The Efficacy and Safety of Remimazolam Tosilate versus Etomidate-Propofol in Elderly Outpatients Undergoing Colonoscopy: A Prospective, Randomized, Single-Blind, Non-Inferiority Trial

Remimazolam for sedation in gastrointestinal endoscopy: A comprehensive review

Worldwide, a majority of routine endoscopic procedures are performed under some form of sedation to maximize patient comfort. Propofol, benzodiazepines and opioids continue to be widely used. However, in recent years, Remimazolam is gaining immense popularity for procedural sedation in gastrointestinal (GI) endoscopy. It is an ultra-short-acting benzodiazepine sedative which was approved by the Food and Drug Administration in July 2020 for use in procedural sedation. Remimazolam has shown a favorable pharmacokinetic and pharmacodynamic profile in terms of its non-specific metabolism by tissue esterase, volume of distribution, total body clearance, and negligible drug-drug interactions. It also has satisfactory efficacy and has achieved high rates of successful sedation in GI endoscopy. Furthermore, studies have demonstrated that the efficacy of Remimazolam is non-inferior to Propofol, which is currently a gold standard for procedural sedation in most parts of the world. However, the use of Propofol is associated with hemodynamic instability and respiratory depression. In contrast, Remimazolam has lower incidence of these adverse effects intra-procedurally and hence, may provide a safer alternative to Propofol in procedural sedation. In this comprehensive narrative review, highlight the pharmacologic characteristics, efficacy, and safety of Remimazolam for procedural sedation. We also discuss the potential of Remimazolam as a suitable alternative and how it can shape the future of procedural sedation in gastroenterology.

ED50 and ED95 of Remimazolam Tosilate Combined with Different Doses of Fentanyl in Elderly Patients for Painless Gastroscopy

Background

The novel short-acting benzodiazepine drug, remimazolam tosilate, has been employed for sedation during endoscopic procedures. The optimal loading dosage of remimazolam tosilate in gastroscopy for elderly patients when co-administered with fentanyl remains unclear. Therefore, the primary objective of our research was to ascertain the median effective dose (ED50) and the 95% effective dose (ED95) of remimazolam tosilate in combination with various fentanyl dosages for elderly patients undergoing painless gastroscopy.

Methods

Seventy-five patients aged ≥65 years and American Society of Anesthesiologists (ASA) class I-III were recruited to undergo elective painless gastroscopy. All patients were randomized assigned to group F1, group F2, and group F3, and were injected intravenously with different doses of fentanyl (0.5 ug/kg, 1 ug/kg, and 1.5 ug/kg) 3 minutes prior to the administration of remimazolam tosilate, respectively. The initial preset dose of remimazolam tosilate was 0.3 mg/kg in group F1, 0.2 mg/kg in group F2, 0.15 mg/kg in group F3. The dose gradient was 0.02 mg/kg per group according to the up-and-down sequential method. Probibt regression model was employed to determine the ED50 and ED95 of remimazolam tosilate.

Results

The ED50 of remimazolam tosilate in group F3 was lower than that in group F1 and F2 (0.095 [0.088-0.108] mg/kg vs 0.162 [0.153-0.171] mg/kg; 0.258 [0.249-0.266] mg/kg, p < 0.05). The ED95 of remimazolam tosilate was 0.272 mg/kg (95% CI: 0.264-0.295 mg/kg) in group F1, 0.175 mg/kg (95% CI: 0.167-0.200 mg/kg) in group F2 and 0.109 mg/kg (95% CI: 0.101-0.135 mg/kg) in group F3. The total dosage of remimazolam tosilate decreased gradually with the increasing of fentanyl (p < 0.001). The frequency of injection pain was higher in group F1 compared to groups F2 and F3 (p < 0.05). The patients in group F3 had a lower incidence of hypotension than in groups F1 and F2 (p < 0.05). There was no respiratory depression, intraoperative consciousness, dizziness or delirium in the three groups.

Conclusion

The concurrent use of fentanyl reduces the dosage of remimazolam tosilate required for sedative gastroscopy in elderly patients in a dose-dependent manner. Moreover, 1.5 ug/kg fentanyl combined with remimazolam tosilate may reduce the incidence of hypotension and injection pain. These findings should be confirmed in a large-scale study.

Efficacy and Safety of Remimazolam Versus Etomidate for Induction of General Anesthesia: Protocol for a Systematic Review and Meta-Analysis

BACKGROUND

Postinduction hypotension (PIHO) is a hemodynamic abnormality commonly observed during the induction of general anesthesia. Etomidate is considered a safer drug for the induction of anesthesia because it has only minor adverse effects on the cardiovascular and pulmonary systems. Recent evidence indicates that the novel benzodiazepine remimazolam has minimal inhibitory effects on the circulation and respiration. However, the efficacy and safety of remimazolam versus etomidate in the induction of anesthesia are unclear.

OBJECTIVE

To further understand the potential of remimazolam in anesthesia induction, it is necessary to design a meta-analysis to compare its effects versus the classic safe anesthetic etomidate. The aim of this study is to determine which drug has more stable hemodynamics and a lower incidence of PIHO. Our study will also yield data on sedation efficiency, time to loss of consciousness, time to awakening, incidence of injection pain, and postoperative nausea and vomiting with the two drugs.

METHODS

We plan to search the Web of Science, Cochrane Library, Embase, PubMed, China National Knowledge Infrastructure, and Wanfang databases from the date of their creation until March 31, 2025. The language is limited to English and Chinese. The search terms are "randomized controlled trials," "etomidate," and "remimazolam." The incidence of PIHO is the primary outcome measure. Secondary outcomes include depth of anesthesia after induction, sedation success rate, time to loss of consciousness, hemodynamic profiles, recovery time, incidence of injection pain, and postoperative nausea and vomiting. Reviews, meta-analyses, case studies, abstracts from conferences, and commentaries will not be included. The heterogeneity of the results will be evaluated by sensitivity and subgroup analyses. RevMan software and Stata software will be used for data analysis. We will evaluate the quality of included studies using version 2 of the Cochrane risk-of-bias tool. The confidence of the evidence will be assessed through the Grading of Recommendations, Assessments, Developments, and Evaluations system.

RESULTS

The protocol was registered in the international PROSPERO (Prospective Register of Systematic Reviews) registry in November 2023. As of June 2024, we have performed a preliminary article search and retrieval for further review. The review and analyses are expected to be completed in March 2025. We expect to submit manuscripts for peer review by the end of June 2025.

CONCLUSIONS

By synthesizing the available evidence and comparing remimazolam and etomidate, we hope to provide valuable insights into the selection of anesthesia-inducing drugs to reduce the incidence of PIHO and improve patient prognosis.

TRIAL REGISTRATION

PROSPERO CRD42023463120; https://tinyurl.com/333jb8bm.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/55948.

Comparative observation of the effectiveness and safety of remimazolam besylate versus dexmedetomidine in gastrointestinal surgery in obese patients

BACKGROUND

Surgery for obese patients carries a higher risk of anesthesia complications compared with surgery for nonobese patients. Thus, a safe and effective anesthesia strategy is necessary to improve the medical experience of such patients and ensure their safety.

AIM

To compared the effectiveness and safety of remimazolam besylate versus dexmedetomidine (DEX) in gastrointestinal surgery in obese patients.

METHODS

The study cohort included 60 obese patients undergoing gastrointestinal surgery between July 2021 and April 2023, comprising 30 patients who received DEX intervention (control group) and 30 patients who received remimazolam besylate intervention (research group). Heart rate (HR), respiratory rate (RR), mean arterial pressure (MAP), blood oxygen saturation (SpO2), safety (nausea and vomiting, bradycardia, hypotension, and apnea), anesthesia and examination indices [induction time, anesthesia recovery time, and postanesthesia care unit (PACU) discharge time], sedation effect (Ramsay Sedation Scale), and postoperative pain visual analog scale were comparatively analyzed before anesthesia (T0), during anesthesia (T1), and after anesthesia (T2).

