In Vivo Photoadduction of Anesthetic Ligands in Mouse Brain Markedly Extends Sedation and Hypnosis.

Photoaffinity ligands are best known as tools used to identify the specific binding sites of drugs to their molecular targets. However, photoaffinity ligands have the potential to further define critical neuroanatomic targets of drug action. In the brains of WT male mice, we demonstrate the feasibility of using photoaffinity ligands in vivo to prolong anesthesia via targeted yet spatially restricted photoadduction of azi-m-propofol (aziPm), a photoreactive analog of the general anesthetic propofol. Systemic administration of aziPm with bilateral near-ultraviolet photoadduction in the rostral pons, at the border of the parabrachial nucleus and locus coeruleus, produced a 20-fold increase in the duration of sedative and hypnotic effects compared with control mice without UV illumination. Photoadduction that missed the parabrachial-coerulean complex also failed to extend the sedative or hypnotic actions of aziPm and was indistinguishable from nonadducted controls. Paralleling the prolonged behavioral and EEG consequences of on target in vivo photoadduction, we conducted electrophysiologic recordings in rostral pontine brain slices. Using neurons within the locus coeruleus to further highlight the cellular consequences of irreversible aziPm binding, we demonstrate transient slowing of spontaneous action potentials with a brief bath application of aziPm that becomes irreversible on photoadduction. Together, these findings suggest that photochemistry-based strategies are a viable new approach for probing CNS physiology and pathophysiology.SIGNIFICANCE STATEMENT Photoaffinity ligands are drugs capable of light-induced irreversible binding, which have unexploited potential to identify the neuroanatomic sites of drug action. We systemically administer a centrally acting anesthetic photoaffinity ligand in mice, conduct localized photoillumination within the brain to covalently adduct the drug at its in vivo sites of action, and successfully enrich irreversible drug binding within a restricted 250 µm radius. When photoadduction encompassed the pontine parabrachial-coerulean complex, anesthetic sedation and hypnosis was prolonged 20-fold, thus illustrating the power of in vivo photochemistry to help unravel neuronal mechanisms of drug action.

The arousal level of consciousness required for working memory performance: An anaesthesia study.

Regarding the stage of arousal level required for working memory to function properly, limited studies have been conducted on changes in working memory performance when the arousal level of consciousness decreases. This study aimed to experimentally clarify the stages of consciousness necessary for optimal working memory function. In this experiment, the sedation levels were changed step-by-step using anaesthesia, and the performance accuracy during the execution of working memory was assessed using a dual-task paradigm. Participants were required to categorize and remember words in a specific target category. Categorization performance was measured across four different sedative phases: before anaesthesia (baseline), and deep, moderate and light stages of sedation. Short-delay recognition tasks were performed under these four sedative stages, followed by long-delay recognition tasks after participants recovered from sedation. The results of the short-delay recognition task showed that the performance was lowest at the deep stage. The performance of the moderate stage was lower than the baseline. In the long-delay recognition task, the performance under moderate sedation was lower than that under baseline and light sedation. In addition, the performance under light sedation was lower than that under baseline. These results suggest that task performance becomes difficult under half sedation and that transferring information to long-term memory is difficult even under one-quarter sedation.

Dexmedetomidine or Propofol for Sedation in Mechanically Ventilated Adults with Sepsis.

