differences in the frequencies of AEs between the two groups (P > 0.05). CONCLUSION: This promising monitoring technique has the potential to predict the circulatory stress response, thereby reducing the incidence of adverse reactions during the peri-endotracheal intubation period. This technology holds promise for optimizing anesthesia management. TRAIL REGISTRATION: Chinese Clinical Trail Registry Identifier: ChiCTR2300070237 (20/04/2022).
Asunto(s)
Anestesia General , Monitores de Conciencia , Frecuencia Cardíaca , Intubación Intratraqueal , Monitoreo Intraoperatorio , Humanos , Anestesia General/métodos , Intubación Intratraqueal/métodos , Masculino , Femenino , Estudios Prospectivos , Persona de Mediana Edad , Adulto , Monitoreo Intraoperatorio/métodos , Frecuencia Cardíaca/fisiología , Colecistectomía Laparoscópica/métodos , Estado de Conciencia/efectos de los fármacos , Estrés Fisiológico , Presión Arterial , Propofol/administración & dosificaciónRESUMEN
Introduction: This study investigates the application of bispectral index (BIS) monitoring in rigid bronchoscopy to enhance anesthetic delivery and patient outcomes, a topic that remains underexplored. Materials and Methods: A retrospective analysis of 155 patients undergoing elective rigid bronchoscopy under general anesthesia was conducted. Patients were divided into BIS-monitored and conventional anesthesia groups. Inclusion criteria were adults aged over 18 years with American Society of Anesthesiologists (ASA) physical status I-IV. Result: No significant demographic differences were found between the groups. The BIS group showed significant reductions in propofol usage (231.40 ± 74.63 mg vs. 190.19 ± 91.83 mg, p= 0.003) and prednol dosage (94.27 ± 42.56 mg vs. 79.71 ± 18.97 mg, p= 0.020). Remifentanil administration approached statistical significance (56.99 ± 34.69 mcg vs. 45.36 ± 36.75 mcg, p= 0.055). Conclusions: No significant demographic differences were found between the groups. The BIS group showed significant reductions in propofol usage (231.40 ± 74.63 mg vs. 190.19 ± 91.83 mg, p= 0.003) and prednol dosage (94.27 ± 42.56 mg vs. 79.71 ± 18.97 mg, p= 0.020). Remifentanil administration approached statistical significance (56.99 ± 34.69 mcg vs. 45.36 ± 36.75 mcg, p= 0.055).
Asunto(s)
Anestesia General , Broncoscopía , Propofol , Remifentanilo , Humanos , Masculino , Femenino , Broncoscopía/métodos , Estudios Retrospectivos , Persona de Mediana Edad , Propofol/administración & dosificación , Remifentanilo/administración & dosificación , Anestesia General/métodos , Adulto , Monitores de Conciencia , Anciano , Anestésicos Intravenosos/administración & dosificación , Monitoreo Intraoperatorio/métodosRESUMEN
STUDY OBJECTIVE: The effect of volatile anesthetics on postoperative recovery in older adults is still not entirely clear. Thus, we evaluated the effect of desflurane versus sevoflurane anesthesia on speed of postoperative recovery in older adults eligible for same-day discharge. We further evaluated the incidence of postoperative nausea and vomiting (PONV), bispectral index (BIS) values, and S100B concentrations. DESIGN: Single-center, prospective, observer-blinded, randomized clinical trial. SETTING: Operating room. PATIENTS: 190 patients ≥65 years of age and scheduled for minor- to moderate-risk noncardiac surgeries. INTERVENTIONS: Goal-directed administration of desflurane versus sevoflurane for maintenance of anesthesia with an intraoperative goal of BIS 50 ± 5. MEASUREMENTS: The primary outcome was the time to anesthesia recovery, which was defined as the time between arrival at the post-anesthesia care unit (PACU) and reaching criteria for discharge from PACU, based on modified Aldrete score ≥ 12 points. Modified Aldrete scores were assessed at PACU arrival and thereafter in five-minute intervals. PONV was evaluated during PACU stay and the first three postoperative days, BIS values were recorded during PACU stay, and S100B values were measured before and after surgery, and on the second postoperative day. MAIN RESULTS: 95 patients were randomized to receive desflurane, and 95 patients to receive sevoflurane. We did not observe a significant difference in median duration of postoperative recovery between the groups (desflurane: 0 min [0;0]; sevoflurane: 0 min [0;0]; p = 0.245). 77 patients (81.1%) in the desflurane group and 84 patients (88.4%) in the sevoflurane group already had Aldrete scores ≥12 points upon arrival at PACU (p = 0.277). There was also no significant difference in the incidences of PONV (p = 0.606), postoperative BIS values (p = 0.197), and postoperative maximum S100B concentrations (p = 0.821) between the groups. CONCLUSIONS: Despite previous reports, we did not observe significant faster recovery times after desflurane anesthesia. Both volatile anesthetics may be appropriate for same-day discharge in older adults.