RESULTS

At T1, the research group showed significantly smaller changes in HR, RR, MAP, and SpO2 than the control group, with a significantly lower adverse reaction rate and shorter induction, anesthesia recovery, and PACU discharge times. Additionally, the intra- and postoperative Ramsay Sedation Scale scores were statistically higher in the research group than in the control group.

CONCLUSION

Remimazolam besylate was significantly more effective than DEX in gastrointestinal surgery in obese patients and had a higher safety profile and value in clinical promotion.

Adverse Drug Events Observed with the Newly Approved Remimazolam in Comparison to Propofol for General Anesthesia in Patients Undergoing Surgery: A Meta-analysis

INTRODUCTION

Developments in anesthetic pharmacology have been aiming at minimizing physiological disturbance in addition to maintaining and improving titrateability, recovery profile, and patient experience. Remimazolam, a GABAAlpha receptor agonist, is a new intravenous anesthetic agent which has recently been approved for use. This analysis aimed to systematically compare the adverse drug events reported with the newly approved remimazolam in comparison to propofol for general anesthesia (GA) in patients undergoing surgery.

METHODS

Electronic databases were searched from 15 May to 20 December 2023 for relevant publications which compared the outcomes reported with the newly approved remimazolam versus propofol in patients undergoing surgery. Relevant reported adverse drug events were the endpoints of this study. The statistical analysis was carried out using the latest version of the RevMan software. Data analysis was represented by risk ratio (RR) with 95% confidence intervals (CI).

RESULTS

Sixteen studies with a total number of 1897 participants were included in this analysis; 1104 participants received remimazolam and 793 participants received propofol. The risks for hypotension (RR 0.50, 95% CI 0.43-0.58; P = 0.00001), hypoxemia (RR 0.43, 95% CI 0.19-0.99; P = 0.05), bradycardia (RR 0.53, 95% CI 0.36-0.78; P = 0.001), pain at injection site (RR 0.07, 95% CI 0.01-0.56; P = 0.01), and total adverse events (RR 0.33, 95% CI 0.24-0.47; P = 0.00001) were significantly lower with remimazolam. However, no significant differences were observed in terms of postoperative nausea and vomiting (RR 0.98, 95% CI 0.66-1.46; P = 0.93), dizziness (RR 0.42, 95% CI 0.11-1.57; P = 0.20), psychiatric symptoms (RR 1.09, 95% CI 0.45-2.67; P = 0.85), and respiratory depression (RR 0.81, 95% CI 0.24-2.76; P = 0.74).

CONCLUSION

Our current analysis showed that the newly approved remimazolam was apparently associated with significantly fewer adverse drug events in comparison to propofol for GA in patients undergoing surgery. Therefore, this new drug should be further studied and more research with larger population sizes should be carried out to confirm this hypothesis.

Effectiveness and safety of remimazolam combined with alfentanil in hysteroscopic examination: A prospective, randomized, single-blind trial

BACKGROUND

Remimazolam is a novel, ultrashort-acting benzodiazepine. This study aimed to compare the efficacy and safety of remimazolam and propofol for hysteroscopic examination, to determine the optimal dose of remimazolam combined with alfentanil for painless hysteroscopy, and to calculate its median effective dose (ED50).

METHODS

Step 1: A total of 208 patients undergoing hysteroscopic examination were prospectively included in this study. Patients were randomized into 4 groups: 0.2 mg/kg remimazolam (group A), 0.25 mg/kg remimazolam besylate (group B), 0.3 mg/kg remimazolam (group C), and 2 mg/kg propofol (group D), with 52 patients in each group. One minute after losing consciousness, patients received an intravenous injection of alfentanil at 5 µg/kg, followed by a continuous infusion of alfentanil at 0.5 µg/kg/min. If patients showed frowning, movement, or MOAA/S > 1, sedatives were added: 0.05 mg/kg/dose of remimazolam for groups A, B, and C, and 0.5 mg/kg/dose of propofol for group D. Step 2: Dixon's up-and-down method was used to calculate the ED50 of remimazolam combined with alfentanil during hysteroscopic examination.

MAIN RESULTS

The sedation success rates of the remimazolam groups were 88.46%, 94.23%, and 98.08%, respectively, compared to 96.15% in the propofol group, with no significant difference (P = .175). MAP in groups A and B was higher than in group D (P < .05), and significantly higher in group C than in group D (P = .0016). SpO2 values in groups A, B, and C were higher than in group D at T2 to T3 (P < .001). HR in groups A, B, and C was significantly higher than in group D (P < .001). The ED50 of remimazolam combined with alfentanil in hysteroscopy was 0.244 mg/kg, 95%CI (0.195-0.22) and ED95 was 0.282 mg/kg, 95%CI (0.261-1.619).

CONCLUSION

In hysteroscopy, the sedative effect of remimazolam is like that of propofol, with 0.25 mg/kg remimazolam showing better safety and efficacy, and less impact on the respiratory and circulatory systems. Additionally, under the influence of alfentanil, the ED50 of remimazolam in hysteroscopy is 0.244 mg/kg, with no severe adverse reactions observed.

Comparison of efficacy and safety of equivalent doses of remimazolam versus propofol for gastroscopy anesthesia in elderly patients

Remimazolam, a novel intravenous anesthetic, has been proven to be safe and efficacious in the gastroscopy setting among the elderly. However, reports comparing the effectiveness and safety of using equivalent doses of remimazolam with propofol have not been seen. The aim of this study was to compare the sedation efficacy and safety of the 95% effective doses (ED95) of remimazolam versus propofol combined with sufentanil in the gastroscopy setting among the elderly. In the first step of this two-step study, a modified up-and-down method was used to calculate the ED95 of remimazolam and propofol when combined with 0.1 µg/kg sufentanil in inhibiting body movement of elderly patients undergoing gastroscopy. In the second step, ED95 of both agents calculated in the first step were administered, endpoints of efficacy, safety, and incidence of adverse events were compared. A total of 46 individuals completed the first step. The ED95 of remimazolam was 0.163 mg/kg (95% CI 0.160-0.170 mg/kg), and that of propofol was 1.042 mg/kg (95% CI 1.007-1.112 mg/kg). In the second step, 240 patients completed the trial. The anesthetic effective rates of the remimazolam group and the propofol group were 78% and 83%, respectively, with no statistical difference (P = 0.312). Patients in the remimazolam group had more stable circulatory functions (P < 0.0001) and a lower incidence of pain on injection (3.3% vs. 19.5%, P < 0.0001). The incidence of hypotension was low in the remimazolam versus propofol group (15.6% vs. 39.0%, P < 0.0001). Overall adverse event was low in the remimazolam versus propofol group (21.3% vs. 62.7%, P < 0.0001).In this study, we found that when anesthesia was administered to elderly gastroscopy patients based on 95% effective doses of remimazolam and propofol, remimazolam was as effective as propofol, but was safer with a lower incidence of adverse events.Study registration: Chinese Clinical Trial Registry, ChiCTR2000034234. Registered 29/06/2020, https://www.chictr.org.cn .

Remimazolam versus propofol for sedation in gastrointestinal endoscopy and colonoscopy within elderly patients: a meta-analysis of randomized controlled trials

PURPOSE

Propofol has become the sedative of choice for endoscopy and colonoscopy. However, it has shown associations with various adverse effects, specifically in the geriatric population. In contrast, remimazolam is a novel benzodiazepine, demonstrating a superior clinical safety profile. Hence, this systematic review and meta-analysis aims to clarify the efficacy and safety of remimazolam versus propofol in elderly patients (≥ 60 years) undergoing gastrointestinal endoscopic and colonoscopy procedures.

METHODS

Electronic databases including PubMed, Cochrane Library, ScienceDirect, and Google Scholar were explored from inception till January 7, 2024. The Cochrane Risk of Bias Tool for Randomized Controlled Trials (RoB-2) was utilized to evaluate the quality of each included study reported in this meta-analysis.