BACKGROUND: Guidelines currently recommend targeting light sedation with dexmedetomidine or propofol for adults receiving mechanical ventilation. Differences exist between these sedatives in arousability, immunity, and inflammation. Whether they affect outcomes differentially in mechanically ventilated adults with sepsis undergoing light sedation is unknown. METHODS: In a multicenter, double-blind trial, we randomly assigned mechanically ventilated adults with sepsis to receive dexmedetomidine (0.2 to 1.5 µg per kilogram of body weight per hour) or propofol (5 to 50 µg per kilogram per minute), with doses adjusted by bedside nurses to achieve target sedation goals set by clinicians according to the Richmond Agitation-Sedation Scale (RASS, on which scores range from -5 [unresponsive] to +4 [combative]). The primary end point was days alive without delirium or coma during the 14-day intervention period. Secondary end points were ventilator-free days at 28 days, death at 90 days, and age-adjusted total score on the Telephone Interview for Cognitive Status questionnaire (TICS-T; scores range from 0 to 100, with a mean of 50±10 and lower scores indicating worse cognition) at 6 months. RESULTS: Of 432 patients who underwent randomization, 422 were assigned to receive a trial drug and were included in the analyses - 214 patients received dexmedetomidine at a median dose of 0.27 µg per kilogram per hour, and 208 received propofol at a median dose of 10.21 µg per kilogram per minute. The median duration of receipt of the trial drugs was 3.0 days (interquartile range, 2.0 to 6.0), and the median RASS score was -2.0 (interquartile range, -3.0 to -1.0). We found no difference between dexmedetomidine and propofol in the number of days alive without delirium or coma (adjusted median, 10.7 vs. 10.8 days; odds ratio, 0.96; 95% confidence interval [CI], 0.74 to 1.26), ventilator-free days (adjusted median, 23.7 vs. 24.0 days; odds ratio, 0.98; 95% CI, 0.63 to 1.51), death at 90 days (38% vs. 39%; hazard ratio, 1.06; 95% CI, 0.74 to 1.52), or TICS-T score at 6 months (adjusted median score, 40.9 vs. 41.4; odds ratio, 0.94; 95% CI, 0.66 to 1.33). Safety end points were similar in the two groups. CONCLUSIONS: Among mechanically ventilated adults with sepsis who were being treated with recommended light-sedation approaches, outcomes in patients who received dexmedetomidine did not differ from outcomes in those who received propofol. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT01739933.).

Propofol vs etomidate for induction prior to invasive mechanical ventilation in patients with acute myocardial infarction.

BACKGROUND: Patients with acute myocardial infarction (AMI) requiring invasive mechanical ventilation (IMV) have a high mortality. However, little is known regarding the impact of induction agents, used prior to IMV, on clinical outcomes in this population. We assessed for the association between induction agent and mortality in patients with AMI requiring IMV. METHODS: We compared clinical outcomes between those receiving propofol compared to etomidate for induction among adults with AMI between October 2015 and December 2019 using the Vizient® Clinical Data Base, a multicenter, US national database. We used inverse probability treatment weighting (IPTW) to assess for the association between induction agent and in-hospital mortality. RESULTS: We identified 5,147 patients, 1,386 (26.9%) of received propofol and 3,761 (73.1%) received etomidate for IMV induction. The mean (SD) age was 66.1 (12.4) years, 33.0% were women, and 51.6% and 39.8% presented with STEMI and cardiogenic shock, respectively. Patients in the propofol group were more likely to require preintubation vasoactive medication and mechanical circulatory support (both, P < .05). Utilization of propofol was associated with lower mortality compared to etomidate (32.3% vs 36.1%, P = .01). After propensity weighting, propofol use remained associated with lower mortality (weighted mean difference -4.7%; 95% confidence interval: -7.6% to -1.8%, P = .002). Total cost, ventilator days, and length of stay were higher in the propofol group (all, P < .001). CONCLUSIONS: Induction with propofol, compared with etomidate, was associated with lower mortality for patients with AMI requiring IMV. Randomized trials are needed to determine the optimal induction agent for this critically ill patient population.

Analgesia and Sedation Use During Noninvasive Ventilation for Acute Respiratory Failure.

OBJECTIVES: To describe U.S. practice regarding administration of sedation and analgesia to patients on noninvasive ventilation (NIV) for acute respiratory failure (ARF) and to determine the association of this practice with odds of intubation or death. DESIGN: A retrospective multicenter cohort study. SETTING: A total of 1017 hospitals contributed data between January 2010 and September 2020 to the Premier Healthcare Database, a nationally representative healthcare database in the United States. PATIENTS: Adult (≥ 18 yr) patients admitted to U.S. hospitals requiring NIV for ARF. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We identified 433,357 patients on NIV of whom (26.7% [95% CI] 26.3%-27.0%) received sedation or analgesia. A total of 50,589 patients (11.7%) received opioids only, 40,646 (9.4%) received benzodiazepines only, 20,146 (4.6%) received opioids and benzodiazepines, 1.573 (0.4%) received dexmedetomidine only, and 2,639 (0.6%) received dexmedetomidine in addition to opioid and/or benzodiazepine. Of 433,357 patients receiving NIV, 50,413 (11.6%; 95% CI, 11.5-11.7%) patients underwent invasive mechanical ventilation on hospital days 2-5 or died on hospital days 2-30. Intubation was used in 32,301 patients (7.4%; 95% CI, 7.3-7.6%). Further, death occurred in 24,140 (5.6%; 95% CI, 5.5-5.7%). In multivariable analysis adjusting for relevant covariates, receipt of any medication studied was associated with increased odds of intubation or death. In inverse probability weighting, receipt of any study medication was also associated with increased odds of intubation or death (average treatment effect odds ratio 1.38; 95% CI, 1.35-1.40). CONCLUSIONS: The use of sedation and analgesia during NIV is common. Medication exposure was associated with increased odds of intubation or death. Further investigation is needed to confirm this finding and determine whether any subpopulations are especially harmed by this practice.

