Index of Consciousness monitoring may effectively predict and prevent circulatory stress induced by endotracheal intubation under general anesthesia: a prospective randomized controlled trial.

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).

Application value of dexmedetomidine in anesthesia for elderly patients undergoing radical colon cancer surgery.

BACKGROUND: Colon cancer presents a substantial risk to the well-being of elderly people worldwide. With advancements in medical technology, surgical treatment has become the primary approach for managing colon cancer patients. However, due to age-related physiological changes, especially a decline in cognitive function, older patients are more susceptible to the effects of surgery and anesthesia, increasing the relative risk of postoperative cognitive dysfunction (POCD). Therefore, in the surgical treatment of elderly patients with colon cancer, it is of paramount importance to select an appropriate anesthetic approach to reduce the occurrence of POCD, protect brain function, and improve surgical success rates. AIM: To explore the value of dexmedetomidine (Dex) in anesthesia for elderly patients undergoing radical colon cancer surgery. METHODS: One hundred and seventeen patients with colon cancer who underwent elective surgery under general anesthesia were selected and divided into two groups: A and B. Group A received Dex before anesthesia induction, and B group received an equivalent amount of normal saline. Changes in the mini-mental state examination, regional cerebral oxygen saturation (rSO2), bispectral index, glucose uptake rate (GluER), lactate production rate (LacPR), serum S100ß and neuron-specific enolase (NSE), POCD, and adverse anesthesia reactions were compared between the two groups. RESULTS: Surgical duration, duration of anesthesia, and intraoperative blood loss were comparable between the two groups (P > 0.05). The overall dosage of anesthetic drugs used in group A, including propofol and remifentanil, was significantly lower than that used in group B (P < 0.05). Group A exhibited higher rSO2 values at the time of endotracheal intubation, 30 min after the start of surgery, and immediately after extubation, higher GluER values and lower LacPR values at the time of endotracheal intubation, 30 min after the start of surgery, immediately after extubation, and 5 min after extubation (P < 0.05). Group A exhibited lower levels of serum S100ß and NSE 24 h postoperatively and a lower incidence of cognitive dysfunction on the 1st and 5th postoperative days (P < 0.05). CONCLUSION: The use of Dex in elderly patients undergoing radical colon cancer surgery helps maintain rSO2 Levels and reduce cerebral metabolic levels and the incidence of anesthesia- and surgery-induced cognitive dysfunction.

Bispectral Index Monitoring Effect on Delirium Occurrence and Nursing Quality Improvement in Post-anesthesia Care Unit Patients Recovering From General Anesthesia: A Randomized Controlled Trial.

BACKGROUND: The effect of intraoperative anesthesia depth monitoring on delirium occurrence and improvement of nursing quality in the post-anesthesia care unit (PACU) remains unclear. We aimed to explore the effect of intraoperative anesthesia bispectral index (BIS) monitoring on delirium occurrence and improvement of nursing quality in the PACU for patients recovering from general anesthesia. METHODS:  This randomized controlled trial included 120 patients, aged 20-80 years, classified as grades I-III according to the American Society of Anesthesiologists. The BIS-guided group (group B) underwent intraoperative monitoring of BIS anesthesia depth (maintained within the anesthetic range (40-60)). The depth of anesthesia was not monitored in the non-BIS-guided group (group C). The patient's vital signs were recorded at the beginning of the operation (T0), upon entering the PACU (T1), 15 min after extubation (T2), and after leaving the PACU (T3). Delirium score, emergence period (extubation and PACU observation times), and adverse events in the PACU were monitored. The nursing activity score (NAS) was used to evaluate the quality of care. RESULTS: Group B exhibited significantly lower heart rate and mean arterial pressure at T1 and T2, shorter time to extubation and PACU observation time, and a significantly lower incidence of adverse events than group C. Group B had significantly lower Ricker sedation-agitation scores and a lower incidence of delirium than group C. The NAS was significantly lower for group B than for group C. Patients aged 60-80 years in group C experienced agitation, requiring 30% more frequent assistance from one or two nurses than those in group B. CONCLUSION: Intraoperative BIS monitoring can reduce the incidence of adverse events in the PACU, diminish the incidence of delirium during the recovery period in elderly patients, lessen the nursing workload, improve nursing quality, and promote patient rehabilitation, thus meriting clinical application.