RESULTS

Seven randomized control trials were included, resulting in the pooling of 1,466 patients (remimazolam: 731 patients; propofol: 735 patients). Propofol demonstrated a significantly lower time to loss of consciousness (P < 0.00001, 4 studies, 784 patients) and a greater sedation success after first dose (P = 0.05, 5 studies, 1,271 patients). Remimazolam reported a significantly lower risk of bradycardia (P = 0.02, 5 studies, 1,323 patients), hypoxemia (P < 0.00001, 6 studies, 1,389 patients), and pain on injection site (P < 0.00001, 5 studies, 1,184 patients). No statistically significant differences in sedation time, number of supplemental doses, procedural parameters, and other adverse outcomes were reported.

CONCLUSION

As per the results of our analyses, propofol demonstrated comparatively superior efficacy, however, remimazolam demonstrated comparatively superior safety. The debatable evidence generated from this meta-analysis may not currently be powerful enough to advocate for the use of remimazolam in elderly patients undergoing gastrointestinal procedures; hence, further comprehensive studies are necessary in order to arrive at a robust conclusion.

Safety and efficacy comparison of remimazolam and propofol for intravenous anesthesia during gastroenteroscopic surgery of older patients: A meta-analysis

BACKGROUND

Remimazolam is characterized by rapid action and inactive metabolites. It is used as the general anesthetic for many clinical surgeries. In this study, we performed a meta-analysis to evaluate whether remimazolam is superior to propofol for gastroenteroscopy in older patients.

AIM

To compare the adverse events and efficacy of remimazolam and propofol during gastroenteroscopy in older adults.

METHODS

The PubMed, Web of Science, the Cochrane Library databases were queried for the relevant key words "remimazolam," "and propofol," "and gastrointestinal endoscopy or gastroscopy." The search scope was "Title and Abstract," and the search was limited to human studies and publications in English. Seven studies wherein remimazolam and propofol were compared were included for the meta-analysis.

RESULTS

We selected seven randomized controlled trials involving 1445 cases for the analysis. Remimazolam reduced the hypotension (relative risk, RR = 0.44, 95%CI: 0.29-0.66, P = 0.000), respiratory depression (RR = 0.46, 95%CI: 0.30-0.70, P = 0.000), injection pain (RR = 0.12, 95%CI: 0.05-0.25, P = 0.000), bradycardia (RR = 0.37, 95%CI: 0.24-0.58, P = 0.000), and time to discharge [weighted mean difference (WMD) = -0.58, 95%CI: -0.97 to -0.18, P = 0.005], compared to those after propofol administration. No obvious differences were observed for postoperative nausea and vomiting (RR = 1.09, 95%CI: 0.97-1.24, P = 0.151), dizziness (RR = 0.77, 95%CI: 0.43-1.36, P = 0.361), successful sedation rate (RR = 0.96, 95%CI: 0.93-1.00, P = 0.083), or the time to become fully alert (WMD = 0.00, 95%CI: -1.08-1.08, P = 0.998).

CONCLUSION

Remimazolam appears to be safer than propofol for gastroenteroscopy in older adults. However, further studies are required to confirm these findings.

Remimazolam Dosing for Gastroscopy: A Randomized Noninferiority Trial

BACKGROUND

Remimazolam, an ultra-short-acting benzodiazepine, may provide adequate sedation for endoscopy while causing less cardiovascular or respiratory disturbance than propofol. Although fixed-dose administration is suggested, body weight affects the volume of the central chamber and thus affects the sedation depth that can be achieved by the first dose. This study aimed to compare the efficacy and safety of different doses of remimazolam and propofol by body weight for sedation during gastroscopy.

METHODS

This multicenter, randomized, single-blind, parallel-controlled noninferiority trial recruited patients from five centers between March 2021 and July 2022. A total of 1,883 patients scheduled to undergo gastroscopy were randomized to groups receiving 0.15 mg/kg remimazolam, 0.2 mg/kg remimazolam, or 1.5 mg/kg propofol. The noninferiority margin was set to 5%. The primary outcome was the success rate of sedation. Adverse events were recorded to evaluate safety.

RESULTS

The sedation success rate of the 0.2 mg/kg remimazolam group was not inferior to that of the 1.5 mg/kg propofol group (98.7% vs. 99.4%; risk difference, -0.64%; 97.5% CI, -2.2 to 0.7%, meeting criteria for noninferiority). However, the sedation success rate of the 0.15 mg/kg remimazolam group was 88.5%, and that of the 1.5 mg/kg propofol group was 99.4% (risk difference, -10.8%; 97.5% CI, -14.0% to -8.0%), demonstrating inferiority. Simultaneously, the overall adverse events rate of remimazolam was lower than that of propofol, and the incidence of bradycardia, hypotension, subclinical respiratory depression, and hypoxia in the remimazolam groups was significantly lower than that in the propofol group.

CONCLUSIONS

This trial established the noninferior sedation success rate of remimazolam (0.2 mg/kg but not 0.15 mg/kg) compared with propofol (1.5 mg/kg), with a superior safety profile.

EDITOR’S PERSPECTIVE

Safety and effcacy of remimazolam tosilate for sedation during combined spinal-epidural anesthesia for orthopedic procedures: a randomized controlled trial

OBJECTIVE

The objective of this study was to assess the efficacy and safety of Remimazolam in the context of combined spinal-epidural anesthesia for sedation during orthopedic surgery.

METHODS

This randomized controlled trial enrolled patients scheduled for orthopedic surgery under combined spinal-epidural anesthesia (N = 80), who were randomly allocated to receive either dexmedetomidine (Group-D) or remimazolam (Group-R). The target sedation range aimed for a Ramsay score of 2-5 or a BIS value of 60-80 to evaluate the effectiveness and safety of remimazolam during sedation.

RESULTS

The time taken to achieve the desired level of sedation was significantly shorter in the remimazolam group compared to the dexmedetomidine group (3.69 ± 0.75 vs. 9.59 ± 1.03; P < 0.0001). Patients in the remimazolam group exhibited quicker recovery, fewer intraoperative adverse events, more consistent vital signs, and greater satisfaction at various time points throughout the surgery.

CONCLUSION

This preliminary study demonstrates that remimazolam tosilate serves as a safe and effective sedative for orthopedic surgery performed under combined spinal-epidural anesthesia, in comparison with dexmedetomidine.

Comparison of remimazolam and propofol combined with low dose esketamine for pediatric same-day painless bidirectional endoscopy: a randomized, controlled clinical trial

Background: Remimazolam has shown similar or even superior properties to propofol in procedural sedation in adults, but few studies have been conducted in pediatric populations. Thus, we aimed to compare the effect and safety of remimazolam and propofol combined with low dose esketamine for pediatric same-day bidirectional endoscopy (BDE). Methods: Pediatrics <18 years scheduled for elective BDE under sedation were included and randomly assigned to remimazolam group (R group) or propofol group (P group). The primary outcome was the success rate of sedation. Secondary outcomes include sedation-related information and adverse events. Mean arterial pressure (MAP), heart rate (HR), and perfusion index (PI) were recorded during sedation. Results: A total of 106 patients were enrolled and analyzed. The success rate of sedation was 100% in both groups. Compared with the P group, the induction time of the R group was significantly prolonged (p < 0.001), and the incidence of injection pain, intraoperative respiratory depression, hypotension and bradycardia was significantly lower (p < 0.001). The changes in MAP, HR and PI were relatively stable in the R group compared with the P group. Additionally, awake time significantly decreased with age by approximately 1.12 index points for each increase in age in the P group (p = 0.002) but not in the R group (p > 0.05). Furthermore, the decline in PI and PI ratio during BDE was related to body movement in the P group. Conclusion: Remimazolam combined with low dose esketamine has a non-inferior sedative effect than propofol for pediatric BDE, with no injection pain, less respiratory depression, more stable hemodynamics. Moreover, early detection of the decline in PI may avoid harmful stimulation under light anesthesia. Clinical trial registration: https://www.clinicaltrials.gov/study/NCT05686863?id=NCT05686863&rank=1, NCT05686863.