Successful and Rapid Reduction in Neurosedative and Analgesic Medications in Complex Infants with Severe Bronchopulmonary Dysplasia After Tracheostomy Placement: Experience with 24-hour Propofol Infusions.

Infants with severe bronchopulmonary dysplasia may require high doses of neurosedative medications to ensure pain control and stability following tracheostomy placement. Subsequent weaning of these medications safely and rapidly is a challenge. We describe a 24-hour propofol infusion to reduce neurosedative medications in 3 high-risk infants following tracheostomy placement.

Safety and tolerability outcomes of nonanesthesiologist-administered propofol using target-controlled infusion in routine GI endoscopy.

BACKGROUND AND AIMS: Nonanesthesiologist-administered propofol (NAAP) is increasingly accepted, but data are limited on drug administration using target-controlled infusion (TCI) in clinical practice. TCI adjusts the drug infusion based on patient-specific parameters, maintaining a constant drug dose to reduce the risk of adverse events (AEs) because of drug overdosing and to enhance patient comfort. The aims of this study were to assess the rate of AEs and to evaluate patient satisfaction with NAAP using TCI in a retrospective cohort of 18,302 procedures. METHODS: Low-risk patients (American Society of Anesthesiologists score I and II) undergoing outpatient GI endoscopic procedures, including EGDs and colonoscopies, were sequentially enrolled at IRCCS San Raffaele Hospital (Milan, Italy) between May 2019 and November 2021. RESULTS: Data from 7162 EGDs and 11,140 colonoscopies were analyzed. Mean patient age was 59.1 ± 14.8 years, and mean body mass index was 24.9 ± 3.7 kg/m2. The male-to-female ratio was equal at 8798 (48.1%):9486 (51.9%). AEs occurred in 240 procedures (1.3%) out of the total cohort, with no differences between EGDs and colonoscopies (100 [1.4%] and 140 [1.2%], respectively; P = .418). Most patients (15,875 [98.9%]) indicated they would likely repeat the procedure with the same sedation protocol. Age (odds ratio, 1.02; 95% confidence interval, 1.01-1.03; P < .008) was the only independent factor associated with overall AEs. CONCLUSIONS: NAAP using TCI is an effective and safe sedation method for routine endoscopy. The proper propofol dosage based on individual patients and the presence of trained operators are crucial for NAAP sedation management.

Characterization of Pediatric Rectal Absorption, Drug Disposition, and Sedation Level for Midazolam Gel Using Physiologically Based Pharmacokinetic/Pharmacodynamic Modeling.

This study aims to explore and characterize the role of pediatric sedation via rectal route. A pediatric physiologically based pharmacokinetic-pharmacodynamic (PBPK/PD) model of midazolam gel was built and validated to support dose selection for pediatric clinical trials. Before developing the rectal PBPK model, an intravenous PBPK model was developed to determine drug disposition, specifically by describing the ontogeny model of the metabolic enzyme. Pediatric rectal absorption was developed based on the rectal PBPK model of adults. The improved Weibull function with permeability, surface area, and fluid volume parameters was used to extrapolate pediatric rectal absorption. A logistic regression model was used to characterize the relationship between the free concentrations of midazolam and the probability of sedation. All models successfully described the PK profiles with absolute average fold error (AAFE) < 2, especially our intravenous PBPK model that extended the predicted age to preterm. The simulation results of the PD model showed that when the free concentrations of midazolam ranged from 3.9 to 18.4 ng/mL, the probability of "Sedation" was greater than that of "Not-sedation" states. Combined with the rectal PBPK model, the recommended sedation doses were in the ranges of 0.44-2.08 mg/kg for children aged 2-3 years, 0.35-1.65 mg/kg for children aged 4-7 years, 0.24-1.27 mg/kg for children aged 8-12 years, and 0.20-1.10 mg/kg for adolescents aged 13-18 years. Overall, this model mechanistically quantified drug disposition and effect of midazolam gel in the pediatric population, accurately predicted the observed clinical data, and simulated the drug exposure for sedation that will inform dose selection for following pediatric clinical trials.