Effect of A118G (rs1799971) single-nucleotide polymorphism of the µ-opioid receptor OPRM1 gene on intraoperative remifentanil requirements in Japanese women undergoing laparoscopic gynecological surgery.

AIM: Abundant data are available on the effect of the A118G (rs1799971) single-nucleotide polymorphism (SNP) of the µ-opioid receptor OPRM1 gene on morphine and fentanyl requirements for pain control. However, data on the effect of this SNP on intraoperative remifentanil requirements remain limited. We investigated the effect of this SNP on intraoperative remifentanil requirements. METHODS: We investigated 333 Japanese women, aged 21-69 years, who underwent laparoscopic gynecological surgery for benign gynecological disease under total intravenous anesthesia at Juntendo University Hospital. Average infusion rates of propofol and remifentanil during anesthesia and the average bispectral index (BIS) during surgery were recorded. Associations among genotypes of the A118G and phenotypes were examined with the Mann-Whitney U test. RESULTS: The average propofol infusion rate was not different between patients with different genotypes. The average remifentanil infusion rate was significantly higher in patients with the AG or GG genotype than the AA genotype (p = 0.028). The average intraoperative BIS was significantly higher in patients with the GG genotype than the AA or AG genotype (p = 0.039). CONCLUSIONS: The G allele of the A118G SNP was associated with higher intraoperative remifentanil requirements and higher intraoperative BIS values but was not associated with propofol requirements. Given that remifentanil and propofol act synergistically on the BIS, these results suggest that the G allele of the A118G SNP is associated with lower effects of remifentanil in achieving adequate intraoperative analgesia and in potentiating the sedative effect of propofol on the BIS.

Predictive pharmacodynamic performance of the Eleveld pharmacokinetic-pharmacodynamic model for propofol: comparison of predicted and measured bispectral index.

BACKGROUND: The Eleveld pharmacokinetic-pharmacodynamic model for propofol predicts bispectral index (BIS) processed electroencephalogram values from estimated effect-site concentrations. We investigated agreement between measured and predicted BIS values during total intravenous anaesthesia (TIVA). METHODS: Forty participants undergoing lower limb surgery received TIVA using remifentanil target-controlled infusions and propofol by manually controlled, target-guided infusions based upon the Eleveld model and directed by two pharmacokinetic computer simulation applications: PKPD Tools and StelSim. We evaluated the predictive performance of the Eleveld model by calculating median prediction errors (BIS units) and by Bland-Altman analyses. We also performed |Bland-Altman analysis of supplementary data provided by the authors of the Eleveld model. RESULTS: Whereas median prediction errors were small (MDPE -1.9, MDAPE 10), the ranges were wide (-18.5 to 24.3 and 1.7 to 24.3). The proportion of MDAPE >10 BIS units was 47.8%. Bland-Altman analysis showed a small mean bias (-0.52 BIS units) with wide limits of agreement (-27.7 to 26.2). Each participant's limits of agreement did not meet the requirements for declaring interchangeability between the two measurements. The measurement differences depended on the BIS values, as indicated by the positive slopes of the differences vs BIS values. Bland-Altman analysis of the Eleveld model supplementary data revealed similar results. CONCLUSION: BIS predictions by the Eleveld model should be interpreted with caution. In spite of the acceptable MDPE and MDAPE, there are unacceptable degrees of both within-subject and between-subject variation during propofol target-controlled infusions. This limits the use of adjusting targeted concentrations to achieve desired simulated BIS values with confidence.

Potential increased propofol sensitivity in cognitively impaired elderly: a controlled, double-blind study.