The safety of remimazolam versus propofol in gastroscopic sedation: a meta-analysis

BACKGROUND

This meta-analysis was designed to compare the safety and efficiency of remimazolam with those of propofol in patients undergoing gastroscope sedation.

METHODS

We searched PubMed, Cochrane Library, Embase, Ovid, Wanfang Database, China National Knowledge Infrastructure, SINOMED, and ClinicalTrials.gov for studies that reported on remimazolam versus propofol for gastroscope sedation from establishment to February 25, 2023. The sedative efficiency and the incidence of adverse events were assessed as outcomes. Version 2 of the Cochrane risk-of-bias assessment tool was used to assess the risk of bias. Review Manager 5.4 and STATA 17 were used to perform all statistical analyses.

RESULTS

A total of 26 randomized controlled trials involving 3,641 patients were included in this meta-analysis. The results showed that remimazolam had a significantly lower incidence of respiratory depression (risk ratio [RR] = 0.40, 95% confidence interval [CI]: 0.28-0.57; p < 0.01, GRADE high), hypoxemia (RR = 0.34, 95% CI: 0.23-0.49; p < 0.01, GRADE high), bradycardia (RR = 0.34, 95% CI: 0.23-0.51; p < 0.01, GRADE high), dizziness (RR = 0.45, 95% CI: 0.31-0.65; p < 0.01, GRADE high), injection site pain (RR = 0.06, 95% CI: 0.03-0.13; p < 0.01, GRADE high), nausea or vomiting (RR = 0.79, 95% CI: 0.62-1.00; p = 0.05, GRADE moderate), and hypotension (RR = 0.36, 95% CI: 0.26-0.48; p < 0.01, GRADE low).

CONCLUSIONS

Remimazolam can be used safely in gastroscopic sedation and reduces the incidence of respiratory depression, hypoxemia, bradycardia, injection site pain, and dizziness compared with propofol, and doesn't increase the incidence of nausea and vomiting.

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

BACKGROUND

Dreaming sometimes occurs during sedation. It has been reported that factors such as different anesthetics, depth of anesthesia, age, sex, and preoperative psychological state may affect dreams. Ciprofol and remimazolam are novel choices for painless endoscopy. Herein, we aimed to investigate dreaming during gastrointestinal endoscopy under propofol, ciprofol, and remimazolam anesthesia respectively.

METHODS

This is a prospective, parallel-design double-blind, single-center clinical trial. Three hundred and sixty subjects undergoing elective painless gastroscopy, colonoscopy, or gastroenteroscopy will be enrolled. Eligible subjects will undergo propofol-, ciprofol-, or remimazolam-induced anesthesia to finish the examination. Interviews about the modified Brice questionnaire will be conducted in the recovery room. Incidence of dreaming is set as the primary outcome. Secondary outcomes include type of dreams, improvement of sleep quality, evaluation of patients, incidence of insufficient anesthesia, and intraoperative awareness. Safety outcomes are the incidences of hypotension and hypoxia during examination and adverse events during recovery.

DISCUSSION

This study may observe different incidences of dreaming and diverse types of dreams, which might lead to different evaluations to the anesthesia procedure. Based on the coming results, anesthesiologists can make a better medication plan for patients who are going to undergo painless diagnosis and treatment.

TRIAL REGISTRATION

This trial was registered at the Chinese Clinical Trial Registry on May 18, 2023 (registration number ChiCTR2300071565).

The effective dose of remimazolam in adult gastroscopy

OBJECTIVES

The objectives of this study were to explore the median effective dose (ED50) and the dose required for successful anesthesia in 95% of the patients (ED95) of remimazolam for intravenous anesthesia in adult outpatients undergoing gastroscopy.

METHODS

This pilot study was conducted in patients scheduled to undergo painless gastroscopy at the authors' hospital between March 15, 2022 and March 25, 2022. The ED of remimazolam was determined using the modified Dixon sequential method, using an initial induction dose of 0.2 mg/kg. With successful or failed anesthesia, the remimazolam dose was decreased or increased by 0.05 mg/kg for the next patient, respectively.

RESULTS

Twenty-two patients (43.6 ± 10.5 years of age) were enrolled. During gastroscopy, the remimazolam induction dose was 19.93 ± 2.96 mg (0.2-0.45 mg/kg). Eighteen patients could complete anesthesia with remimazolam alone, and four patients needed propofol to complete anesthesia. The induction time after the injection of remimazolam was 20.8 ± 8.4 s, the gastroscopy time was 5.1 ± 1.3 min, and the anesthesia recovery time was 17.5 ± 5.6 min. The ED50 and the ED95 of remimazolam were 0.362 mg/kg (95% confidence interval [CI]: 0.313-0.455 mg/kg) and 0.464 mg/kg (95% CI: 0.403-2.242 mg/kg), respectively. The vital signs of all patients remained within the predefined acceptable limits. No patients required antagonist rescue.

CONCLUSION

The ED50 and ED95 of remimazolam for adult gastroscopy were 0.362 mg/kg and 0.464 mg/kg, respectively. Additional anesthetics might be required during gastroscopy in some patients.

TRIAL REGISTRATION

The trial was registered. The number is ChiCTR2200057446.

Remimazolam and serious adverse events: A scoping review

Remimazolam is anticipated to be an interesting anaesthetic and sedative. It combines the pharmacodynamic properties of midazolam with pharmacokinetic properties similar to remifentanil. However, worrisome case reports of anaphylaxis, delayed emergence and re-sedation have emerged recently and necessitate further investigation.PubMed (including MEDLINE) and EMBASE were searched for all studies reporting serious adverse events where remimazolam was administered for sedation or anaesthesia.Thirty-six case reports and 73 trials were identified, involving a total of 6740 patients who received remimazolam. Hypotension was reported in 911 cases, delayed emergence in 68 cases, anaphylaxis in 10 cases and re-sedation in 8 cases. The incidence of hypotension seems to be lower compared with other anaesthetics, even in high-risk patients.Delayed emergence might be related to the metabolism of remimazolam through carboxylesterase 1 (CES1), a tissue esterase predominant in the liver. There is significant interindividual variation, and it is inhibited by flavonoids, fatty acids and alcohol. Individual benzodiazepine sensitivity has also been reported. A higher BMI, older age and low plasma albumin concentration are risk factors for delayed emergence. Anaphylaxis might be related to a non-IgE-mediated effect of the excipient dextran-40 or a partially IgE-mediated reaction to remimazolam itself. Resedation has been reported after flumazenil reversal and is explained by the specific pharmacokinetic properties of flumazenil and remimazolam. Reversal by flumazenil should be reserved for and used carefully in patients with delayed emergence.

VISUAL ABSTRACT

http://links.lww.com/EJA/A864 .

Efficacy and safety of remimazolam besilate for sedation in outpatients undergoing impacted third molar extraction: a prospective exploratory study

BACKGROUND

Dental treatments often cause anxiety, fear, and stress in patients. Intravenous sedation is widely used to alleviate these concerns, and various agents are employed for sedation. However, it is important to find safer and more effective sedation agents, considering the adverse effects associated with current agents. This study aimed to investigate the efficacy and safety of remimazolam besilate (hereinafter called "remimazolam") and to determine the optimal dosages for sedation in outpatients undergoing dental procedures.

METHODS

Thirty-one outpatients aged 18-65 years scheduled for impacted third molar extraction were included in the study. Remimazolam was administered as a single dose of 0.05 mg/kg followed by a continuous infusion at a rate of 0.35 mg/kg/h, with the infusion rate adjusted to maintain a sedation level at a Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score of 2-4. The primary endpoint was the sedation success rate with remimazolam monotherapy, and the secondary endpoints included induction time, recovery time, time until discharge, remimazolam dose, respiratory and circulatory dynamics, and frequency of adverse events.