Asunto(s)
Periodo de Recuperación de la Anestesia , Anestésicos por Inhalación , Desflurano , Náusea y Vómito Posoperatorios , Subunidad beta de la Proteína de Unión al Calcio S100 , Sevoflurano , Humanos , Sevoflurano/administración & dosificación , Sevoflurano/efectos adversos , Desflurano/administración & dosificación , Desflurano/efectos adversos , Anestésicos por Inhalación/administración & dosificación , Anestésicos por Inhalación/efectos adversos , Anciano , Masculino , Estudios Prospectivos , Femenino , Náusea y Vómito Posoperatorios/epidemiología , Náusea y Vómito Posoperatorios/prevención & control , Subunidad beta de la Proteína de Unión al Calcio S100/sangre , Método Simple Ciego , Monitores de Conciencia , Éteres Metílicos/administración & dosificación , Éteres Metílicos/efectos adversosRESUMEN
STUDY OBJECTIVE: There is scarce evidence on the hemodynamic stability of remimazolam during anesthetic induction in patients with significant coronary artery disease. This study aims to compare the effects of remimazolam and propofol on post-induction hypotension in patients undergoing coronary artery bypass grafting (CABG). DESIGN: Randomized controlled trial. SETTING: Tertiary teaching hospital. PATIENTS: Adult patients undergoing isolated CABG. INTERVENTIONS: Patients were randomly allocated to received either remimazolam (n = 50) or propofol (n = 50) for anesthetic induction. The remimazolam group received an initial infusion at 6 mg/kg/h, which was later adjusted to 1-2 mg/kg/h to maintain a bispectral index of 40-60 after loss of consciousness. In the propofol group, a 1.5 mg/kg bolus of propofol was administered, followed by 1-1.5% sevoflurane inhalation as needed to achieve the target bispectral index. MEASUREMENTS: The primary outcome was the area under the curve (AUC) below the baseline mean arterial pressure (MAP) during the first 10 min after anesthetic induction. Secondary outcomes included the AUC for MAP <65 mmHg and the requirement for vasopressors. MAIN RESULTS: The remimazolam group demonstrated a significantly lower AUC under the baseline MAP compared to the propofol group (mean [SD], 169.8 [101.0] mmHg·min vs. 220.6 [102.4] mmHg·min; mean difference [95% confidence interval], 50.8 [10.4-91.2] mmHg·min; P = 0.014). Additionally, the remimazolam group had a reduced AUC for MAP <65 mmHg (7.3 [10.3] mmHg·min vs. 13.9 [14.9] mmHg·min; P = 0.007) and a lower frequency of vasopressor use compared to the propofol group (60% vs. 88%, P = 0.001). CONCLUSIONS: Remimazolam may offer improved hemodynamic stability during anesthetic induction in patients undergoing CABG, suggesting its potential advantage over propofol for patients with significant coronary artery disease in terms of hemodynamic stability.
Asunto(s)
Anestésicos Intravenosos , Puente de Arteria Coronaria , Hipotensión , Propofol , Humanos , Propofol/administración & dosificación , Propofol/efectos adversos , Masculino , Femenino , Puente de Arteria Coronaria/efectos adversos , Hipotensión/prevención & control , Persona de Mediana Edad , Anciano , Anestésicos Intravenosos/administración & dosificación , Anestésicos Intravenosos/efectos adversos , Benzodiazepinas/administración & dosificación , Benzodiazepinas/efectos adversos , Sevoflurano/administración & dosificación , Sevoflurano/efectos adversos , Presión Arterial/efectos de los fármacos , Monitores de Conciencia , Enfermedad de la Arteria Coronaria/cirugíaRESUMEN
BACKGROUND: Tracheostomy ventilation in motor neurone disease is an uncommon life-sustaining treatment. Best practice is having a plan for ventilation withdrawal, but the literature to guide practice is limited. Case reports have documented standard doses of opioids and benzodiazepines used for sedation in such cases. CASE: A 49-year-old man was diagnosed with motor neurone disease in 2016. He commenced tracheostomy ventilation in 2018. In 2022 and 2023, planning was undertaken, at the patient's request, for withdrawal of tracheostomy ventilation at home, when he was no longer able to communicate with technology. CASE PLANNING: Planning included Bispectral Index monitoring prior to cessation of ventilation, ensuring this only occurred when deep sedation was achieved. After ventilation withdrawal in 2023, a retrospective review of medications given and his level of sedation on monitoring was undertaken, with family consent. OUTCOME: Ventilation withdrawal was initiated after deep sedation was achieved, 6 h after commencing subcutaneous infusions of morphine, midazolam, clonazepam and phenobarbital. LESSONS: Doses required to achieve acceptable sedation exceeded literature reports. Achieving deep sedation was a longer than expected process. CONCLUSION: More research using an objective measure of sedation is required, as clinical assessment of sedation in this context is compromised.