Background: Cognitive impairment in the elderly may lead to potential increased sensitivity to anesthetic agents targeting receptors associated with cognition. This study aimed to explore the effect of cognitive status on propofol consumption during surgery in elderly patients. Methods: Sixty elderly patients scheduled for laparoscopic radical prostatectomy were allocated to either a cognitively normal [CogN, Montreal Cognitive Assessment (MoCA) score ≥26] or cognitively impaired (CogI, MoCA <26) group. Propofol was administered via target-controlled infusion to maintain a bispectral index (BIS) between 55-65 during surgery. Propofol consumption was recorded at three time points: T1 (abolished eyelash reflex), T2 (BIS = 50), T3 (extubation). BIS values at eyelash reflex abolition were also recorded. Postoperative MoCA, Visual Analogue Scale (VAS) scores, and remifentanil/sufentanil consumption were assessed. Results: BIS values before induction were similar between CogN and CogI groups. However, at eyelash reflex abolition, BIS was significantly higher in CogI than CogN (mean ± SD: 65.3 ± 7.2 vs. 61.1 ± 6.8, p = 0.031). Propofol requirement to reach BIS 50 was lower in CogI vs. CogN (1.24 ± 0.19 mg/kg vs. 1.46 ± 0.12 mg/kg, p = 0.003). Postoperative MoCA, VAS scores, and remifentanil/sufentanil consumption did not differ significantly between groups. Conclusion: Compared to cognitively intact elderly, those with cognitive impairment exhibited higher BIS at eyelash reflex abolition and required lower propofol doses to achieve the same BIS level, suggesting increased propofol sensitivity. Cognitive status may impact anesthetic medication requirements in the elderly.

Study of Two Sedative Protocols for Drug-Induced Sleep Endoscopy: Propofol versus Propofol-Remifentanil Combination, Delivered in Target-Controlled Infusion Mode.

Background and Objectives: Obstructive sleep apnea (OSA) is a prevalent sleep-disordered breathing pathology with significant clinical consequences, including increased cardiovascular risk and cognitive decline. Continuous positive airway pressure (CPAP) is the gold-standard treatment, but alternative strategies are sometimes needed for patients intolerant to CPAP. Drug-induced sleep endoscopy (DISE) is a key diagnostic tool for assessing upper airway obstruction in OSA patients and subsequently tailoring a surgical approach, with sedation protocols playing a crucial role in its efficacy and results accuracy. This study aimed to investigate the effect of adding remifentanil to a propofol target-controlled infusion (TCI) regimen on the sedation parameters and procedural outcomes of DISE. Materials and Methods: The study was conducted at the Central University and Emergency Military Hospital "Dr. Carol Davila" and Ria Clinic in Bucharest between July 2021 and October 2023. Thirty-one patients were enrolled and randomised into two groups: a propofol group (P group, n= 11) and a remifentanil-propofol group (R-P group, n = 20). DISE was performed using standardised protocols, sedative drugs were administered in TCI mode, and data on sedation levels, respiratory and cardiovascular parameters, and procedural incidents were collected. Results: The addition of remifentanil at 1 ng/mL effect-site concentration significantly reduced the effect-site concentration of propofol required for adequate sedation (3.4 ± 0.7 µg/mL in the P group vs. 2.8 ± 0.6 µg/mL in the R-P group, p = 0.035). The time to achieve adequate sedation was also shorter in the R-P group (7.1 ± 2.5 min vs. 9.5 ± 2.7 min, p = 0.017). The incidence of cough, hypoxemia, and cardiovascular events did not significantly differ between the two groups. Conclusions: Adding remifentanil to a propofol TCI regimen for DISE effectively reduces the required propofol effect-site concentration and shortens sedation time without increasing the risk of adverse events. This combination may enhance the safety and efficiency of DISE, offering a promising alternative for patients undergoing this procedure.

Understanding time to peak effect of propofol as sole agent on bispectral index in children aged 2-12 years.