RESULTS

The sedation success rate with remimazolam monotherapy was 100%. The remimazolam induction dose was 0.08 (0.07-0.09) mg/kg, and the anesthesia induction time was 3.2 (2.6-3.9) min. The mean infusion rate of remimazolam during the procedure was 0.40 (0.38-0.42) mg/kg/h. The time from the end of remimazolam administration to awakening was 8.0 (6.7-9.3) min, and the time from the end of remimazolam administration to discharge was 14.0 (12.5-15.5) min. There were no significant respiratory or circulatory effects requiring intervention during sedation.

CONCLUSIONS

Continuous intravenous administration of remimazolam can achieve optimal sedation levels without significantly affecting respiratory or circulatory dynamics. The study also provided guidance on the appropriate dosage of remimazolam for achieving moderate sedation during dental procedures. Additionally, the study findings suggest that electroencephalogram monitoring can be a reliable indicator of the level of sedation during dental procedural sedation with remimazolam.

TRIAL REGISTRATION

The study was registered in the Japan Registry of Clinical Trials (No. jRCTs061220052) on 30/08/2022.

Remimazolam vs Etomidate: Haemodynamic Effects in Hypertensive Elderly Patients Undergoing Non-Cardiac Surgery

Background

Remimazolam tosilate (RT) is a novel ultrashort-acting γ-aminobutyric acid subtype A (GABAA) agonist, with several advantages including rapid induction and recovery, stable haemodynamics, and mild respiratory inhibition. However, studies have not been conducted to explore the haemodynamic effects of RT in elderly hypertensive subjects undergoing non-cardiac surgery. Therefore, we sought to compare the effects of anaesthesia induction using different doses of RT and etomidate on the haemodynamics of this group of patients.

Methods

Patients were recruited into this single-center, prospective, randomized, double-blind trial from October 2022 to June 2023. A total of 150 hypertensive elderly undergoing non-cardiac surgery were randomly assigned into 0.2 mg/kg RT group (Group RL), 0.3 mg/kg RT group (Group RH) and 0.3 mg/kg etomidate group (Group E). The primary outcome of the study was haemodynamic changes (mean arterial pressure fluctuation value -∆MAP and heart rate fluctuation value -∆HR) observed during anaesthesia induction. Secondary outcomes included incidence of adverse cardiovascular events and adverse drug reactions (injection pain and myoclonus), cumulative doses of vasoactive drugs and vital signs at different time points.

Results

Patients in Group E and Group RL had significantly lower haemodynamic fluctuations (∆MAP), lower incidence of hypotension and cumulative dose of ephedrine than subjects in Group RH. Patients in groups RL and RH had significantly lower incidence of injection pain and myoclonus compared with patients in group E. The results showed no statistically significant differences in ∆HR, hypertension, bradycardia, tachycardia, and time to loss of eye-opening reflex and start of intubation, and vital signs at different time points among the three groups.

Conclusion

Use of low-dose RT (0.2 mg/kg) for induction of non-cardiac surgical anaesthesia in elderly hypertensive patients is more effective in maintaining haemodynamic stability and has fewer adverse effects compared with etomidate.

Effects of remimazolam combined with sufentanil on hemodynamics during anesthetic induction in elderly patients with mild hypertension undergoing orthopedic surgery of the lower limbs: a randomized controlled trial

BACKGROUND

This randomized controlled trial was performed to observe the effect of remimazolam with sufentanil on hemodynamics during anesthetic induction in elderly patients with mild hypertension undergoing orthopedic surgery of the lower limbs.

METHODS

Sixty elderly patients were randomly assigned to undergo general anesthesia with intravenous injection of either remimazolam besylate (25 mg/vial, batch number 10T11011; Yichang Humanwell Pharmaceutical Co., Ltd., Yichang, China) at 0.2 mg/kg (Group R, n = 30) or propofol at 1.5 mg/kg (Group P, n = 30). Both injections were completed within 15 to 20 s. If the bispectral index value did not reach 40 to 60, then 0.05 mg/kg of remimazolam was added in Group P and 1 mg/kg of propofol was added in Group R. When the BIS value reached 40 to 60, sufentanil was administered at 0.3 to 0.5 µg/kg and cisatracurium was administered at 0.15 to 0.2 mg/kg in both groups. Three minutes later, tracheal intubation and controlled ventilation were performed to maintain the end-tidal carbon dioxide partial pressure at 4.5 to 5.0 kPa. The mean arterial pressure (MAP), heart rate (HR), cardiac output (CO), continuous cardiac index (CI), systemic vascular resistance (SVR), and pulse oxygen saturation were recorded before induction (T0), when the eyelash reflex disappeared (T1), immediately after endotracheal intubation (T2), 1 min after endotracheal intubation (T3), and 5 min after endotracheal intubation (T4). The disappearance time of the eyelash reflex, injection pain, hypotension, bradycardia, hiccupping, nausea and vomiting, and other adverse events were observed.

RESULTS

The MAP, HR, CO, and CI at T1, T2, T3, and T4 were significantly higher in Group R than P, while SVR was significantly lower in Group R than P (P < 0.05). In Group P, the MAP, HR, CO, and CI were significantly lower and the SVR was significantly higher at T1, T2, T3, and T4 than at T0 (P < 0.05). Adverse events occurred in 8 (20%) patients in Group R and 22 (73%) in Group P. The total incidence of adverse events was significantly lower in Group R than P (P < 0 0.001).

CONCLUSION

Remimazolam combined with sufentanil for general anesthesia induction has the advantages of small hemodynamic fluctuations, stable circulation, and few adverse reactions, making it suitable for elderly patients with mild hypertension.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2300069224, 10/03/2023).

Effects of Remimazolam Anesthesia with Two Induction Doses on Hemodynamics and Recovery Profile in Older Patients: Comparison with Propofol Anesthesia

Remimazolam has advantages such as hemodynamic stability and rapid onset. We investigated the effects of induction doses on hemodynamics and recovery profiles for remimazolam compared to propofol in older patients. Sixty-nine patients aged >65 years were randomly assigned to either the propofol anesthesia group (P group) or the remimazolam anesthesia group with an induction dose of 6 mg/kg/h (R6 group) or 12 mg/kg/h (R12 group), followed by 1 mg/kg/h. P group was anesthetized with 4 µg/mL of propofol effect-site concentration (Ce) with target-control infusion, followed by 2.5-3 µg/mL of Ce. The primary outcome was the difference between the baseline mean arterial pressure (MAP) and the lowest MAP during anesthesia (ΔMAP). ΔMAP was comparable between the P, R6, and R12 groups (43.8 ± 13.8 mmHg, 39.2 ± 14.3 mmHg, and 39.2 ± 13.5 mmHg, p = 0.443). However, the frequencies of vasoactive drug use were 54.5%, 17.4%, and 30.4% (p = 0.029), and the median doses of ephedrine 3 (0-6) mg, 0 (0-0) mg, and 0 (0-0) mg (p = 0.034), which were significantly different. This study showed remimazolam anesthesia with an induction dose of 6 mg/kg/h, rather than 12 mg/kg/h, could reduce the requirement for vasoactive drugs compared to propofol anesthesia.