Asunto(s)
Cuidados Paliativos , Traqueostomía , Humanos , Masculino , Persona de Mediana Edad , Sedación Profunda , Hipnóticos y Sedantes/administración & dosificación , Hipnóticos y Sedantes/uso terapéutico , Respiración Artificial , Enfermedad de la Neurona Motora/terapia , Monitores de Conciencia , Privación de TratamientoRESUMEN
Incorrect bispectral index (BIS) values have been reported due to interference with this monitoring system. We report a case of a 46-year-old woman who underwent liposuction and breast lipofilling, where we observed a misinterpretation by the BIS algorithm that has not yet been reported. Concurrently with abdominal and thigh liposuction, an increase in the BIS value was observed. The importance of examining electroencephalogram (EEG) and density spectral array (DSA) readings during liposuction procedures is highlighted in this case report, extending our observations beyond just the numerical BIS value, which is not always reliable.
Asunto(s)
Electroencefalografía , Lipectomía , Humanos , Femenino , Persona de Mediana Edad , Monitores de Conciencia , Monitoreo Intraoperatorio/métodosRESUMEN
Aging leads to anatomic and physiologic changes in the brain, making it more sensitive to the depressant effects of anesthetic medications and increasing the risk of postoperative neurocognitive complications such as postoperative delirium and postoperative cognitive dysfunction. This article explores the implications of anesthesia on elderly patients' brain health, emphasizing the heightened risk of postoperative neurocognitive disorders, and describes the BIS™ Monitoring System as a neuromonitoring tool for anesthesia professionals to assess the depth of anesthesia. The integration of the BIS Monitoring System into clinical practice can contribute to a more tailored and patient-centered approach to anesthesia management, ultimately improving perioperative outcomes and safety.
Asunto(s)
Enfermeras Anestesistas , Humanos , Anciano , Anciano de 80 o más Años , Anestesia , Monitoreo Intraoperatorio , Monitores de ConcienciaRESUMEN
Anaesthesia, crucial to surgical practice, is undergoing renewed scrutiny due to the integration of artificial intelligence in its medical use. The precise control over the temporary loss of consciousness is vital to ensure safe, pain-free procedures. Traditional methods of depth of anaesthesia (DoA) assessment, reliant on physical characteristics, have proven inconsistent due to individual variations. In response, electroencephalography (EEG) techniques have emerged, with indices such as the Bispectral Index offering quantifiable assessments. This literature review explores the current scope and frontier of DoA research, emphasising methods utilising EEG signals for effective clinical monitoring. This review offers a critical synthesis of recent advances, specifically focusing on electroencephalography (EEG) techniques and their role in enhancing clinical monitoring. By examining 117 high-impact papers, the review delves into the nuances of feature extraction, model building, and algorithm design in EEG-based DoA analysis. Comparative assessments of these studies highlight their methodological approaches and performance, including clinical correlations with established indices like the Bispectral Index. The review identifies knowledge gaps, particularly the need for improved collaboration for data access, which is essential for developing superior machine learning models and real-time predictive algorithms for patient management. It also calls for refined model evaluation processes to ensure robustness across diverse patient demographics and anaesthetic agents. The review underscores the potential of technological advancements to enhance precision, safety, and patient outcomes in anaesthesia, paving the way for a new standard in anaesthetic care. The findings of this review contribute to the ongoing discourse on the application of EEG in anaesthesia, providing insights into the potential for technological advancement in this critical area of medical practice.