BACKGROUND: The pharmacodynamics of propofol in children have previously been described with the proprietary bispectral index (BIS) as an effect-site marker, and it has been suggested that the rate of onset of propofol might be age dependent, that is, a shorter time to peak effect in younger children. However, these analyses were potentially confounded by co-administered drugs, in particular opioids and benzodiazepines. Thus, the goal of this prospective study was to characterize the influence of age and weight on the onset of hypnotic effects from propofol, reflected by the time to peak of propofol effect-site concentration in the absence of additional drugs. METHODS: A total of 46 healthy children aged 2-12 years presenting for elective surgery were included in our observational cohort study. Solely propofol was administered via a target-controlled infusion pump programmed with the Paedfusor pharmacokinetic model. The BIS and infusion pump data were recorded. The effect of an induction "bolus" was recorded having stopped the pump once a propofol plasma target concentration of 7 µg.mL-1 was achieved. A direct-response and an indirect-response model in the context of nonlinear mixed-effects modeling was used to characterize and compare BIS data in children aged 2-6 years and older children aged 8-12 years. RESULTS: Time to peak of propofol effect-site concentration had a difference (p-value <.01) for age and weight, that is 84 [74, 96] (median [IQR] secs for children aged 2-6 years vs. 99 [91, 113] secs for children aged 8-12 years and 82 [71, 95] secs for weight 11-25 kg vs. 99 [91, 114] secs for weight 30-63 kg). The plasma effect-site equilibration rate constant for propofol had a heterogeneous distribution with a median of 2.36 (IQR: 2.05-2.93; range: 0.83-7.31) per minute but showed a weight-dependent effect in patients with weight below 45 kg. CONCLUSIONS: In children, the age and weight have an influence on time to peak effect of propofol. In the absence of opioids and benzodiazepines, time to peak effect was approximately 20% longer in children aged 8-12 years as compared to younger children. Such clinically relevant age and weight effects are an important consideration in the individualized titration of propofol dosing.

Comparing Bispectral Index Monitoring vs Clinical Assessment for Deep Sedation in the ICU: Effects on Delirium Reduction and Sedative Drug Doses-A Randomized Trial.

BACKGROUND: Sedative overdoses pose a risk of delirium among patients in the ICU, with potential mitigation through the use of a processed EEG monitor (the bispectral index [BIS]) to guide depth of sedation. RESEARCH QUESTION: Can BIS-guided deep sedation (Richmond Agitation Sedation Scale RASS score, -4 or -5) reduce sedative dosage and increase delirium-free and coma-free (DFCF) days? STUDY DESIGN AND METHODS: A randomized controlled trial was conducted in a tertiary mixed ICU, enrolling patients requiring deep sedation for > 8 h. Patients were assigned randomly to either the clinical assessment (CA) or BIS groups (BIS range, 40-60). Both groups used a BIS sensor, whereas the CA group's screen remained covered. After deep sedation, BIS sensors were removed, and delirium was assessed twice daily by researchers masked to the randomization. The primary outcome was the number of DFCF days within 14 days after deep sedation. Additionally, we compared doses of sedative drugs and BIS values during deep sedation. RESULTS: Ninety-nine patients were included in the study. We found no significant difference in DFCF days (P = .1) between CA and BIS arms, but propofol doses were significantly lower in the BIS group (CA group, 1.77 mg/kg/h [95% CI, 1.60-1.93] vs BIS group, 1.44 mg/kg/h [95% CI, 1.04-1.83]; P = .03). During deep sedation, the CA group spent 46% of the total hours (95% CI, 35%-57%) with BIS values of < 40, whereas the BIS group spent 32% (95% CI, 25%-40%; P = .03). Subgroup analysis focusing on patients sedated for > 24 h revealed an increase in DFCF days in the BIS group (CA group: median, 1 day [interquartile range (IQR), 0-9 days] vs BIS group: median, 8 days [IQR, 0-13 days]; P = .04). INTERPRETATION: BIS-guided deep sedation did not improve DFCF days, but did reduce sedative drug use. In patients requiring sedation for > 24 h, it showed an improvement in DFCF days. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT03840577; URL: www. CLINICALTRIALS: gov.

Bispectral Index monitoring of palliative sedation for home withdrawal of tracheostomy ventilation: A case report.

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.

Assessment of depth of sedation using Bispectral Index™ monitoring in patients with severe traumatic brain injury in UK intensive care units.

