Anaesthetic management using remimazolam in a patient with severe aortic stenosis: a case report

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.

A Retrospective Comparative Study of the Frequency of Hypotension in Pediatric Cardiac Catheterization under General Anesthesia: Remimazolam versus Sevoflurane

OBJECTIVE

To compare the incidence of hypotension between remimazolam and sevoflurane under general anesthesia for cardiac catheterization in patients with congenital heart disease.

DESIGN

Retrospective observational study.

SETTING

A single university hospital with 300 pediatric cardiac catheterizations by general anesthesia performed annually.

PARTICIPANTS

Patients younger than 15 years who underwent cardiac catheterization under general anesthesia between March 1, 2021, and December 31, 2022. Exclusion criteria were general anesthesia maintained with other than remimazolam or sevoflurane, receipt of remifentanil, American Society of Anesthesiologists score 4 or 5, emergency procedures, and no direct arterial pressure measurement.

INTERVENTIONS

General anesthesia was maintained with remimazolam or sevoflurane.

MEASUREMENTS AND MAIN RESULTS

A total of 309 patients were analyzed, including 28 in the remimazolam group and 281 in the sevoflurane group. Propensity score matching adjusted for confounding factors resulted in 28 patients in each arm, with no apparent differences in background factors. Hypotension was defined as a time-averaged area > 1, in which systolic arterial pressure fell below 80% of the baseline from the start of anesthesia to the end of procedure. The significance level was set at P < .05. The incidence of hypotension was 39.3% in the remimazolam arm and 46.4% in the sevoflurane arm, with no significant difference (P = .79), although the ratio of the median systolic arterial pressure to the baseline value was significantly higher in the remimazolam arm (91.4 ± 15.2% vs 83.2 ± 11.4% in the sevoflurane arm; P = .03).

CONCLUSIONS

Remimazolam was not associated with a lower incidence of hypotension compared to sevoflurane during pediatric cardiac catheterization for congenital heart disease while maintaining significantly higher blood pressure overall.

Remimazolam for anesthesia and sedation in cardiac surgery and for cardiac patients undergoing non-cardiac surgery: a systematic-narrative hybrid review

INTRODUCTION

Remimazolam, an ultra-short-acting benzodiazepine recognized and approved as an anesthetic and sedative in multiple countries, offers a distinctive pharmacokinetic profile, boasting advantages such as rapid onset, short action duration, and rapid recovery. These attributes may contribute to enhanced hemodynamic stability and a diminished risk of respiratory depression compared to other sedatives.

EVIDENCE ACQUISITION

We conducted the first comprehensive systematically structured narrative review to evaluate the role and potential application of remimazolam in cardiac surgery. Twenty-one studies published from 2021 to 2023 delved into remimazolam's application in open cardiac surgery, cardiac catheterization or electrophysiology laboratories, and high-risk cardiovascular patients undergoing non-cardiac surgery.

EVIDENCE SYNTHESIS

Overall, remimazolam usage was apparently linked to potentially superior hemodynamic stability compared to other hypnotic drugs. However, findings regarding the reduction in postoperative delirium incidence with remimazolam and the doses of remimazolam for anesthesia induction and maintenance were inconsistent across the studies.

CONCLUSIONS

Though remimazolam has demonstrated potential safety, efficacy, and ease-of-use for both anesthesia induction and maintenance in cardiac surgery patients and high-risk cardiovascular patients undergoing non-cardiac surgery, further research is imperative to delve into specific patient subgroups (e.g., the elderly or emergent procedures) so as to ascertain optimal dose ranges to suit diverse clinical scenarios.

Efficacy of remimazolam tosilate versus propofol for total intravenous anaesthesia in urological surgery: A randomised clinical trial

BACKGROUND

Remimazolam is a novel ultra-short-acting benzodiazepine sedative that acts on the gamma-aminobutyric acid type A receptor (GABAAR).

OBJECTIVE

To compare the efficacies of remimazolam (RMZ), and propofol (PROP) combined with remifentanil and cisatracurium for total intravenous anaesthesia (TIVA) in patients undergoing urological surgery.

DESIGN

A prospective, single-blind, randomised, noninferiority clinical trial.

SETTING

Single centre from 1 January 2022 to 30 March 2022.

PATIENTS

A total of 146 adult patients undergoing elective urological surgery.

