Remimazolam: A Novel Option for Procedural Sedation in High Risk Patients

Remimazolam

Remimazolam is a new reversible γ-aminobutyric acid type A agonist benzodiazepine that displays a fast onset of action, short recovery time with a safe cardiopulmonary profile and favorable pharmacokinetics in comparison with other intravenous sedatives.

Hemodynamic Stability of Midazolam versus Remimazolam During Outpatient Genitourinary Interventional Radiology Procedures in a Patient With Aortic Stenosis: A Case Report

Patients with aortic stenosis (AS) and other significant cardiopulmonary comorbidities are vulnerable to hemodynamic instability during anesthesia. This case report compares the use of remimazolam and midazolam in a 71-year-old man with symptomatic AS, chronic kidney disease, and ischemic cardiomyopathy. The patient underwent multiple short ambulatory interventional radiology procedures. While moderate sedation with midazolam resulted in significant hypotension, use of remimazolam in subsequent procedures demonstrated a stable hemodynamic profile despite increased disease burden. This report highlights the potential advantages of remimazolam compared to midazolam in high-risk patients undergoing interventional radiology procedures.

Expiratory Central Airway Collapse and Pneumatic Stenting With Continuous Positive Pressure Titration: A Technique Description

OBJECTIVE

To provide a standardized step-by-step guide for continuous positive airway pressure (CPAP) titration during dynamic flexible bronchoscopy (DB).

PATIENTS AND METHODS

This descriptive study included patients referred to Mayo Clinic for concern regarding expiratory central airway collapse (ECAC) who underwent DB with CPAP titration from April 5, 2023, to February 9, 2024. Demographic characteristics, comorbidities, pulmonary function test results, and procedural details such as anesthesia protocols, CPAP settings, outcomes of pneumatic stenting, complications, and severity of ECAC were recorded. The procedure is performed with the patient under light sedation. After assessing dynamic breathing maneuvers for airway collapsibility, a CPAP mask is attached with initial pressure set at 6 cm H2O and titrated in increments of 2 cm H2O until successful pneumatic stenting of the airway.

RESULTS

The study group included 33 patients. The mean ± SD age was 67.45±8.73 years, 21 (63.6%) were female, and 26 (78.8%) presented with shortness of breath. The median ECAC severity score was 11 (IQR, 7 to 13). Of the 32 patients who underwent pulmonary function tests, 20 (62.5%) had normal results and 12 (37.5%) had a serrated flow-volume loop. The median CPAP setting to maintain airway patency was 12 cm H2O (IQR,10 to 14 cm H2O). We reported no intraprocedural or postprocedural complications.

CONCLUSION

This study provides a detailed guide to performing CPAP titration during DB. We believe that this description of technique will support a systematic approach for further research to assess the impact of pneumatic stenting in ECAC.

Remimazolam for anesthesia and sedation in pediatric patients: a scoping review

Anesthetic management of pediatric patients poses several challenges and the optimal anesthetic agent for use in this population is still a matter of debate. We systematically searched PubMed/MEDLINE and Google Scholar from their inception for studies that investigated the role and potential applications of remimazolam, a novel ultra-short-acting benzodiazepine, in pediatric patients. Furthermore, in March 2024, an update of the literature search along with an additional post-hoc search on the EMBASE database were performed. A total of fourteen pertinent studies which spanned the 2021-2023 period explored remimazolam as either the primary or adjuvant hypnotic agent for inducing and/or maintaining general anesthesia or sedation. Preliminary evidence derived from these studies highlighted that remimazolam is a safe and effective option for both sedation and general anesthesia in pediatric patients, particularly those with concurrent mitochondrial disorders, myopathic diseases, or at risk for malignant hyperthermia. Moreover, the current evidence suggested that remimazolam may contribute to reducing preoperative anxiety and postoperative delirium in children. Its favorable pharmacodynamic and pharmacokinetic profile demonstrated potential safety, effectiveness, and ease-of-use in various perioperative pediatric contexts, making it suitable for integration into specific protocols, such as intraoperative monitoring of evoked potentials and management of difficult intubation. Notwithstanding these promising findings, further research is essential to determine optimal dosages, establish conclusive evidence of its superiority over other benzodiazepines, and elucidate the impact of genetic factors on drug metabolism.

Remimazolam and Its Place in the Current Landscape of Procedural Sedation and General Anesthesia

Remimazolam was derived from its parent compound by adding an ester linkage into its structure so that the drug becomes a substrate for ester metabolism. As a result, it undergoes organ-independent ester hydrolysis, although the clinical benefits in terms of shorter recovery are not uniformly observed in clinical practice. Remimazolam is mainly tested in procedural sedation. In comparison to propofol, the current gold standard for procedural sedation, its proposed attractiveness is shorter wake-up times and a clear-headed recovery. Its clear advantages over propofol are better hemodynamic stability, lack of pain on injection and availability of a reversal agent in the form of flumazenil. Data on patient and proceduralist satisfaction are lacking. Remimazolam is also used for induction and maintenance of general anesthesia in Japan (where it is approved for this purpose). In this scenario, it is not clear if it can achieve the same degree of lack of recall as propofol. The use of remimazolam in obstetrics, pediatrics and high-risk populations is an emerging area.

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.