Introduction: Severe traumatic brain injury affects ∼4500 per year across the UK. Most patients undergo a period of sedation to prevent secondary brain injury, however the optimal sedation target is unclear. This study aimed to assess the relationship between the electroencephalogram (EEG)-based Bispectral Index™ (BIS™) value and the clinical sedation score, along with other clinical outcomes. Methods: Patients with severe traumatic brain injury in four UK ICUs were recruited to have blinded BIS data collected for a 24-h period while sedated on the ICU. Drug, physiological, and outcome data were recorded from the ICU record. Sedation management was at the discretion of the ICU clinical team. Results: Twenty-six participants were recruited to the study. The mean BIS was 38 (inter-quartile range 29-44) and there was poor correlation between BIS and sedation score as a group (correlation coefficient 0.17, 95% confidence interval 0.08-0.26), however the spread in BIS values increased with decreasing sedation score. There was no statistically significant relationship between BIS and intracranial pressure, vasopressor use, osmotherapy use, or need for an additional sedative. Conclusion: This study supports previous work showing that BIS decreases with decreasing sedation score. However, the variation in BIS values increased with deeper levels of clinical sedation. Patients may not be benefiting from the full potential of sedation in traumatic brain injury and further studies of sedation titrated to an EEG-based parameter are needed. Clinical trial registration: NCT03575169.

Effect of Continuous Infusion of Different Doses of Esketamine on the Bispectral Index During Sevoflurane Anesthesia: A Randomized Controlled Trial.

Purpose: To investigate and quantify the effect of continuous esketamine infusion at different doses on the bispectral index (BIS) during sevoflurane anesthesia. Methods: A total of 120 patients scheduled for elective laparoscopic renal surgery were randomly divided into three groups. Under steady anesthesia and surgical situations, the patient was started on continuous infusion of the study drug: 0.125 mg/kg/h esketamine (group E1), 0.25 mg/kg/h esketamine (group E2), and the same volume of saline (group C). The primary outcome was changes in BIS value after 15 min (T15), 30 min (T30), 45 min (T45), and 60 min (T60) of drug infusion. The secondary outcomes were 95% spectral edge frequency (SEF95), electromyogram (EMG), heart rate (HR), and mean arterial pressure (MAP) from T0 to T60. Furthermore, postoperative pain, postoperative recovery, and perioperative adverse events were evaluated. Results: Compared with group C, group E1 exhibited significant BIS elevation at T30-T60 and group E2 at T15-T60 (P < 0.001). Compared with group E1, group E2 showed a more significant BIS elevation at T15-T60 (P < 0.001). The area under the curve (AUC) of BIS and SEF95 were significantly higher in group E2 than in groups C and E1 (P < 0.05). BIS value for any of the three groups was significantly correlated with SEF95 (P < 0.001). No significant differences were observed in the AUC of EMG, HR, and MAP among the three groups. Intraoperative remifentanil consumption and postoperative NRS of pain on movement were significantly reduced in group E2 compared with groups C and E1 (P < 0.05). Conclusion: Continuous infusion of both 0.125 and 0.25 mg/kg/h of esketamine increased the BIS value during sevoflurane anesthesia, and the BIS value gradually stabilized with the prolongation of the infusion time.

Alternative sensor montage for Index based EEG monitoring. A systematic review.

The main objective of this systematic review is to assess the reliability of alternative positions of processed electroencephalogram sensors for depth of anesthesia monitoring and its applicability in clinical practice. A systematic search was conducted in PubMed, Embase, Cochrane Library, Clinical trial.gov in accordance with reporting guidelines of PRISMA statement together with the following sources: Google and Google Scholar. We considered eligible prospective studies, written in the English language. The last search was run on the August 2023. Risk of bias and quality assessment were performed. Data extraction was performed by two authors and results were synthesized narratively owing to the heterogeneity of the included studies. Thirteen prospective observational studies (438 patients) were included in the systematic review after the final assessment, with significant diversity in study design. Most studies had a low risk of bias but due to lack of information in one key domain of bias (Bias due to missing data) the overall judgement would be No Information. However, there is no clear indication that the studies are at serious or critical risk of bias. Bearing in mind, the heterogeneity and small sample size of the included studies, current evidence suggests that the alternative infraorbital sensor position is the most comparable for clinical use when the standard sensor position in the forehead is not possible.

Bispectral index-guided comparison of dexmedetomidine and fentanyl as an adjuvant with propofol to achieve an adequate depth for endotracheal intubation - A double-blind randomised controlled trial.