INTERVENTION

Patients were randomly allocated in a 1 : 1 ratio to the PROP or RMZ groups. In the PROP group, anaesthesia was induced with propofol at 100 mg min -1 to reach a bispectral index score (BIS) of 40 to 60. After loss of consciousness (LOC), intravenous fentanyl 3 μg kg -1 was administered, followed by cisatracurium 0.3 mg kg -1 . Patients were intubated 3 min after cisatracurium administration. Anaesthesia was maintained with the combination of propofol (plasma concentration: 2.5 to 4 μg ml -1 ) and remifentanil (plasma concentration: 2.5 to 4 ng ml -1 ). In the RMZ group, anaesthesia was induced with remimazolam tosilate starting at 10 mg kg -1  h -1 to reach a BIS of 40 to 60 and maintained between 0.2 and 2 mg kg -1  h -1 . After LOC, fentanyl and cisatracurium were administered and intubation was performed as in the PROP group. Anaesthesia was maintained with a combination of remimazolam (0.2 to 2 mg kg -1  h -1 ) and remifentanil (plasma concentration: 2.5 to 4 ng ml -1 ).

MAIN OUTCOME MEASURES

The primary outcome was the TIVA success rate. The predefined noninferiority margin considered an absolute difference of 6% in the primary outcome between the groups. The secondary outcomes were vital signs, anaesthesia and surgery characteristics, and adverse events.

RESULTS

All patients completed the trial. The success rates of TIVA with remimazolam and propofol were 100 and 98.6%, respectively. The incidence of hypotension during anaesthesia was lower in the RMZ group (26%) than in the PROP group (46.6%) ( P  = 0.016). The median [IQR] total consumption of ephedrine during anaesthesia was higher in the PROP group 10 [0 to 12.5] mg than in the RMZ group 0 [0 to 10] mg ( P  = 0.0002). The incidence of injection pain was significantly higher in the PROP group (76.7%) than in the RMZ group (0; P  < 0.001). No significant differences in the controllability of the anaesthesia depth, anaesthesia and surgery characteristics, or vital signs were observed between the groups.

CONCLUSION

Remimazolam demonstrated noninferior efficacy to propofol combined with remifentanil and cisatracurium for TIVA in patients undergoing urological surgery.

TRIAL REGISTRATION

Chictr.org.cn, identifier: ChiCTR2100050923.

CLINICAL REGISTRATION

The study was registered in the Chinese Clinical Trial Registry (ChiCTR2100050923, Principal investigator: Xuehai Guan, Date of registration: 8 November 2021, https://www.chictr.org.cn/showproj.html?proj=133466 ).

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.

Remimazolam-Based Anesthesia in Patients with Heart Failure Due to Mitral Regurgitation and Low Left Ventricular Function: A Case Series

Background and Objectives: Remimazolam is a new ultrashort-acting benzodiazepine anesthetic. Remimazolam appears to be useful in patients with severe valvular disease because of its minimal cardiovascular impact. In this retrospective case series study, we assessed the efficacy and safety of remimazolam for maintaining hemodynamic stability during anesthetic induction and maintenance. Cases: MitraClip was performed on 18 cases with severe mitral regurgitation with low left ventricular function who presented with heart failure, and remimazolam was administered for general anesthesia with induction (12 mg/kg/h) and maintenance (1 mg/kg/h). The impact of remimazolam on the hemodynamics at anesthetic induction and during anesthetic maintenance was investigated retrospectively using electronic medical records. Blood pressure decreased significantly during anesthetic induction with remimazolam (78.5 [72, 81.25] and 66.1 [62.2, 74.2], median [IQR], p = 0.0001), but only mildly, by about 10 mmHg. There was no significant change in the cardiac index (2.0 [1.8, 2.4] vs. 1.9 [1.8, 2.3], p = 0.57642) or pulse rate (73.5 ± 8.85 vs. 74.7 ± 11.7, mean ± SD, p = 0.0876) during anesthetic induction with remimazolam. All patients underwent MitraClip without major hemodynamic concerns, with no or small increases in inotropes. Conclusions: Remimazolam may be used safely in patients with severe mitral regurgitation and low left ventricular function presenting with heart failure.

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 .

Anesthetic management with remimazolam in very elderly patients undergoing hybrid surgery of transcatheter aortic valve implantation plus off-pump coronary artery bypass grafting: report of two cases

BACKGROUND

Remimazolam is a short-acting benzodiazepine with small circulatory depression. We used remimazolam for general anesthesia management in two very elderly patients undergoing hybrid surgery of transcatheter aortic valve implantation (TAVI) plus off-pump coronary artery bypass grafting (OPCABG).