Association between Colonoscopy Sedation Type and Polyp Detection: A Registry-based Cohort Study.

BACKGROUND: Colorectal cancer is a leading cause of cancer-related death. Adenomas and serrated polyps are precursors of colorectal cancer, with serrated polyps being more difficult to detect during colonoscopy. The relationship between propofol use and polyp detection remains unclear. The authors investigated the association of propofol-based versus mild-moderate sedation on adenoma and serrated polyp detection during colonoscopy. METHODS: This retrospective cohort study used observational data from the New Hampshire Colonoscopy Registry. Patients aged greater than 50 yr with screening or surveillance colonoscopies between January 1, 2015, and February 28, 2020, were included. Exclusions were diagnostic examinations, no sedation, missing pathology data, and poor bowel preparation. Multivariate logistic regression was used to evaluate differences in polyp detection between propofol and moderate sedation in the full sample while adjusting for covariates. Propensity score adjustment and clustering at the endoscopist level were used in a restricted sample analysis that included endoscopists and facilities with between 5% and 95% propofol sedation use. RESULTS: A total of 54,063 colonoscopies were analyzed in the full sample and 18,998 in the restricted sample. Serrated polyp prevalence was significantly higher using propofol (9,957 of 29,312; 34.0% [95% CI, 33.4 to 34.5%]) versus moderate sedation (6,066 of 24,751; 24.5% [95% CI, 24.0 to 25.1%]) in the full sample and restricted samples (1,410 of 4,661; 30.3% [95% CI, 28.9 to 31.6%] vs. 3,690 of 14,337; 25.7% [95% CI, 25.0 to 26.5%]). In the full sample multivariate logistic regression, propofol was associated with higher neoplasm (adjusted odds ratio, 1.25 [95% CI, 1.21 to 1.29]), adenoma (odds ratio, 1.07 [95% CI, 1.03 to 1.11]), and serrated polyp detection (odds ratio, 1.51 [95% CI, 1.46 to 1.57]). In the restricted sample using inverse probability of treatment weighted propensity score adjustment and clustering at the endoscopist level, an attenuated but statistically significant effect size was observed for serrated polyps (odds ratio, 1.13 [95% CI, 1.07 to 1.19]), but not for adenomas (odds ratio, 1.00 [95% CI, 0.95 to 1.05]) or any neoplastic lesion (odds ratio, 1.03 [95% CI, 0.98 to 1.08]). CONCLUSIONS: Propofol sedation during colonoscopy may be associated with improved detection of serrated polyps, but not adenomas.

The risk of delirium after sedation with propofol or midazolam in intensive care unit patients.

AIM: Knowledge of risk factors may provide strategies to reduce the high burden of delirium in intensive care unit (ICU) patients. We aimed to compare the risk of delirium after deep sedation with propofol versus midazolam in ICU patients. METHODS: In this prospective cohort study, ICU patients who were in an unarousable state for ≥24 h due to continuous sedation with propofol and/or midazolam were included. Patients admitted ≤24 h, those with an acute neurological disorder and those receiving palliative sedation were excluded. ICU patients were assessed daily for delirium during the 7 days following an unarousable state due to continuous sedation. RESULTS: Among 950 included patients, 605 (64%) subjects were delirious during the 7 days after awaking. The proportion of subsequent delirium was higher after midazolam sedation (152/207 [73%] patients) and after both propofol and midazolam sedation (257/377 [68%] patients), compared to propofol sedation only (196/366 [54%] patients). Midazolam sedation (adjusted cause-specific hazard ratio [adj. cause-specific HR] 1.32, 95% confidence interval [CI] 1.05-1.66) and propofol and midazolam sedation (adj. cause-specific HR 1.29, 95% CI 1.06-1.56) were associated with a higher risk of subsequent delirium compared to propofol sedation only. CONCLUSION: This study among sedated ICU patients suggests that, compared to propofol sedation, midazolam sedation is associated with a higher risk of subsequent delirium. This risk seems more apparent in patients with high cumulative midazolam intravenous doses. Our findings underpin the recommendations of the Society of Critical Care Medicine Pain, Agitation/sedation, Delirium, Immobility (rehabilitation/mobilization), and Sleep (disruption) guidelines to use propofol over benzodiazepines for sedation in ICU patients.