Background and Aims: Laryngoscopy and tracheal intubation require an adequate depth of anaesthesia. The study's primary objective was to compare the time needed to achieve the bispectral index (BIS)-guided adequate depth of anaesthesia for endotracheal intubation using fentanyl and dexmedetomidine. Methods: After institutional ethics committee clearance and written informed consent, this randomised study was conducted on 140 patients of either gender between 18 and 60 years who were scheduled for elective surgeries under general anaesthesia. Patients were randomised to intravenous dexmedetomidine 1 µg/kg (Group D) or fentanyl 2 µg/kg (Group F). The drugs were given as an intravenous infusion over 10 min before induction of anaesthesia. The primary outcome was the time required to achieve BIS 50. Normally distributed variables were compared using Student's t-test, and non-normally distributed variables were compared using the Mann-Whitney U test. Qualitative data were analysed using Chi-square/Fisher's exact test. A P value <0.05 was considered significant. Results: The time to achieve BIS 50 was lesser in Group F, 1546 (27) as compared to Group D, 1558 (11) s [mean difference (95% confidence interval (CI) 12[5.11, 18.89]), P < 0.001]. Haemodynamic parameters were comparable at all time points between both the groups, except heart rate, which was significantly lower. Propofol consumption was significantly less in group D than in group F [125.9 (25.36) versus 157.3 (42.80) mg, respectively, mean difference (95% CI) 31.4 (-44.16 to -20.63) P < 0.001)]. Conclusion: Dexmedetomidine achieves BIS 50 faster and has a propofol-sparing effect as compared to fentanyl.

Bispectral index monitoring for sedation in scheduled adult colonoscopy: A randomized controlled trial.

BACKGROUND: Patients should be closely monitored during procedures under sedation outside the operating room, but it is unclear which type of monitoring is best. We investigated the efficacy and safety of BIS monitoring vs conventional monitoring for sedation during colonoscopy. METHODS: We performed a double-blind clinical trial in 180 patients undergoing elective colonoscopy. Patients were randomized to 1) the BIS group or 2) a control group, in which sedation was monitored with a BIS monitor or the Ramsay Sedation Score, respectively. The primary outcome was the rate of sedation-induced adverse events in both groups. Secondary outcomes were the characteristics of patients who developed adverse events, and time during colonoscopy when these events occurred, propofol and remifentanil dosage, and patient satisfaction. RESULTS: Univariate analysis showed fewer cardiopulmonary complications in the BIS group (41.11% vs 57.78% in controls; p = 0.02). Multivariate analysis found a significantly higher risk of adverse events in older patients (95% CI, 1.013-1.091; p = 0.0087) and in men (95% CI, 1.129-7.668; p = 0.0272). These events were observed at the hepatic flexure. No significant differences between propofol or remifentanil dosage, use of rescue medication, and patient satisfaction were observed between groups. CONCLUSIONS: Our data suggest that BIS monitoring during sedation in scheduled colonoscopies reduces adverse respiratory events. Although its routine use in sedation does not appear to be warranted, clinicians should take steps to identify patients with a higher risk of complications who might benefit from this type of monitoring.

Use of bispectral index for detection of partial cerebral hypoperfusion during cervical spine surgery: A case report.

The BIS value may decrease by cerebral hypoperfusion. We report a case in which the BIS value suddenly decreased during cervical spine surgery, which led us to find cervical screws compressing the vertebral arteries. In a 79-year-old man undergoing cervical spine surgery, the BIS suddenly decreased from about 40 to 10-20, about 4 h after the start of surgery. Intraoperative 3-dementional computed tomography indicated that both the two tips of cervical screws inserted in the 6th cervical vertebra were within bilateral transverse foramens. These cervical screws were removed, and the BIS increased immediately. The cervical screws were re-inserted again thorough the same vertebra into the bilateral transverse foramens, and the BIS decreased immediately. Postoperatively, cerebral hypoperfusion due to compression of bilateral vertebral arteries by two cervical screws was identified. The BIS may be a useful to detect cerebral hypoperfusion due to compression of the vertebral artery by a cervical screw.