The 90% effective dose (ED90) of remimazolam for inhibiting responses to the insertion of a duodenoscope during ERCP

BACKGROUND

Compared to midazolam, remimazolam has a faster onset and offset of hypnotic effect, as well as cardiorespiratory stability, this study aims to determine the 90% effective dose (ED90) of remimazolam to inhibit responses to insertion of a duodenoscope during endoscopic retrograde cholangiopancreatography (ERCP).

METHODS

A dose-response study was carried out undergoing ERCP who received remimazolam-alfentanil anesthesia using 10 µg/kg of alfentanil between September 2021 and November 2021. The initial dose of remimazolam was 0.2 mg/kg. The dose was then decided based on the responses of earlier patients by exploiting the sequential ascend and descend according to a 9: 1 biased coin design. Upon failure, the dose of remimazolam was increased by 0.025 mg/kg in the next patient. When the insertion was successful, the succeeding patient was randomized to an identical dose or a dose that was lower by 0.025 mg/kg.The ED90 of remimazolam for inhibiting responses to the insertion of a duodenoscope during ERCP was calculated. Adverse events and complications of remimazolam were recorded.

RESULTS

A total of 55 elderly patients (age > 65) were included in the study. 45 successfully anesthetized patients, and 10 unsuccessfully. The ED90 of remimazolam was 0.300 mg/kg (95% CI = 0.287-0.320). ED95 was 0.315 (95% CI = 0.312-0.323) and ED99 was 0.323 (95% CI = 0.323-0.325). Among the patients, 9 patients developed hypotension, 2 patients developed bradycardia and 1 patient developed tachycardia, and hypoxia occurred in 2 patients.

CONCLUSIONS

A loading dose of 0.300 mg / kg of remimazolam for elderly patients undergoing ERCP can safely, effectively, and quickly induce patients to fall asleep and inhibit responses to the insertion of a duodenoscope.

TRIAL REGISTRATION

The study protocol was registered at the website ClinicalTrials.gov on 22/09/2021(NCT05053763).

Benefits of remimazolam as an anesthetic sedative for older patients: A review

Owing to the decreased levels of receptors in the peripheral and central nervous systems, the functions of various organ systems decline in older patients. When administering anesthesia to older patients, it is necessary to consider the effects of medication on the homeostatic balance. Remimazolam, a new benzodiazepine, was recently developed as an anesthetic drug that has shown promise in clinical anesthesia application owing to its molecular structure, targets, pharmacodynamics, and pharmacokinetic characteristics. Remimazolam exhibits a rapid onset and metabolism, with minor effects on liver and kidney functions. Moreover, the drug has a specific antagonist, flumazenil. It is safer to use in older patients than other anesthetic sedatives and has been widely used since its introduction. Comparisons of the pharmacokinetics, metabolic pathways, effects on target organs, and hemodynamics of different drugs with those of commonly used anesthetic sedative drugs are useful to inform clinical practice. This article elaborates on the benefits of remimazolam compared with those of other anesthetic sedatives for sedation in older patients to demonstrate how it offers a new option for anesthetics in older patients. In cases involving older patients with increased clinical complexities or very old patients requiring anesthesia, remimazolam can be selected as the preferred anesthetic sedative, as outlined in this review.

The Efficacy and Safety of Remimazolam Tosilate Versus Dexmedetomidine in Outpatients Undergoing Flexible Bronchoscopy: A Prospective, Randomized, Blind, Non-Inferiority Trial

Purpose: This study aimed to compare the efficacy and safety of remimazolam tosilate-remifentanil (RT-RF) vs dexmedetomidine-remifentanil (Dex-RF) for outpatients undergoing fiberoptic bronchoscopy (FB).

Patients and methods: We conducted a double-blind, randomized, prospective study involving a total of 146 outpatients undergoing FB divided into two groups. The RT-RF (RR) group (n = 73) received an initial dose of 12 mg/kg/h of RT for 10 min followed by a maintenance dose of 1–2 mg/kg/h, while the Dex-RF (DR) group (n = 73) received an initial dose of 0.5 μg/kg of Dex for 10 min followed by a maintenance dose of 0.2–0.7 μg/kg/h. All outpatients also received 0.05–0.2 μg/kg/min RF to maintain the Modified Observer’s Assessment of Alertness and Sedation (MOAA/S) scale <3. The primary outcome was rate of successful FB completed. Secondary outcomes were time metrics, hemodynamics, intubating conditions, oxygen saturation, coughing severity, number of remedies, total dose of fentanyl, RF, RT, and Dex, incidence of dreaming, patient and bronchoscopist satisfaction, willingness to repeat bronchoscopy, and adverse events.

Results: The FB successful completion rate was 94.52% (95% CI: 89.20–99.90) in the RR group and 91.78% (95% CI: 85.30–98.20) in the DR group. Compared with patients in the DR group, the onset time, time to fully alert, and hospital discharge were all significantly shorter in the RR group (p < 0.01), and hemodynamics were more stable in the RR group. Intubating conditions, clinically acceptable intubating conditions, lowest oxygen saturation, coughing severity, consumption of fentanyl and RF, number of remedies, and patient and bronchoscopist satisfaction were similar between the groups (p > 0.05), as were demographic characteristics, incidence of dreaming, willingness to repeat bronchoscopy, and adverse events (p > 0.05).

Conclusion: RT-RF has non-inferior efficacy, better time metrics and hemodynamic stability for outpatients undergoing FB than Dex-RF.

Systematic Review Registration: [http://www.chictr.org.cn/showproj.aspx?proj=66673], identifier [ChiCTR2000041524].