Nontraditional approaches to sedation for anterior segment surgery: a narrative review.

PURPOSE OF REVIEW: Surgical and anesthetic technological advancement have made both cataract and noncataract anterior segment surgery significantly less invasive and time-intensive, facilitating the transition of some of these procedures from the operating room under monitored anesthesia care (MAC) to the office-based setting without MAC. This transition has been aided by the popularization of nonintravenous approaches to achieving patient sedation for these procedures. In this review, we discuss the literature surrounding traditional and nontraditional methods of achieving patient sedation for anterior segment surgery. RECENT FINDINGS: Our survey of the literature suggests that nonintravenous (IV) approaches to sedation for these procedures may be just as safe, effective, and satisfactory to patients as traditional IV approaches. SUMMARY: As anterior segment surgery becomes less invasive and less time-intensive, providers considering transitioning their cataract and anterior segment surgery out of the operating room and into the office-based setting without MAC anesthesia should consider the non-IV sedation options outlined in this review to achieve adequate patient sedation and comfort.

Remimazolam versus propofol for sedation in gastrointestinal endoscopic procedures: a systematic review and meta-analysis.

BACKGROUND: Propofol has a favourable efficacy profile in gastrointestinal endoscopic procedures, however adverse events remain frequent. Emerging evidence supports remimazolam use in gastrointestinal endoscopy. This systematic review and meta-analysis compares remimazolam and propofol, both combined with a short-acting opioid, for sedation of adults in gastrointestinal endoscopy. METHODS: We searched MEDLINE, Embase, and Cochrane databases for randomised controlled trials comparing efficacy-, safety-, and satisfaction-related outcomes between remimazolam and propofol, both combined with short-acting opioids, for sedation of adults undergoing gastrointestinal endoscopy. We performed sensitivity analyses, subgroup assessments by type of short-acting opioid used and age range, and meta-regression analysis using mean patient age as a covariate. We used R statistical software for statistical analyses. RESULTS: We included 15 trials (4516 subjects). Remimazolam was associated with a significantly lower sedation success rate (risk ratio [RR] 0.991; 95% confidence interval [CI] 0.984-0.998; high-quality evidence) and a slightly longer induction time (mean difference [MD] 9 s; 95% CI 4-13; moderate-quality evidence), whereas there was no significant difference between the sedatives in other time-related outcomes. Remimazolam was associated with significantly lower rates of respiratory depression (RR 0.41; 95% CI 0.30-0.56; high-quality evidence), hypotension (RR 0.43; 95% CI 0.35-0.51; moderate-quality evidence), hypotension requiring treatment (RR 0.25; 95% CI 0.12-0.52; high-quality evidence), and bradycardia (RR 0.42; 95% CI 0.30-0.58; high-quality evidence). There was no difference in patient (MD 0.41; 95% CI -0.07 to 0.89; moderate-quality evidence) and endoscopist satisfaction (MD -0.31; 95% CI -0.65 to 0.04; high-quality evidence) between both drugs. CONCLUSIONS: Remimazolam has clinically similar efficacy and greater safety when compared with propofol for sedation in gastrointestinal endoscopies.

Prescription Patterns and Predisposing Factors of Benzodiazepine and Z-Hypnotic Use During Pregnancy: A Nationwide Cohort Study.