Asunto(s)
Anestesia , Electroencefalografía , Aprendizaje Automático , Humanos , Electroencefalografía/métodos , Anestesia/métodos , Procesamiento de Señales Asistido por Computador , Monitores de Conciencia , AlgoritmosRESUMEN
AIM: To investigate the clinical nursing effect of bispectral index (BIS) monitoring for paroxysmal sympathetic hyperactivity (PSH) patients in the neurosurgical intensive care unit (NICU). METHODS: From January 2022 to June 2023, a total of 30 patients with PSH secondary to moderate to severe craniocerebral injury in the NICU were monitored for BIS. The patients' paroxysmal sympathetic hyperactivity-assessment measure (PSH-AM) scores were recorded. PSH patients generally appear in 3 states: calm state, seizure state, and postmedication state. Thirty PSH patients' BIS values were recorded during the calm period, during the seizure state, and postmedication state, and these 3 different stages' BIS values were divided into groups A, B, and C, using the Kruskal-Wallis H test to compare groups. RESULTS: The Kruskal-Wallis H test yielded a value of H=22.599, P <0.001. H0 was rejected against the test standard of α=0.05, and the BIS values of groups A, B, and C differed. The BIS values of group A and group B differed after a pairwise comparison, and the difference was statistically significant (adjusted P =0.001). Group B and group C had different BIS values, and the difference was statistically significant (adjusted P =0.001); group A and Group C had no difference in BIS values, and the difference was not statistically significant (adjusted P =1.00). CONCLUSIONS: Taking BIS value as the nursing observation index for PSH patients can make nursing work more objective, reasonable, and accurate, reduce the inducing factors of PSH attack, further reduce the attack of PSH, save nursing resources, and help guide the safety assessment of sedative use.
Asunto(s)
Monitores de Conciencia , Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Enfermedades del Sistema Nervioso Autónomo/diagnóstico , Enfermedades del Sistema Nervioso Autónomo/fisiopatología , Unidades de Cuidados Intensivos , Convulsiones , Anciano , Monitoreo Fisiológico/métodosRESUMEN
BACKGROUND AND PURPOSE: Bispectral Index (BIS) and University of Michigan Sedation Scale (UMSS) were two commonly used methods of monitoring the sedation depth, but their correlation was not clear. The purpose of this study is to ascertain if BIS correlates with UMSS in determining the sedation level during pediatric drug-induced sleep endoscopy (DISE). METHODS: One-hundred children, aged 36-143 months, with ASA I~II grade, were enrolled. They were subject to general anesthesia for an elective adenotonsillectomy. Two drug regimens were used. After UMSS ≥ 3, the sites of airway obstructions were located by checking the supraglottic airway structures with a fibrous laryngoscope. UMSS scores, BIS values, electromyography (EMG), and signal quality indices (SQIs) were recorded at the pre-medication and pre-DISE baseline (T0), 5 min subsequent to medication administration but prior to DISE initiation (T1), 1 min after DISE was initiated (T2), 1 min after DISE was completed (T3), 1 min subsequent to tracheal intubation (T4), 1 min following extubation (T5), and 30 min past extubation (T6). RESULTS: There were strong correlations between BIS monitor readings and UMSS scores for total and two regimens. Kappa values revealed moderate agreement between BIS and UMSS for total and two regimens. The agreement rates were 67.47% for the total, 61.43% for Regimen 1, and 73.42% for Regimen 2, respectively. CONCLUSION: BIS correlates with UMSS in determining the sedation level during pediatric DISE for two regimens. BIS might serve as an appropriate indicator of sedation intensity when UMSS could not be used.
Asunto(s)
Sedación Consciente , Endoscopía , Tonsilectomía , Humanos , Masculino , Femenino , Niño , Preescolar , Adenoidectomía , Hipnóticos y Sedantes/administración & dosificación , Monitores de Conciencia , Anestesia General , ElectromiografíaRESUMEN
BACKGROUND: The bispectral index (BIS) monitor is the most frequently used electroencephalogram (EEG)-based depth of anesthesia (DoA) technology in Norwegian hospitals. However, there is limited knowledge regarding the extent and clinical impact of its use and how anesthesiologists and nurse anesthetists use the information provided by the DoA monitors in their clinical practice. METHODS: This cross-sectional survey on the use of DoA monitors in Norway used a web-based questionnaire distributed to anesthesia personnel in all hospitals in Norway. Participation was voluntary and anonymized, and the web form could not track IP sources or respondents' locations. RESULTS: Three hundred and ninety-one nurse anesthetists (n = 324) and anesthesiologists (n = 67) responded. Among the EEG-based DoA monitoring tools, BIS was most often used to observe and assess patients' DoA (98%). Raw EEG waveform analysis (10%), EEG-spectrogram (9%), and suppression rate (10%) were seldom used. Twenty-seven percent of the anesthesia personnel were able to recognize a burst suppression pattern on EEG and its significance. Fifty-eight percent of the respondents considered clinical observations more reliable than BIS. Almost all respondents reported adjusting anesthetic dosage based on the BIS index values (80%). However, the anesthetic dose was more often increased (90%) because of high BIS index values than lowered (55%) because of low BIS index values. CONCLUSION: Despite our respondents' extensive use of DoA monitoring, the anesthesia personnel in our survey did not use all the information and the potential to guide the titration of anesthetics the DoA monitors provide. Thus, anesthesia personnel could generally benefit from increased knowledge of how EEG-based DoA monitoring can be used to assess and determine individual patients' need for anesthetic medication.