Determination of the 95% effective dose of remimazolam tosylate in anesthesia induction inhibits endotracheal intubation response in senile patients

Background and Purpose: The prevalence of elderly patients prompts anesthesiologists to determine the optimal dose of medication due to the altered pharmacokinetics and pharmacodynamics of this population. The present study aimed to determine the 95% effective dose (ED₉₅) of remimazolam tosylate in anesthesia induction to inhibit endotracheal intubation-related cardiovascular reaction in frail and non-frail senile patients. Methods: A prospective sequential allocation dose-finding study of remimazolam tosylate was conducted on 80 elderly patients who received general anesthesia between May and June 2022 at the First Affiliated Hospital of Nanchang University. The initial dose was 0.3 mg/kg. The blood pressure and heart rate fluctuations during intubation were either <20% (negative cardiovascular response) or ≥20% (positive cardiovascular response). If positive, the dose of the next patient was increased by 0.02 mg/kg, while if negative, it was reduced by 0.02 mg/kg according to the 95:5 biased coin design (BCD). The ED₉₅ and 95% confidence intervals (CIs) were determined using R-Foundation isotonic regression and bootstrapping methods. Results: The ED₉₅ of remimazolam tosylate to inhibit the response during tracheal intubation was 0.297 mg/kg (95% CI: 0.231-0.451 mg/kg) and 0.331 mg/kg (95% CI: 0.272-0.472 mg/kg) in frail and non-frail senile patients, respectively. Conculation and Implications: The CI of the two groups overlap, and no difference was detected in the ED₉₅ of remimazolam tosylate in inhibiting endotracheal intubation-related cardiovascular response in frail and non-frail senile patients. These results suggested that remimazolam tosylate is an optimal anesthesia inducer for all elderly patients. Clinical Trial Registration: https://www.chictr.org.cn, identifier ChiCTR2200055709.

Comparison of Remimazolam Tosilate and Etomidate on Hemodynamics in Cardiac Surgery: A Randomised Controlled Trial

Background

Remimazolam tosilate (RT) is a new ultrashort-acting γ-aminobutyric acid subtype A (GABA_A) agonist, with the characteristics of rapid onset and offset, minimal cardiorespiratory depression. Currently, few studies have compared the effect of RT and etomidate on hemodynamics during anesthesia induction. Here, we aimed to compare the hemodynamic effects of different doses of RT and etomidate for anesthesia induction in patients undergoing cardiac surgeries.

Methods

Patients were recruited from January to September 2022 in this single-center, prospective, randomized, double-blind trial. A total of 117 patients undergoing selective valve replacement surgery were randomly divided into low-dose RT (0.2 mg/kg) group (group LR), high-dose RT (0.3 mg/kg) group (group HR), or etomidate (1.5 mg/kg) group (group E), respectively. The primary outcome was hemodynamic fluctuations (mean arterial pressure fluctuation value [∆MAP]; heart rate fluctuation value [∆HR]) during anesthesia induction. Secondary outcomes included the incidence of adverse drug reactions (injection pain and myoclonus) and adverse cardiovascular events, vital signs at different time points and the cumulative doses of vasoactive drugs.

Results

The hemodynamic fluctuations (∆MAP) in group LR and group E were significantly lower than that in group HR. In addition, the incidence of hypotension and the cumulative norepinephrine doses in group E and group LR were also significantly lower than that in group HR. Furthermore, the incidence of injection pain and myoclonus in group LR and group HR were less frequently recorded compared with group E. There were no significant differences in terms of ∆HR, tachycardia, hypertension, severe bradycardia, vital signs at different time points, lactic acid and blood glucose between both groups.

Conclusion

Compared with etomidate, low-dose RT (0.2mg/kg) can not only provide stable hemodynamic parameters but also cause fewer adverse reactions when used for anesthesia induction in patients with cardiac disease.

Feasibility and Safety of Remazolam versus Propofol When Inserting Laryngeal Masks Without Muscle Relaxants During Hysteroscopy

Purpose

This study aimed to evaluate the efficacy and safety of remazolam compared with propofol in patients who underwent laryngeal mask airway (LMA) insertion without the use of muscle relaxant agents during hysteroscopic surgery.

Patients and Methods

A total of 72 patients undergoing hysteroscopy with LMA insertion were assigned to two groups. The patients in the remazolam group received 0.3 μg/kg sufentanil, 0.3 mg/kg remazolam and 1.2 mg/kg remifentanil, whereas the patients in the propofol group received 0.3 μg/kg sufentanil, 2.0 mg/kg propofol and 1.2 mg/kg remifentanil for insertion of the LMA. The primary endpoint was the summed score of the insertion conditions. The secondary endpoints included hemodynamics, the duration of induction, the duration of insertion, tidal volume, plateau pressure and adverse events.

Results

No difference was identified between the propofol group and remazolam group in the median summed score [18.0 (18.0, 18.0), 18.0 (17.0, 18.0), respectively, P > 0.05]. The induction duration was significantly longer (P < 0.05) in the remazolam group than propofol group. The cost of dopamine (P < 0.05) was significantly lower in the remazolam group compared with the patients in the propofol group, while the plateau pressure (P < 0.05) and the incidence of transient mild laryngospasm (P < 0.05) were significantly higher in the remazolam group. No differences were identified between the two groups in terms of heart rate, tidal volume, injection pain or hiccups (P > 0.05).

Conclusion

Remazolam provided similar insertion conditions and better hemodynamic stability than propofol during LMA insertion without the use of muscle relaxant agents. However, a higher incidence of transient mild laryngospasm was found in the remazolam group, which should be considered.

Efficacy and safety of remimazolam tosylate for sedation during upper gastrointestinal endoscopy: study protocol for a multicenter randomized controlled trial

BACKGROUND

Gastrointestinal endoscopy has been associated with difficult experiences and can leave patients with an unpleasant impression. Propofol and midazolam are the most commonly used intravenous anesthetics for sedation during gastrointestinal endoscopy. However, cardiac and pulmonary adverse events are the primary concerns associated with the use of these sedatives. Remimazolam tosylate is an ultra-short-acting benzodiazepine drug with a mild inhibitory effect on the respiratory and circulatory systems. These properties qualify remimazolam tosylate to be used as a replacement for propofol or midazolam as a sedative during gastrointestinal endoscopy. This study aims to describe the efficacy and safety of remimazolam tosylate as a sedative for upper gastrointestinal endoscopy.

METHODS

A multicenter, randomized, single-blind, parallel-controlled, noninferiority clinical study will be conducted to evaluate the efficacy and safety of remimazolam tosylate as a sedative during upper gastrointestinal endoscopy. Participants (n = 1800) will be randomized to receive remimazolam tosylate at 0.15 mg/kg (experimental group 1), remimazolam tosylate at 0.2 mg/kg (experimental group 2), or propofol at 1.5 mg/kg (control group). Procedure success will be assessed and defined as the completion of upper gastrointestinal endoscopy without the administration of a rescue sedative agent or more than two top-up doses of the trial drug in any 5-min period after initial administration. Sedation quality will be evaluated using the Modified Observer's Assessment of Alertness/Sedation score. Adverse events will be recorded to evaluate safety.

DISCUSSION

This study will determine the optimal dosage of remimazolam tosylate during upper gastrointestinal endoscopy and will describe its efficacy and safety. These findings may contribute to a more comfortable and safer experience for patients compared with that when the conventional sedative propofol is used.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04727034. Registered on February 18, 2021.

Effect of Remimazolam Tosilate on Respiratory Depression in Elderly Patients Undergoing Gastroscopy: A Multicentered, Prospective, and Randomized Study

Background

Remimazolam tosilate (RT) is a new type of γ-aminobutyric acid subtype A (GABA_A) receptor agonist, having the possibility to be an ideal sedative drug for procedural sedation. At present, there are few studies on the effect of RT on respiratory depression in elderly patients. We aimed to evaluate the effect of RT on respiratory depression in elderly patients undergoing gastroscopy.

Methods

This prospective, randomized, single-blinded trial recruited patients from eight centers in China between May 2022 and July 2022. A total of 346 elderly patients undergoing gastroscopy were randomly divided into RT group (0.2 mg/kg) or propofol group (1.5 mg/kg), respectively. The primary outcome was the incidence of respiratory depression. Secondary outcomes include the incidence of sedative-related adverse events, the success rate of sedation, time to fully alert, time to loss of consciousness (LOC), time to ready for discharge, as well as the the patients, endoscopists and anethetists' satisfaction.