CASE PRESENTATION

A 96-year-old man (case 1) and a 92-year-old woman (case 2) had complex coronary artery disease (CAD) and severe aortic stenosis (AS) and were scheduled for TAVI plus OPCAB. Anesthesia in both patients was induced with 6 mg/kg/h remimazolam and fentanyl and maintained with 0.3 mg/kg/h and 0.5 mg/kg/h remimazolam and fentanyl, respectively. Although catecholamines were required, we successfully maintained circulation during the induction of anesthesia and the procedures of OPCAB and TAVI. Both patients were discharged without complications.

CONCLUSION

Remimazolam can be a useful option for safe general anesthesia in very elderly patients when performing hybrid surgery.

Anesthesia using remimazolam during coronary artery bypass surgery in a patient with decreased left ventricular function

Key Clinical Message

Remimazolam is a new benzodiazepine sedative and has the characteristic of causing minimal effects on circulation. This case indicates that it can be considered as an option for anesthesia management of patients with decreased cardiac function.

Abstract

Some patients who undergo cardiac surgery have reduced cardiac function, which can often make anesthesia management difficult owing to severe hypotension at the time of anesthesia induction. Therefore, it is important to select drugs that cause minimal circulatory depression. On the other hand, in 2020, the use of remimazolam, a short-acting benzodiazepine sedative, was approved in Japan, and reports of its use in various patients have been increasing. This drug has the characteristic of causing minimal effects on circulation. We here report the safe use of remimazolam in the anesthesia management of a patient with decreased cardiac function who was diagnosed as having angina pectoris. The patient was a 73-year-old man scheduled for coronary artery bypass graft (CABG) surgery. Remimazolam was used for sedation purposes during anesthesia induction. During surgery, there were no significant hemodynamic changes and the patient remained in stable cardiovascular condition. Our present case indicates that remimazolam can be considered as an option for anesthesia management in CABG for patients with decreased cardiac function.

Can remimazolam be safely used in cardiac tamponade?: A case report

RATIONALE

Remimazolam, a benzodiazepine drug, has recently been developed and is currently used for the induction and maintenance of anesthesia. Remimazolam provides hemodynamic stability during anesthesia induction. However, in patients with cardiac tamponade, it is unclear how hemodynamic stability is maintained during the induction and maintenance of general anesthesia with remimazolam.

PATIENT CONCERNS

An 88-year-old male patient had developed hemopericardium due to penetration of a pigtail catheter into the left ventricle during pericardiocentesis, which was performed to treat massive pericardial effusion.

DIAGNOSES

The patient was diagnosed with acute cardiac tamponade and a hemothorax. Hemopericardium and hemothorax were confirmed on chest radiography and computed tomography performed immediately after pericardiocentesis.

INTERVENTIONS

Decompressive pericardiostomy was performed through a left anterolateral thoracotomy with 1-lung ventilation under general anesthesia. Remimazolam was administered for total intravenous anesthesia.

OUTCOMES

Severe hypotension and bradycardia occurred during the induction of anesthesia with remimazolam (6 mg/kg/hours).

LESSONS

Remimazolam may induce severe hemodynamic instability during induction of general anesthesia in patient with cardiac tamponade.

Evaluation of total intravenous anesthesia with remimazolam in general anesthesia for pulmonary endarterectomy of chronic thromboembolic pulmonary hypertension: a case report

BACKGROUND

Pulmonary endarterectomy (PEA) is a treatment modality for chronic thromboembolic pulmonary hypertension (CTEPH). PEA requires anesthesia management to prevent an increase in pulmonary vascular resistance (PVR) and circulatory failure. Therefore, it is necessary to select an anesthetic agent that can achieve these goals as much as possible. On the other hand, remimazolam, a short-acting sedative, was launched in Japan in 2020, and its use in various cases has been increasingly reported. This report demonstrates that remimazolam can be used safely in the anesthetic management of PEA.

CASE PRESENTATION

A 57-year-old man was scheduled to undergo PEA for CTEPH. Remimazolam was used for sedation from induction of anesthesia. Hemodynamics were stable during surgery without circulatory failure. Anesthesia was managed intraoperatively without any particular increase in PVR.

DISCUSSION

Anesthesia was successfully managed without any complications. This case suggests that remimazolam is one of the options for anesthetic management in PEA.

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.

Efficacy and safety of remimazolam for non-obese patients during anesthetic induction in cardiac surgery: study protocol for a multicenter randomized trial

BACKGROUND

Valvular heart disease remains common in both developed and developing countries, and it requires timely surgical treatment when necessary. However, the stability of hemodynamics during anesthesia induction in patients undergoing valve replacement surgery is difficult to maintain due to their impaired cardiac function. Remimazolam, a novel and ultrashort-acting intravenous sedative-hypnotic, may be beneficial to stable hemodynamics, but the evidence is limited. Therefore, this study aims to evaluate the effect of remimazolam induction on hemodynamics compared with midazolam and etomidate in patients undergoing valve replacement surgery.