PURPOSE: The use of benzodiazepines and Z-hypnotics during pregnancy has raised significant concerns in recent years. However, there are limited data that capture the prescription patterns and predisposing factors in use of these drugs, particularly among women who have been long-term users of benzodiazepines and Z-hypnotics before pregnancy. METHODS: This population-based cohort study comprised 2 930 988 pregnancies between 2004 and 2018 in Taiwan. Women who were dispensed benzodiazepines or Z-hypnotics during pregnancy were identified and further stratified into groups based on their status before pregnancy: long-term users (with a supply of more than 180 days within a year), short-term users (with a supply of less than 180 days within a year), and nonusers. Trends in the use of benzodiazepines or Z-hypnotics and concomitant use with antidepressants or opioids were assessed. Logistic regression models were utilized to identify factors associated with use of these drugs during pregnancy, and interrupted time series analyses (ITSA) were employed to evaluate utilization patterns of these drugs across different pregnancy-related periods. RESULTS: The overall prevalence of benzodiazepine and Z-hypnotic use was 3.5% during pregnancy. Among prepregnancy long-term users, an upward trend was observed. The concomitant use of antidepressants or opioids among exposed women increased threefold (from 8.6% to 23.1%) and sixfold (from 0.3% to 1.7%) from 2004 to 2018, respectively. Women with unhealthy lifestyle behaviors, such as alcohol abuse (OR 2.48; 95% CI, 2.02-3.03), drug abuse (OR 10.34; 95% CI, 8.46-12.64), and tobacco use (OR 2.19; 95% CI, 1.96-2.45), as well as those with psychiatric disorders like anxiety (OR 6.99; 95% CI, 6.77-7.22), insomnia (OR 15.99; 95% CI, 15.55-16.45), depression (OR 9.43; 95% CI, 9.07-9.80), and schizophrenia (OR 21.08; 95% CI, 18.76-23.69), and higher healthcare utilization, were more likely to use benzodiazepines or Z-hypnotics during pregnancy. ITSA revealed a sudden decrease in use of benzodiazepines and Z-hypnotics after recognition of pregnancy (level change -0.55 percentage point; 95% CI, -0.59 to -0.51). In contrast, exposures to benzodiazepines and Z-hypnotics increased significantly after delivery (level change 0.12 percentage point; 95% CI, 0.09 to 0.16). CONCLUSIONS: In this cohort study, an increased trend of benzodiazepine and Z-hypnotic use during pregnancy among prepregnancy long-term users, as well as concomitant use with antidepressants or opioids were found. The findings have highlighted the existence of various risk factors associated with the use of these drugs during pregnancy. Utilization patterns varied across different stages of pregnancy, highlighting the need for prescription guidelines and educational services for women using these drugs during pregnancy.

Total intravenous anesthesia with Ketofol in rabbits: a comparison of the effects of constant rate infusion of midazolam, fentanyl or dexmedetomidine.

BACKGROUND: When inhalant anesthetic equipment is not available or during upper airway surgery, intravenous infusion of one or more drugs are commonly used to induce and/or maintain general anesthesia. Total intravenous anesthesia (TIVA) does not require endotracheal intubation, which may be more difficult to achieve in rabbits. A range of different injectable drug combinations have been used as continuous infusion rate in animals. Recently, a combination of ketamine and propofol (ketofol) has been used for TIVA in both human patients and animals. The purpose of this prospective, blinded, randomized, crossover study was to evaluate anesthetic and cardiopulmonary effects of ketofol total intravenous anesthesia (TIVA) in combination with constant rate infusion (CRI) of midazolam, fentanyl or dexmedetomidine in eight New Zealand White rabbits. Following IV induction with ketofol and endotracheal intubation, anesthesia was maintained with ketofol infusion in combination with CRIs of midazolam (loading dose [LD]: 0.3 mg/kg; CRI: 0.3 mg/kg/hr; KPM), fentanyl (LD: 6 µg/kg; CRI: 6 µg/kg/hr; KPF) or dexmedetomidine (LD: 3 µg/kg; CRI: 3 µg/kg/hr; KPD). Rabbits in the control treatment (KPS) were administered the same volume of saline for LD and CRI. Ketofol infusion rate (initially 0.6 mg kg- 1 minute- 1 [0.3 mg kg- 1 minute- 1 of each drug]) was adjusted to suppress the pedal withdrawal reflex. Ketofol dose and physiologic variables were recorded every 5 min. RESULTS: Ketofol induction doses were 14.9 ± 1.8 (KPM), 15.0 ± 1.9 (KPF), 15.5 ± 2.4 (KPD) and 14.7 ± 3.4 (KPS) mg kg- 1 and did not differ among treatments (p > 0.05). Ketofol infusion rate decreased significantly in rabbits in treatments KPM and KPD as compared with saline. Ketofol maintenance dose in rabbits in treatments KPM (1.0 ± 0.1 mg/kg/min) and KPD (1.0 ± 0.1 mg/kg/min) was significantly lower as compared to KPS (1.3 ± 0.1 mg/kg/min) treatment (p < 0.05). Ketofol maintenance dose did not differ significantly between treatments KPF (1.1 ± 0.3 mg/kg/min) and KPS (1.3 ± 0.1 mg/kg/min). Cardiovascular variables remained at clinically acceptable values but ketofol infusion in combination with fentanyl CRI was associated with severe respiratory depression. CONCLUSIONS: At the studied doses, CRIs of midazolam and dexmedetomidine, but not fentanyl, produced ketofol-sparing effect in rabbits. Mechanical ventilation should be considered during ketofol anesthesia, particularly when fentanyl CRI is used.