Asunto(s)
Electroencefalografía , Internet , Humanos , Noruega , Estudios Transversales , Encuestas y Cuestionarios , Monitoreo Intraoperatorio/métodos , Anestesiólogos , Enfermeras Anestesistas , Anestesia/métodos , Masculino , Femenino , Monitores de Conciencia , AdultoRESUMEN
PURPOSE: Continuous cerebrovascular reactivity monitoring in both neurocritical and intra-operative care has gained extensive interest in recent years, as it has documented associations with long-term outcomes (in neurocritical care populations) and cognitive outcomes (in operative cohorts). This has sparked further interest into the exploration and evaluation of methods to achieve an optimal cerebrovascular reactivity measure, where the individual patient is exposed to the lowest insult burden of impaired cerebrovascular reactivity. Recent literature has documented, in neural injury populations, the presence of a potential optimal sedation level in neurocritical care, based on the relationship between cerebrovascular reactivity and quantitative depth of sedation (using bispectral index (BIS)) - termed BISopt. The presence of this measure outside of neural injury patients has yet to be proven. METHODS: We explore the relationship between BIS and continuous cerebrovascular reactivity in two cohorts: (A) healthy population undergoing elective spinal surgery under general anesthesia, and (B) healthy volunteer cohort of awake controls. RESULTS: We demonstrate the presence of BISopt in the general anesthesia population (96% of patients), and its absence in awake controls, providing preliminary validation of its existence outside of neural injury populations. Furthermore, we found BIS to be sufficiently separate from overall systemic blood pressure, this indicates that they impact different pathophysiological phenomena to mediate cerebrovascular reactivity. CONCLUSIONS: Findings here carry implications for the adaptation of the individualized physiologic BISopt concept to non-neural injury populations, both within critical care and the operative theater. However, this work is currently exploratory, and future work is required.
Asunto(s)
Anestesia General , Monitores de Conciencia , Electroencefalografía , Humanos , Masculino , Femenino , Persona de Mediana Edad , Adulto , Electroencefalografía/métodos , Circulación Cerebrovascular , Voluntarios Sanos , Presión Sanguínea , Monitoreo Intraoperatorio/métodos , Anciano , Vigilia , Reproducibilidad de los Resultados , Cuidados Críticos/métodos , Adulto JovenRESUMEN
BACKGROUND: Remimazolam is a safe and effective new benzodiazepine sedative that has unique advantages in anesthesia induction and maintenance. The differences in the electroencephalogram bispectral index (BIS) during general anesthesia between propofol and remimazolam deserve further exploration. METHODS: Single-center randomized crossover study. Patients who required multiple hysteroscopic surgery were randomly assigned to use remimazolam (0.27 mg/kg for induction and 1 mg/kg/h for maintenance) first and then propofol (2.0 mg/kg for induction and 6 mg/kg/h for maintenance) during hysteroscopic surgery again 3 months later, or in the opposite order. Both drugs were used at the latest ED95 for unconsciousness. The BIS values (primary endpoint), intraoperative conditions, and incidence of adverse reactions (secondary endpoints) were compared at each time point. BIS values were analyzed with a mixed model of repeated measurements (MMRM). RESULTS: Seventeen patients completed the study. The lowest BIS value in the remimazolam regimen was significantly higher than that in the propofol regimen (p = 0.001). The MMRM analysis of the BIS values revealed significant differences between the regimens at each time point (p < 0.001). The intraoperative diastolic blood pressure and heart rate changes were smaller, the recovery was faster, and there were fewer adverse reactions and less injection pain, but a greater incidence of intraoperative body movement and hiccups, in the remimazolam regimen. CONCLUSION: The trial indicated that remimazolam maintained a higher BIS level than propofol. The correlation between the BIS and the depth of anesthesia induced by remimazolam needs to be further studied. TRIAL REGISTRATION: This trial is registered at ClinicalTrials.gov: ChiCTR2200064551.