METHODS

This is a prospective, multicenter randomized controlled trial (RCT). Three hundred and sixty-three non-obese adult patients aged 45 to 80 years old undergoing valve surgery with cardiopulmonary bypass will be randomly allocated to receive remimazolam tosilate, midazolam, or etomidate during anesthetic induction. The primary outcome is the incidence of hypotension within 20 min after the administration of investigated drugs. The hypotension is defined as systolic blood pressure (SBP) < 90 mmHg or a 30% reduction in SBP from baseline or the application of vasoactive drugs. Secondary outcomes include incidence of successful sedation, time to successful sedation, incidence of delirium and postoperative low cardiac output syndrome within 7 days after surgery, hospital mortality, mechanical ventilation time, ICU length of stay, and hospital length of stay.

DISCUSSION

To our knowledge, this is the first prospective RCT to investigate the efficacy and safety of remimazolam induction in adult cardiac surgery compared with midazolam and etomidate. This study will provide important information on the application of remimazolam in cardiac surgery in the future.

TRIAL REGISTRATION

Chinese Clinical Trial Registry chictr.org.cn ChiCTR2100050122. Registered on August 16, 2021.

Assessing the Safety of Total Intravenous Anesthesia with Remimazolam in General Anesthesia for Transcatheter Aortic Valve Implantation of Severe Aortic Valve Stenosis: A Case Series

Background and Objectives: In patients with severe aortic stenosis (sAS), it is crucial to maintain hemodynamic stability during the induction and maintenance of general anesthesia for transcatheter aortic valve implantation (TAVI). In this study, we assessed the efficacy and safety of remimazolam in maintaining hemodynamic stability during anesthetic induction and maintenance. Cases: TAVI was performed on seven patients with sAS, and remimazolam was administered for total intravenous anesthesia (TIVA) of general anesthesia with induction (3.0 mg/kg/h) and maintenance (1.0 mg/kg/h). All patients underwent TAVI without major hemodynamic concerns and later recovered. Conclusions: Remimazolam can be safely used for induction and maintenance of general anesthesia in patients with sAS when performing TAVI.

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.

Anesthetic Management Using Remimazolam for Transcatheter Edge-to-Edge Repair of the Mitral Valve in Patients With Reduced Ejection Fraction: A Case Report of Two Cases

Remimazolam is an ultrashort-acting benzodiazepine that causes minimal hemodynamic changes. We present two patients, with reduced ejection fraction, who underwent remimazolam anesthesia for transcatheter edge-to-edge repair of the mitral valve with the MitraClip system. In case 1, the patient’s vitals were stable throughout the surgery. However, in case 2, which had a lower cardiac output, the patient’s blood pressure decreased remarkably after anesthesia induction. Though remimazolam does not alter the cardiac output, it reportedly has vasodilatory effects. Since remimazolam can reduce blood pressure in patients where the reduction in cardiac output is compensated for by high peripheral vascular resistance, caution should be exercised.

Remimazolam besylate versus propofol for long-term sedation during invasive mechanical ventilation: a pilot study

OBJECTIVE

The aim of this study was to evaluate the efficacy and safety of remimazolam besylate compared with propofol in maintaining mild-to-moderate sedation in patients receiving long-term mechanical ventilation.

METHODS

In this single-centered randomized pilot study, adult patients mechanically ventilated longer than 24 h were randomized to receive remimazolam besylate or propofol. The target sedation range was - 3 to 0 on the Richmond Agitation and Sedation Scale (RASS). The primary outcome was the percentage of time in the target sedation range without rescue sedation. The secondary outcomes were ventilator-free days at day 7, the length of ICU stay and 28-day mortality.

RESULTS

Thirty patients were assigned to each group. No difference was identified between the remimazolam group and propofol group in median age [60.0 (IQR, 51.5-66.3) years vs. 64.0 (IQR, 55.0-69.3) years, respectively, p = 0.437] or the median duration of study drug infusion [55.0 (IQR, 28.3-102.0) hours vs. 41.0 (IQR, 24.8-74.3) hours, respectively, p = 0.255]. The median percentage of time in the target RASS range without rescue sedation was similar in remimazolam and propofol groups [73.2% (IQR, 41.5-97.3%) vs. 82.8% (IQR, 65.6-100%), p = 0.269]. No differences were identified between the two groups in terms of ventilator-free days at day 7, length of ICU stay, 28-day mortality or adverse events.