Bispectral Index versus the University of Michigan Sedation Scale in assessing sedation depth during pediatric drug-induced sleep endoscopy.

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.

Comparison of the bispectral indices of patients receiving remimazolam and propofol for general anesthesia: a randomized crossover trial.

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.

Identification of an effective and safe bolus dose and lockout time for patient-controlled sedation (PCS) using dexmedetomidine in dental treatments: a randomized clinical trial.

Background: This study investigated a safe and effective bolus dose and lockout time for patient-controlled sedation (PCS) with dexmedetomidine for dental treatments. The depth of sedation, vital signs, and patient satisfaction were investigated to demonstrate safety. Methods: Thirty patients requiring dental scaling were enrolled and randomly divided into three groups based on bolus doses and lockout times: group 1 (low dose group, bolus dose 0.05 µg/kg, 1-minute lockout time), group 2 (middle dose group, 0.1 µg/kg, 1-minute), and group 3 (high dose group, 0.2 µg/kg, 3-minute) (n = 10 each). ECG, pulse, oxygen saturation, blood pressure, end-tidal CO2, respiratory rate, and bispectral index scores (BIS) were measured and recorded. The study was conducted in two stages: the first involved sedation without dental treatment and the second included sedation with dental scaling. Patients were instructed to press the drug demand button every 10 s, and the process of falling asleep and waking up was repeated 1-5 times. In the second stage, during dental scaling, patients were instructed to press the drug demand button. Loss of responsiveness (LOR) was defined as failure to respond to auditory stimuli six times, determining sleep onset. Patient and dentist satisfaction were assessed before and after experimentation. Results: Thirty patients (22 males) participated in the study. Scaling was performed in 29 patients after excluding one who experienced dizziness during the first stage. The average number of drug administrations until first LOR was significantly lower in group 3 (2.8 times) than groups 1 and 2 (8.0 and 6.5 times, respectively). The time taken to reach the LOR showed no difference between groups. During the second stage, the average time required to reach the LOR during scaling was 583.4 seconds. The effect site concentrations (Ce) was significantly lower in group 1 than groups 2 and 3. In the participant survey on PCS, 8/10 in group 3 reported partial memory loss, whereas 17/20 in groups 1 and 2 recalled the procedure fully or partially. Conclusion: PCS with dexmedetomidine can provide a rapid onset of sedation, safe vital sign management, and minimal side effects, thus facilitating smooth dental sedation.

Intravenous Ganaxolone: Pharmacokinetics, Pharmacodynamics, Safety, and Tolerability in Healthy Adults.

Ganaxolone, a neuroactive steroid anticonvulsant that modulates both synaptic and extrasynaptic γ-aminobutyric acid type A (GABAA ) receptors, is in development for treatment of status epilepticus (SE) and rare epileptic disorders, and has been approved in the United States for treatment of seizures associated with cyclin-dependent kinase-like 5 deficiency disorder in patients ≥2 years old. This phase 1 study in 36 healthy volunteers evaluated the pharmacokinetics, pharmacodynamics, and safety of intravenous ganaxolone administered as a (i) single bolus, (ii) infusion, and (iii) bolus followed by continuous infusion. After a single bolus over 2 minutes (20 mg) or 5 minutes (10 or 30 mg), ganaxolone was detected in plasma with a median Tmax of 5 minutes, whereas a 60-minute infusion (10 or 30 mg) or a bolus (6 mg over 5 minutes) followed by infusion (20 mg/h) for 4 hours achieved a median Tmax of approximately 1 and 3 hours, respectively. Cmax was dose and administration-time dependent, ranging from 73.8 ng/mL (10 mg over 5 minutes) to 1240 ng/mL (30 mg over 5 minutes). Bolus doses above 10 mg of ganaxolone markedly influenced the bispectral index score with a rapid decline; smaller changes occurred on the Modified Observer's Assessment of Alertness/Sedation scale and in quantitative electroencephalogram. Most adverse events were of mild severity, with 2 events of moderate severity; none were reported as serious. No effects on systemic hemodynamics or respiratory functions were reported. Overall, ganaxolone was generally well tolerated at the doses studied and demonstrated pharmacokinetic and pharmacodynamic properties suitable to treat SE.