Asunto(s)
Anestesia General , Benzodiazepinas , Estudios Cruzados , Electroencefalografía , Hipnóticos y Sedantes , Propofol , Humanos , Femenino , Propofol/administración & dosificación , Propofol/efectos adversos , Adulto , Anestesia General/métodos , Benzodiazepinas/administración & dosificación , Benzodiazepinas/efectos adversos , Persona de Mediana Edad , Electroencefalografía/efectos de los fármacos , Hipnóticos y Sedantes/administración & dosificación , Hipnóticos y Sedantes/efectos adversos , Monitores de Conciencia , Anestésicos Intravenosos/administración & dosificación , Anestésicos Intravenosos/efectos adversos , Histeroscopía/efectos adversos , Histeroscopía/métodosRESUMEN
The electroencephalographic (EEG) activity during anesthesia emergence contains information about the risk for a patient to experience postoperative delirium, but the EEG dynamics during emergence challenge monitoring approaches. Substance-specific emergence characteristics may additionally limit the reliability of commonly used processed EEG indices during emergence. This study aims to analyze the dynamics of different EEG indices during anesthesia emergence that was maintained with different anesthetic regimens. We used the EEG of 45 patients under general anesthesia from the emergence period. Fifteen patients per group received sevoflurane, isoflurane (+ sufentanil) or propofol (+ remifentanil) anesthesia. One channel EEG and the bispectral index (BIS A-1000) were recorded during the study. We replayed the EEG back to the Conox, Entropy Module, and the BIS Vista to evaluate and compare the index behavior. The volatile anesthetics induced significantly higher EEG frequencies, causing higher indices (AUC > 0.7) over most parts of emergence compared to propofol. The median duration of "awake" indices (i.e., > 80) before the return of responsiveness (RoR) was significantly longer for the volatile anesthetics (p < 0.001). The different indices correlated well under volatile anesthesia (rs > 0.6), with SE having the weakest correlation. For propofol, the correlation was lower (rs < 0.6). SE was significantly higher than BIS and, under propofol anesthesia, qCON. Systematic differences of EEG-based indices depend on the drugs and devices used. Thus, to avoid early awareness or anesthesia overdose using an EEG-based index during emergence, the anesthetic regimen, the monitor used, and the raw EEG trace should be considered for interpretation before making clinical decisions.
Asunto(s)
Periodo de Recuperación de la Anestesia , Anestésicos por Inhalación , Monitores de Conciencia , Electroencefalografía , Propofol , Sevoflurano , Humanos , Electroencefalografía/métodos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Propofol/administración & dosificación , Sevoflurano/administración & dosificación , Anestésicos por Inhalación/administración & dosificación , Anestesia General , Isoflurano/administración & dosificación , Reproducibilidad de los Resultados , Remifentanilo/administración & dosificación , Sufentanilo/administración & dosificación , Anestésicos Intravenosos/administración & dosificación , Anciano , Monitoreo Fisiológico/métodos , Piperidinas , Monitoreo Intraoperatorio/métodosRESUMEN
BACKGROUND: During spinal surgery, the motor tracts can be monitored using muscle-recorded transcranial electrical stimulation motor-evoked potentials (mTc-MEPs). We aimed to investigate the association of anesthetic and physiological parameters with mTc-MEPs. METHODS: Intraoperative mTc-MEP amplitudes, mTc-MEP area under the curves (AUC), and anesthetic and physiological measurements were collected retrospectively from the records of 108 consecutive patients undergoing elective spinal surgery. Pharmacological parameters of interest included propofol and opioid concentration, ketamine and noradrenaline infusion rates. Physiological parameters recorded included mean arterial pressure (MAP), bispectral index (BIS), heart rate, hemoglobin O 2 saturation, temperature, and Et co2 . A forward selection procedure was performed using multivariable mixed model analysis. RESULTS: Data from 75 (69.4%) patients were included. MAP and BIS were significantly associated with mTc-MEP amplitude ( P < .001). mTc-MEP amplitudes increased by 6.6% (95% confidence interval [CI], 2.7%-10.4%) per 10 mm Hg increase in MAP and by 2.79% (CI, 2.26%-3.32%) for every unit increase in BIS. MAP ( P < .001), BIS ( P < .001), heart rate ( P = .01), and temperature ( P = .02) were significantly associated with mTc-MEP AUC. The AUC increased by 7.5% (CI, 3.3%-11.7%) per 10 mm Hg increase of MAP, by 2.98% (CI, 2.41%-3.54%) per unit increase in BIS, and by 0.68% (CI, 0.13%-1.23%) per beat per minute increase in heart rate. mTc-MEP AUC decreased by 21.4% (CI, -38.11% to -3.98%) per degree increase in temperature. CONCLUSIONS: MAP, BIS, heart rate, and temperature were significantly associated with mTc-MEP amplitude and/or AUC. Maintenance of BIS and MAP at the high normal values may attenuate anesthetic effects on mTc-MEPs.