CONCLUSIONS

This pilot study suggested that remimazolam besylate was effective and safe for long-term sedation in mechanically ventilated patients compared with propofol.

Anesthetic management using remimazolam in a patient with atrial flutter: a case report

Remimazolam is a new intravenously administered ultra-short-acting benzodiazepine used in anesthesia or sedation. Remimazolam offers several advantages over other short-acting sedatives, including an organ-independent metabolism and rapid and predictable onset and recovery. Furthermore, remimazolam shows less cardiovascular-inhibitory effects than other anesthetics. Atrial flutter is a form of cardiac arrhythmia that is associated with serious health-related outcomes and a substantial economic burden. Acute onset of atrial flutter can cause cardiac dysfunction, hypotension, and myocardial ischemia. Moreover, patients with atrial flutter are likely to have an increased risk of both atrial fibrillation and stroke. In this case report, a patient with a 1-year history of atrial flutter underwent general anesthesia for robot-assisted laparoscopic prostatectomy. Using continuous remimazolam infusion, anesthesia and surgery were successfully completed without sudden changes in the patient's blood pressure, heart rate, or electrocardiogram. This case report describes the first reported use of remimazolam to induce general anesthesia in a patient with atrial flutter. The findings suggest that remimazolam can reduce the hemodynamic risk during anesthesia in patients with arrhythmias such as atrial flutter, and is a suitable option for anesthesia in patients with arrhythmias.

Remimazolam - current knowledge on a new benzodiazepine intravenous anesthetic agent

Intravenous anesthetic agents such as midazolam, propofol, and ketamine are routinely used to provide anesthesia and sedation. They have been shown to effectively induce and maintain amnesia, sedation, and hypnosis in various patient groups and clinical settings. However, all anesthetic agents have the potential to cause unwanted side effects such as hemodynamic instability, respiratory depression, or slow recovery due to prolonged post-procedural sedation. Remimazolam, a recently approved benzodiazepine for general anesthesia and procedural sedation in Korea, has been successfully used for these purposes. To date, inconclusive knowledge has been obtained regarding the use of remimazolam in different patient populations and under various surgical conditions. With respect to the specific pharmacokinetic and pharmacodynamic characteristics of remimazolam, the use of remimazolam is expected to increase providing safe general anesthesia and sedation. This review aims to provide an overview of the basic and clinical pharmacology of remimazolam and to compare it with midazolam and propofol.

Remimazolam for induction of anesthesia in elderly patients with severe aortic stenosis: a prospective, observational pilot study

Background

Remimazolam, a novel benzodiazepine, has been reported to cause less hypotension than propofol during induction of anesthesia. Therefore, remimazolam might be a valuable option in elderly patients with severe aortic stenosis who are considered to be the most vulnerable to hemodynamic instability. We aimed to evaluate the feasibility and hemodynamic effects of remimazolam as an induction agent in elderly patients with severe aortic stenosis.

Methods

This prospective, open-label, single-arm, observational pilot study was conducted in a university hospital between November 2020 and April 2021. We included 20 patients aged 65 years or older scheduled for transcatheter or surgical aortic valve replacement for severe aortic stenosis under general anesthesia. Patients were administered intravenous remimazolam infusion at 6 mg/kg/h combined with 0.25 μg/kg/min of remifentanil infusion. The primary outcome was the vasopressor dosage between the induction of anesthesia and the completion of tracheal intubation. The secondary outcomes included hemodynamic changes, bispectral index changes, and the time from the start of remimazolam infusion to loss of consciousness. We also recorded awareness during anesthesia induction and serious adverse events related to death, life-threatening events, prolonged hospitalizations, and disability due to permanent damage.

Results

Twenty patients aged 84 [79–86] (median [interquartile range]) with American Society of Anesthesiologists physical status 4 were analyzed. Ephedrine 0 [0–4] mg and phenylephrine 0.1 [0–0.1] mg were administered to 14/20 patients (3 doses in 1 patient, 2 doses in 4 patients, and one dose in 9 patients). Loss of consciousness was achieved at 80 [69–86] s after the remimazolam infusion was started. The mean arterial pressure decreased gradually after loss of consciousness but recovered immediately after tracheal intubation. The bispectral index values gradually decreased and reached < 60 at 120 s after loss of consciousness. Neither awareness during induction of anesthesia nor serious adverse events, such as severe bradycardia (< 40 bpm), life-threatening arrhythmia, myocardial ischemia, or anaphylactic reactions were observed.

Conclusions

Remimazolam could be used as an induction agent with timely bolus vasopressors in elderly patients with severe aortic stenosis.

Trial registration

UMIN Clinical Trials Registry, identifier UMIN000042318.