Results

The incidence of respiratory depression was significantly reduced in the RT group compared with the propofol group (9.8% vs 17.9%, P=0.042). The time of LOC and fully alert in the RT group were longer than that in the propofol group (P < 0.05). The incidences of hypotention (50.9% vs 32.4%, P=0.001) and hypotension requiring treatment (5.8% vs 1.7%, P=0.031) were significantly higher in the propofol group than that in the RT group. The incidence and severity of injection pain were more frequently recorded in the propofol group than that in the RT group (40.5% vs 12.1%, P<0.05). There were no statistically significant differences between the two groups in terms of sedation success rates, time to ready for discharge, endoscopists and anethetists' satisfaction and other sedative-related adverse events.

Conclusion

RT may be a suitable alternative sedative agent for elderly patients undergoing gastroscopy due to its safety profile.

Remimazolam versus propofol for deep sedation/anaesthesia in upper gastrointestinal endoscopy in elderly patients: A multicenter, randomized controlled trial

BACKGROUND AND OBJECTIVE

Propofol is the most commonly used sedative in gastrointestinal endoscopic procedures, but is associated with cardiorespiratory suppression, particularly in elderly patients. Remimazolam is a new short-acting GABA(A) receptor agonist with minimal impact on cardiorespiratory suppression, and may be a viable alternative in elderly patients undergoing endoscopic procedures.

METHODS

This multicenter, randomized controlled trial was conducted between September 2020 and September 2021. Elderly patients (65-85 years of age) scheduled to undergo upper gastrointestinal endoscopy were randomized in 1:1 ratio to receive remimazolam tosilate (300 mg/h) or propofol (3 g/h) in addition to 50-μg fentanyl, until the Modified Observer's Assessment of Alertness/Sedation Scale (MOAA/S) reached ≤1. MOAA/S was maintained at 0 or 1 throughout the procedure using 2.5 mg remimazolam or 0.5 mg/kg propofol boluses in the two groups, respectively. The primary outcome was the rate of hypotension (defined as systolic blood pressure at ≤90 mmHg or > 30% decline vs. the baseline). Bradycardia was defined as heart rate ≤50 per minute; respiratory depression was defined as respiratory rate <8 per minute and/or SpO₂  < 90%.

RESULTS

A total of 400 patients (161 men and 239 women; 70.4 ± 4.6 years of age) were enrolled (200 patients per group). Average body mass index was 22.2 ± 2.4 kg/m² . The rate of hypotension was 36.5% in the remimazolam group and 69.6% in the propofol group (p < 0.001). The remimazolam group also had a lower rate of bradycardia (1.5% vs. 8.5%, p < 0.001), respiratory depression (4.5% vs. 10.0%, p < 0.05) and pain at the injection site (0% vs. 12.0%, p < 0.001).

CONCLUSION

Remimazolam was associated with a lower rate of hypotension in elderly patients undergoing upper gastrointestinal endoscopy under deep sedation/anaesthesia than propofol.

Remimazolam: An Updated Review of a New Sedative and Anaesthetic

Remimazolam (CNS7056) is a novel benzodiazepine for intravenous sedation; it has an ultra-short duration of action and was recently approved for use in procedural sedation and general anaesthesia. It acts on γ-aminobutyric acid type A receptors and is rapidly converted into an inactive metabolite by tissue esterase enzymes. Remimazolam has been successfully used in endoscopic inspection or surgery and general anaesthesia induction and maintenance with fast and predictable onset and recovery times, high procedure success rates, and minor respiratory and hemodynamic fluctuations and without serious drug-related adverse reactions. If needed, the effects of remimazolam can be reversed by flumazenil, which allows prompt termination of sedation. Although remimazolam has great potential for sedation in patients admitted to intensive care units, future studies are needed to evaluate its efficacy and safety in patients requiring sedation for a long period, and numerous studies are warranted to explore the optimal dose in different application scenarios. The review aimed to provide an introduction to the process of remimazolam synthesis and its current clinical uses and future clinical developments.

Efficacy and Safety of the Remimazolam-Alfentanil Combination for Sedation During Gastroscopy: A Randomized, Double-blind, Single-center Controlled Trial

PURPOSE

Propofol infusion is a popular single drug of choice for sedation in the gastrointestinal endoscopy suite. Drug combinations are more beneficial than single-drug regimens in gastroscopy sedation. However, the cardiopulmonary complications of propofol sedation raise concern. Remimazolam is a novel, ultra-short-acting benzodiazepine sedative, and alfentanil is a weak opioid. During endoscopic procedures, remimazolam is an effective and safe sedative procedure. No synergistic effect has been reported when remimazolam was combined with alfentanil in gastroscopy sedation. Here, we evaluated the effective dose, sedative efficacy, and safety of the remimazolam-alfentanil combination in gastroscopy sedation and compared the results with those of the propofol-alfentanil combination.

METHODS

This study was conducted in two parts. In Part 1, Dixon's up-and-down method (sequential distribution) was adopted for determining the 95% effective dose (ED95) (95% CI) and 95% CI of remimazolam combined with 5 µg/kg alfentanil. In Part 2, after obtaining the predictive remimazolam ED95, 161 patients were randomized into the remimazolam group (remimazolam-alfentanil) and the propofol group (propofol-alfentanil). The effectiveness of the drug combinations was measured according to successful sedation parameters. Changes in vital signs and the appearance of adverse events were used to assess the safety of drug combinations. Evaluation of patient and physician satisfaction was included as quality indicators of treatment.

RESULTS

Baseline demographic and clinical characteristics were comparable between the 2 parts of the study. The ED95 of remimazolam in inhibiting a positive response to gastroscopy placement into the pharyngeal cavity was 0.33 mg/kg (95% CI, 0.289 to 1.023). The procedure success rate was 97.53% in the remimazolam group and 97.50% in the propofol group. The difference in the success rate of the procedure between the remimazolam and propofol groups was 0.03% (95% CI, -2.5 to 2.4). However, the incidence of injection pain, hypotension, respiratory depression, and dizziness was lower in the remimazolam group compared with the propofol group (P < 0.05). Furthermore, patients from the propofol group were more likely to be drowsy, and their work efficiency was reduced the day after leaving the hospital, whereas patients in the remimazolam group were less affected (P < 0.05).

IMPLICATIONS

The ED95 of remimazolam was 0.33 mg/kg when it was combined with alfentanil (5 µg/kg) for gastroscopy sedation. The sedation strategy of remimazolam-alfentanil has noninferior efficacy, fewer adverse effects, and a better postoperative recovery process than propofol-alfentanil for patients undergoing gastroscopy. Chinese Clinical Trials Registry identifier: ChiCTR2100051565.

Profile of Remimazolam in Anesthesiology: A Narrative Review of Clinical Research Progress

Remimazolam is a novel short-acting γ-aminobutyric acid (GABA) receptor agonist with typical characteristics of benzodiazepine sedative drugs, nonorgan-dependent metabolism, long-term infusion without accumulation, and no injection pain. It is quite different from the other current sedative drugs and has broad prospects for application. It has been established that the metabolites of remimazolam are inactive, and the interactions with other drugs are weak with slight cardiopulmonary suppressive effects, showing good effectiveness and safety. During the 2-year period that it has been on the market, remimazolam has been used in multiple clinical scenarios, such as the induction and maintenance of general anesthesia and sedation in outpatient minor procedures or examinations. However, it's use has also prompted widespread concern around the world. Therefore, given its short- and rapid-acting, controllable characteristics remimazolam deserves in-depth study in order for it to be used in fast-track surgery, comfort diagnosis and treatment. Notably, such agents might be of great significance, especially in elderly individuals, patients with critical diseases or patients with liver and kidney insufficiency. The current study reviews recent clinical studies (2015-2022) on remimazolam and summarizes the characteristics of its applications. Specifically, the use of remimazolam in some specific populations are described. This study attempts to provide scientific support for the clinical application of this novel sedative drug in the field of anesthesia.