Comparison of the recovery time of remimazolam besylate and propofol for gastrointestinal endoscopy sedation in elderly patients.

Background: Recovery time is a crucial factor in ensuring the safety and effectiveness of both patients and endoscopy centers. Propofol is often preferred due to its fast onset and minimal side effects. Remimazolam is a new intravenous sedative agent, characterized by its rapid onset of action, quick recovery and organ-independent metabolism. Importantly, its effect can be specifically antagonized by flumazenil. The primary goal of this study is to compare the recovery time of remimazolam besylate and propofol anesthesia during endoscopic procedures in elderly patients. Methods: 60 patients aged 65-95 years who underwent gastrointestinal endoscopy were randomly and equally assigned to two groups: the remimazolam group (Group R) and the propofol group (Group P). The primary measure was the recovery time, defined as the time from discontinuing remimazolam or propofol until reaching an Observer's Assessment of Alertness and Sedation scale (OAA/S) score of 5 (responds readily to name spoken in normal tone). The time required to achieve an OAA/S score of 3 (responds after name spoken loudly or repeatedly along with glazed marked ptosis) was also recorded and compared. Results: The recovery time for Group R (2.6 ± 1.6 min) was significantly shorter than that for Group P (10.8 ± 3.0 min), with a 95% confidence interval (CI): 6.949-9.431 min, p <0.001. Similarly, the time to attain an OAA/S score of 3 was significantly less in Group R (1.6 ± 0.9 min) compared to Group P (9.6 ± 2.6 min), with a 95% CI: 6.930-8.957 min, p <0.001. Conclusion: Our study demonstrated that remimazolam anesthesia combined with flumazenil antagonism causes a shorter recovery time for elderly patients undergoing gastrointestinal endoscopy compared to propofol. Remimazolam followed by flumazenil antagonism provides a promising alternative to propofol for geriatric patients, particularly during gastrointestinal endoscopy.

Comparison emergence of sedation, using dexmedetomidine and remimazolam, in spinal anaesthesia - double blinded randomized controlled trial.

Background: Continuous intravenous infusion of remimazolam may be suitable for sedation in patients undergoing regional anaesthesia. However, there have been no studies comparing remimazolam and dexmedetomidine for this purpose. This study compared emergence from sedation between dexmedetomidine and remimazolam following continuous intravenous infusion in patients undergoing spinal anaesthesia. Methods: This double-blinded, randomised controlled trial assessed the sedative effects of dexmedetomidine and remimazolam. Following spinal anaesthesia, patients were sedated using continuous intravenous infusion of either dexmedetomidine (D group) or remimazolam (R group).The D group received dexmedetomidine administered at 6 mL/kg/h (6 µg/kg/h) for 10 minutes, followed by 1 mL/kg/h (1 µg/kg/h). The R group received remimazolam administered at 6 mL/kg/h (6 mg/kg/h) for 10 minutes, followed by 1 mL/kg/h (1 mg/kg/h). Sedation levels were evaluated using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale. The time to reach MOAA/S ≤ 3 from the start of drug infusion and the time to reach MOAA/S = 5 from the end of infusion were recorded. Hemodynamic parameters and respiratory rate were also monitored. Results: The R group reached MOAA/S ≤ 3 significantly faster than the D group during induction of sedation (4 ± 1 minutes and 11 ± 3 minutes, respectively, p < 0.001). The R group also reached MOAA/S = 5 significantly faster than the D group during emergence from sedation (11 ± 3 minutes and 16 ± 5 minutes, respectively, p < 0.001). Both groups maintained stable hemodynamic parameters and respiratory rate without any significant differences, although the mean heart rate was significantly lower in the D group than in the R group after the start of infusion. Conclusion: Remimazolam demonstrated significantly faster induction of and emergence from sedation compared to dexmedetomidine, with no significant differences in haemodynamics or respiratory depression.

Patient-Reported Quality of Recovery after Sedation for Endoscopy in the Elderly.