Asunto(s)
Potenciales Evocados Motores , Humanos , Masculino , Femenino , Potenciales Evocados Motores/efectos de los fármacos , Persona de Mediana Edad , Estudios Retrospectivos , Anciano , Presión Arterial/efectos de los fármacos , Estudios Longitudinales , Adulto , Análisis Multivariante , Frecuencia Cardíaca/efectos de los fármacos , Monitorización Neurofisiológica Intraoperatoria/métodos , Estimulación Transcraneal de Corriente Directa , Monitores de Conciencia , Analgésicos Opioides , Norepinefrina/sangre , Propofol/administración & dosificaciónRESUMEN
Mode decomposition is a method for extracting the characteristic intrinsic mode function (IMF) from various multidimensional time-series signals. Variational mode decomposition (VMD) searches for IMFs by optimizing the bandwidth to a narrow band with the [Formula: see text] norm while preserving the online estimated central frequency. In this study, we applied VMD to the analysis of electroencephalogram (EEG) recorded during general anesthesia. Using a bispectral index monitor, EEGs were recorded from 10 adult surgical patients (the median age: 47.0, and the percentile range: 27.0-59.3 years) who were anesthetized with sevoflurane. We created an application named EEG Mode Decompositor, which decomposes the recorded EEG into IMFs and displays the Hilbert spectrogram. Over the 30-min recovery from general anesthesia, the median (25-75 percentile range) bispectral index increased from 47.1 (42.2-50.4) to 97.4 (96.5-97.6), and the central frequencies of IMF-1 showed a significant change from 0.4 (0.2-0.5) Hz to 0.2 (0.1-0.3) Hz. IMF-2, IMF-3, IMF-4, IMF-5, and IMF-6 increased significantly from 1.4 (1.2-1.6) Hz to 7.5 (1.5-9.3) Hz, 6.7 (4.1-7.6) Hz to 19.4 (6.9-20.0) Hz, 10.9 (8.8-11.4) Hz to 26.4 (24.2-27.2) Hz, 13.4 (11.3-16.6) Hz to 35.6 (34.9-36.1) Hz, and 12.4 (9.7-18.1) Hz to 43.2 (42.9-43.4) Hz, respectively. The characteristic frequency component changes in specific IMFs during emergence from general anesthesia were visually captured by IMFs derived using VMD. EEG analysis by VMD is useful for extracting distinct changes during general anesthesia.
Asunto(s)
Anestesia General , Electroencefalografía , Adulto , Humanos , Persona de Mediana Edad , Sevoflurano , Monitores de ConcienciaRESUMEN
Depth of anaesthesia monitors can fail to detect consciousness under anaesthesia, primarily because they rely on the frontal EEG, which does not arise from a neural correlate of consciousness. A study published in a previous issue of the British Journal of Anaesthesia showed that indices produced by the different commercial monitors can give highly discordant results when analysing changes in the frontal EEG. Anaesthetists could benefit from routinely assessing the raw EEG and its spectrogram, rather than relying solely on an index produced by a depth of anaesthesia monitor.
Asunto(s)
Anestesia , Humanos , Monitores de Conciencia , Estado de Conciencia , Electroencefalografía/métodosRESUMEN
This paper proposed a new depth of anaesthesia (DoA) index for the real-time assessment of DoA using electroencephalography (EEG). In the proposed new DoA index, a wavelet transform threshold was applied to denoise raw EEG signals, and five features were extracted to construct classification models. Then, the Gaussian process regression model was employed for real-time assessment of anaesthesia states. The proposed real-time DoA index was implemented using a sliding window technique and validated using clinical EEG data recorded with the most popular commercial DoA product Bispectral Index monitor (BIS). The results are evaluated using the correlation coefficients and Bland-Altman methods. The outcomes show that the highest and the average correlation coefficients are 0.840 and 0.814, respectively, in the testing dataset. Meanwhile, the scatter plot of Bland-Altman shows that the agreement between BIS and the proposed index is 94.91%. In contrast, the proposed index is free from the electromyography (EMG) effect and surpasses the BIS performance when the signal quality indicator (SQI) is lower than 15, as the proposed index can display high correlation and reliable assessment results compared with clinic observations.