Sedative effect of remimazolam combined with alfentanil in colonoscopic polypectomy: a prospective, randomized, controlled clinical trial

Background

Remimazolam is a newer benzodiazepine with properties of rapid onset, short duration of action, and fast recovery. Our study was to evaluate the effects of different doses of remimazolam combined with alfentanil in colonoscopic polypectomy.

Methods

One hundred twenty patients were randomly divided into four groups: alfentanil and propofol (AP) group, alfentanil and remimazolam 0.1 mg/kg (AR1 group), 0.15 mg/kg (AR2 group), or 0.2 mg/kg (AR3 group). Patients in the four groups received alfentanil 10 μg/kg, followed by propofol 2 mg/kg and three dosages of remimazolam. Modified Observer's Assessment of Alertness and Sedation (MOAA/S) scale, heart rate (HR), oxygen saturation (SpO₂), respiratory rate (RR), bispectral index (BIS) values and mean arterial pressure (MAP) were collected at intervals of 5 min and analyzed at different time points: before anesthesia (T0), 5 min (T1), 10 min (T2), 15 min after anesthesia (T3) and at the end of surgery (T4). The average MAP was calculated utilizing the average of all MAP values. The primary outcome was the success rate of sedation. Secondary outcomes included time to full alert and adverse events.

Results

The success rate of sedation was 100% among the four groups. The incidence of hypotension was significantly decreased (all P < 0.05) and the average MAP was higher in AR1-AR3 groups than AP group (all P < 0.001). None of the patients developed bradycardia or hypertension during surgery in all study groups. BIS values were higher (all P < 0.001) and the time to full alert was statistically shorter in AR1-AR3 groups (all P < 0.05) compared with the AP group. The MOAA/S score in AR1 was higher than AR2 (P < 0.05) and the AR3 group (P < 0.05) at T1 and BIS values in the AR1 group were significantly higher than AR3 group (P < 0.05) at T4.

Conclusions

Remimazolam combined with alfentanil have a non-inferior sedative effect than propofol during the colonoscopic polypectomy. Moreover, this combination of two short-acting drugs might be a safer alternative.

Trial registration

The clinical trial was registered on (16/05/2021, ChiCTR2100046492).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01805-3.

Total intravenous anesthesia induced and maintained by a combination of remimazolam and remifentanil without a neuromuscular blocking agent: a prospective, observational pilot study

Background

A novel short-acting benzodiazepine, Remimazolam, has recently been approved for general anesthesia and sedation. Hence, we investigated the feasibility and safety of remimazolam during the induction and maintenance of general anesthesia without using a neuromuscular blocking agent (NMBA) in patients undergoing hysteroscopic surgery.

Methods

This prospective observational study included 38 patients undergoing hysteroscopic surgery. Remimazolam and remifentanil were the main anesthetic agents without an NMBA, and a supraglottic airway was inserted to protect the airway. The induction time, amount of each anesthetic agent used during anesthesia, intraoperative bispectral index (BIS) hemodynamic parameters, and recovery profiles were measured.

Results

General anesthesia was successfully administered to 37 patients using remimazolam and remifentanil without NMBA. The induction doses of remimazolam and remifentanil were 0.4 mg/kg (interquartile range [IQR] 0.34–0.47 mg/kg) and 1.07 μg/kg (IQR, 0.90–1.29 μg/kg), respectively. Additionally, the maintenance doses of remimazolam and remifentanil were 1.14 mg/kg/h (IQR, 0.88–1.55 mg/kg/h) and 0.06 μg/kg/min (IQR, 0.04–0.08 μg/kg/min), respectively. Intraoperative BIS values had risen temporarily > 60 in eight patients (21.6%) despite administration of 2 mg/kg/h of remimazolam; thus, they were treated with supplementary midazolam. The median recovery time was 7 min (IQR, 5–8 min) after 40 min (IQR, 40.0–57.5 min) of total mean anesthesia time. There was no correlation between the infusion dose of remimazolam and recovery profiles, such as recovery time, final BIS of anesthesia, modified observer assessment of alertness/sedation (OAA/S) scale or post-anesthesia recovery (PAR) score when arriving at the PACU, and length of stay in the PACU (all P > 0.05).

Conclusion

Remimazolam can be combined with remifentanil without an NMBA in female patients who undergo hysteroscopic surgery, during which a supraglottic airway is a feasible method to protect the airway.

Trial registration

The study protocol was registered at ClinicalTrials.gov (NCT05025410) on 27/08/2021.

The Clinical Application of Remimazolam Benzenesulfonate Combined with Esketamine Intravenous Anesthesia in Endoscopic Retrograde Cholangiopancreatography

In this project, algorithm-based image processing methods in 3D endoscopic image processing endoscopic retrograde cholangiopancreatography (ERCP) were analyzed. To enhance local information of images, an adaptive histogram equalization method with limited contrast is introduced. The influences of the algorithm on 3D endoscopic image peak signal-to-noise ratio (PSNR), image discrete information entropy (DE), and average mean brightness error (AMBE) of images before and after the optimization before were compared. A total of 92 patients receiving ERCP at Yuhuangding Hospital between December 2019 and December 2021 were selected and divided into the control group (fentanyl+propofol) and the observation group (remimazolam benzenesulfonate+esketamine). Mean arterial pressure heart rate (HR), oxygen saturation (SpO2), and respiratory rate (RR) of the patients at each time point including the entry into the operation room (T0), 2 minutes after the beginning of medication (T1), after endoscopy (T2), endoscopy withdrawal (T3), and postoperative awakening (T4) were recorded. The comparison of MAP between T1, T2, T3, and T4 and T0 among patients in the observation group and the control group showed statistical differences (P < 0.05). Besides, HR and RR at T4 in the observation group were obviously higher than those in the control group (P < 0.05). The comparison of SpO2 at T3 and T4 and that at T0 both showed statistical differences (P < 0.05). Awakening time and VAS scores in the observation group were obviously lower than those in the control group (P < 0.05). The incidence of bradycardia, nausea, vomiting, and chill in the observation group was all lower than that in the control group (P < 0.05). The results indicated that an effective endoscopic image processing method was established based on an image enhancement algorithm, and the combination of remimazolam benzenesulfonate and esketamine showed high safety and efficacy in ERCP.

The Median Effective Dose and Bispectral Index of Remimazolam Tosilate for Anesthesia Induction in Elderly Patients: An Up-and-Down Sequential Allocation Trial

Purpose

Remimazolam is a new type of ultrashort benzodiazepine drug with an unclear optimal dose for general anesthesia induction in elderly patients aged >60 years. Therefore, this study aimed to determine the effective dose of remimazolam tosilate induction and explore its correlation with the bispectral index (BIS).

Patients and Methods

A total of 42 elderly patients were divided into two age groups: 60–69 (group A) and 70–85 (group B) years. An initial dose of 0.1mg/kg(Group A) and 0.05 mg/kg(Group B) remimazolam tosilate was administered, and the Modified Observer’s Assessment of Alertness/Sedation scale was used to assess adequate responses. The dose was calculated using the up-and-down allocation technique based on the previous response. The sequential formula and probit regression model were used to calculate ED50 and BIS50. ED95 was determined using the probit regression model.

Results

The ED50 of remimazolam tosilate for anesthesia induction were 0.088 mg/kg (95% confidence interval [CI] 0.071–0.108) and 0.061 mg/kg (95% CI 0.053–0.069) in groups A and B, respectively. ED95 was 0.118 mg/kg (95% CI 0.103–0.649) and 0.090 mg/kg (95% CI 0.075–0.199) in groups A and B, respectively. The remimazolam tosilate administration could decrease BIS. BIS50 was 86.0 (95% CI 83.7–88.6) and 85.4 (95% CI 84.1–86.8) in groups A and B, respectively.

Conclusion

During the induction process, patients’ consciousness should be observed. The dose of remimazolam tosilate could be chosen after careful consideration of individual variations.