INTRODUCTION: Although sedation is critical in minimizing discomforts in patients, conflicting data regarding the safety of sedation among the elderly population exist. This prospective study aimed to compare the quality of recovery (QoR) from gastrointestinal endoscopy performed under sedation between elderly and younger patients. METHODS: We included 177 patients aged 40-64 (group 1, n = 66), 65-79 (group 2, n = 76), and ≥80 (group 3, n = 35) years. QoR was assessed 1 day after the procedure using the quality of recovery 15 (QoR-15) questionnaire, which is a 15-item questionnaire with scores ranging from 0 to 150. Patient demographic, procedural, and sedation data were collected, and neurocognitive function was assessed before and a day after sedation. RESULTS: Groups 1 and 3 differed according to the Mini-Cog test and 3-word memory test performed before the procedure (p < 0.001). QoR-15 scores between groups were not different (139 ± 19 group 1, 141 ± 17 group 2, and 147 ± 26 group 3; p > 0.05). Patients in groups 3 and 2 were administered lower doses of propofol and midazolam than those in group 1. The incidence of oxygen desaturation (SaO2 <90% for >30 s) was lower in groups 1 and 2 than in group 3 (p = 0.01). CONCLUSIONS: As indicated by the QoR-15 questionnaire, the QoR from sedation was not significantly different between the study groups.

Determining the Optimal Dosage of Dexmedetomidine for Smooth Emergence in Older Patients Undergoing Spinal Surgery: A Study of 44 Cases.

BACKGROUND Emergence agitation, or delirium, occurs during early recovery from general anesthesia and involves disorientation, excitation, and uncontrolled physical movements. Dexmedetomidine is an alpha agonist that has sedative, anxiolytic, analgesic, and sympatholytic activities and is used as a continuous infusion to prevent emergence agitation. This study aimed to evaluate patients aged 65 years and older undergoing general anesthesia to determine the 90% effective dose (ED90) of dexmedetomidine continuous intraoperative infusion to prevent emergence agitation. MATERIAL AND METHODS We enrolled 44 patients aged 65 years and older undergoing spinal surgery under general anesthesia. Dexmedetomidine administration commenced 30 minutes before surgery completion, with a predetermined infusion dose (µg/kg/h), without a loading dose. The initial dose was 0.2 µg/kg/h, and subsequent step size was ±0.05 µg/kg/h. We tried to find ED90 of dexmedetomidine using the biased-coin design. Vital signs, extubation quality scores, extubation-related complications, and postoperative outcomes were monitored. RESULTS Dexmedetomidine ED90 for smooth emergence in older patients was 0.34 µg/kg/h. Peri-extubation vital signs remained within 20% of baseline values, without requiring pharmacological intervention. No hypoxia, hypoventilation, or post-extubation agitation occurred. In the recovery room, 1 patient briefly exhibited excitement but quickly calmed. Nine patients initially unresponsive in the recovery room fully awoke and were promptly discharged. CONCLUSIONS For older patients who are vulnerable to adverse effects of anesthetics and opioids, dexmedetomidine enables gentle awakening without adverse vital sign changes, respiratory depression, excessive sedation, or emergence agitation (ED90=0.34 µg/kg/h). Further studies should involve a larger patient cohort, considering diverse medical conditions in older individuals.

Remimazolam for sedation and anesthesia in children: Protocol for a scoping review.

BACKGROUND: Remimazolam, a novel intravenous benzodiazepine recently approved by both the European Medicines Agency and the Food and Drug Agency, holds significant promise in clinical practice. Its pharmacodynamic profile closely mirrors that of midazolam, while its pharmacokinetics properties bear resemblance to remifentanil. Research in adult populations continues to accumulate, but the pediatric studies' pace is not significant. This scoping review aims to methodically scrutinize published studies, clinical trials, observational research, case reports, and pertinent literature to offer a comprehensive insight into the existing understanding of remimazolam in pediatric sedation and anesthesia. The synthesis of gathered evidence will discern lacunae in the literature, direct forthcoming investigations, and enlighten clinical practices. METHODS: The review will adhere to the guidelines outlined by the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) for Scoping Review. A meticulous search strategy will be executed across prominent peer-reviewed databases, with concerted efforts to identify relevant gray literature. All primary investigations involving the administration of remimazolam in pediatric populations will be encompassed within the scope of this review. RESULTS: The encompassed studies will be elucidated through a narrative synopsis, complemented by descriptive statistical analyses of quantitative data where deemed applicable. CONCLUSION: The planned scoping review aims to delineate the existing evidence regarding the utilization of remimazolam in pediatric anesthesia and sedation. It will discern areas of knowledge deficiency, provide guidance for future inquiries, and enhance clinical practices within the field.

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.