Asunto(s)
Anestesia , Electroencefalografía , Monitores de Conciencia , Electroencefalografía/métodos , Electromiografía , Análisis de OndículasRESUMEN
BACKGROUND: BIS (a brand of processed electroencephalogram [EEG] depth-of-anesthesia monitor) scores have become interwoven into clinical anesthesia care and research. Yet, the algorithms used by such monitors remain proprietary. We do not actually know what we are measuring. If we knew, we could better understand the clinical prognostic significance of deviations in the score and make greater research advances in closed-loop control or avoiding postoperative cognitive dysfunction or juvenile neurological injury. In previous work, an A-2000 BIS monitor was forensically disassembled and its algorithms (the BIS Engine) retrieved as machine code. Development of an emulator allowed BIS scores to be calculated from arbitrary EEG data for the first time. We now address the fundamental questions of how these algorithms function and what they represent physiologically. METHODS: EEG data were obtained during induction, maintenance, and emergence from 12 patients receiving customary anesthetic management for orthopedic, general, vascular, and neurosurgical procedures. These data were used to trigger the closely monitored execution of the various parts of the BIS Engine, allowing it to be reimplemented in a high-level language as an algorithm entitled ibis. Ibis was then rewritten for concision and physiological clarity to produce a novel completely clear-box depth-of-anesthesia algorithm titled openibis . RESULTS: The output of the ibis algorithm is functionally indistinguishable from the native BIS A-2000, with r = 0.9970 (0.9970-0.9971) and Bland-Altman mean difference between methods of -0.25 ± 2.6 on a unitless 0 to 100 depth-of-anesthesia scale. This precision exceeds the performance of any earlier attempt to reimplement the function of the BIS algorithms. The openibis algorithm also matches the output of the native algorithm very closely ( r = 0.9395 [0.9390-0.9400], Bland-Altman 2.62 ± 12.0) in only 64 lines of readable code whose function can be unambiguously related to observable features in the EEG signal. The operation of the openibis algorithm is described in an intuitive, graphical form. CONCLUSIONS: The openibis algorithm finally provides definitive answers about the BIS: the reliance of the most important signal components on the low-gamma waveband and how these components are weighted against each other. Reverse engineering allows these conclusions to be reached with a clarity and precision that cannot be obtained by other means. These results contradict previous review articles that were believed to be authoritative: the BIS score does not appear to depend on a bispectral index at all. These results put clinical anesthesia research using depth-of-anesthesia scores on a firm footing by elucidating their physiological basis and enabling comparison to other animal models for mechanistic research.
Asunto(s)
Anestesia , Anestesiología , Anestésicos , Algoritmos , Monitores de Conciencia , ElectroencefalografíaRESUMEN
BACKGROUND: Bispectral index (BIS) monitoring uses electroencephalographic data as an indicator of patients' consciousness level. This technology might be a useful adjunct to clinical observation when titrating sedative medications for palliative care patients. However, the use of BIS in palliative care generally, and in the UK in particular, is under-researched. A key area is this technology's acceptability for palliative care service users. Ahead of trialling BIS in practice, and in order to ascertain whether such a trial would be reasonable, we conducted a study to explore UK palliative care patients' and relatives' perceptions of the technology, including whether they thought its use in palliative care practice would be acceptable. METHODS: A qualitative exploration was undertaken. Participants were recruited through a UK hospice. Focus groups and semi-structured interviews were conducted with separate groups of palliative care patients, relatives of current patients, and bereaved relatives. We explored their views on acceptability of using BIS with palliative care patients, and analysed their responses following the five key stages of the Framework method. RESULTS: We recruited 25 participants. There were ten current hospice patients in three focus groups, four relatives of current patients in one focus group and one individual interview, and eleven bereaved relatives in three focus groups and two individual interviews. Our study participants considered BIS acceptable for monitoring palliative care patients' consciousness levels, and that it might be of use in end-of-life care, provided that it was additional to (rather than a replacement of) usual care, and patients and/or family members were involved in decisions about its use. Participants also noted that BIS, while possibly obtrusive, is not invasive, with some seeing it as equivalent to wearable technological devices such as activity watches. CONCLUSIONS: Participants considered BIS technology might be of benefit to palliative care as a non-intrusive means of assisting clinical assessment and decision-making at the end of life, and concluded that it would therefore be acceptable to trial the technology with patients.