Moderate sedation with single-dose remimazolam tosilate in elderly male patients undergoing transurethral resection of the prostate with spinal anesthesia: a prospective, single-arm, single-centre clinical trial

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.

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 .

Effective doses of ciprofol combined with alfentanil in inhibiting responses to gastroscope insertion, a prospective, single-arm, single-center study

BACKGROUND

Ciprofol is a novel intravenous sedative and anesthetic. Studies have shown that it features a rapid onset of action, a fast recovery time, slight inhibition of respiratory and cardiovascular functions, and a low incidence of adverse reactions. This study aims to explore the median effective dose (ED50) and the 95% effective dose (ED95) of ciprofol in inhibiting responses to gastroscope insertion when combined with a low dose of alfentanil, and to evaluate its safety, to provide a reference for the rational use of ciprofol in clinical practices.

METHODS

We included 25 patients aged 18-64 years of either sex who underwent gastroscopy under intravenous general anesthesia, with a Body Mass Index (BMI) 18-28 kg/m2, and an American Society of Anesthesiologists (ASA) grade I or II. In this study, the dose-finding strategy of ciprofol followed a modified Dixon's up-and-down method with an initial dose of 0.30 mg/kg and an increment of 0.02 mg/kg. Ciprofol was administered after intravenous injection of 7 µg/kg of alfentanil, and 2 min later a gastroscope was inserted. When the insertion response of one participant was positive (including body movement, coughing, and eye opening), an escalation of 0.02 mg/kg would be given to the next participant; otherwise, a de-escalation of 0.02 mg/kg would be administered. The study was terminated when negative response and positive response alternated 8 times. A Probit model was used to calculate the ED50 and ED95 of ciprofol in inhibiting responses to gastroscope insertion when combined with alfentanil. Patients' recovery time, discharge time, vital signs and occurrence of adverse reactions were recorded.

RESULTS

The ED50 of single-dose intravenous ciprofol injection with 7 µg/kg of alfentanil in inhibiting gastroscope insertion responses was 0.217 mg/kg, and the ED95 was 0.247 mg/kg. Patients' recovery time and discharge time were 11.04 ± 1.49 min and 9.64 ± 2.38 min, respectively. The overall incidence of adverse reactions was 12%.

CONCLUSION

The ED50 of ciprofol combined with 7 µg/kg of alfentanil in inhibiting gastroscope insertion responses was 0.217 mg/kg, and the ED95 was 0.247 mg/kg. Ciprofol showed a low incidence of anesthesia-related adverse events.

TRIAL REGISTRATION

http://www.chictr.org.cn (ChiCTR2200061727).

Safety and efficacy of remimazolam tosilate combined with low-dose fentanyl for procedural sedation in obese patients undergoing gastroscopy: study protocol for a single-centre, double-blind, randomised controlled trial

INTRODUCTION

Obese patients are susceptible to hypoxaemia during procedural sedation. Propofol combined with low-dose opioids is commonly used as a sedation strategy, but it can exacerbate hypoxaemia by causing cardiopulmonary depression and airway obstruction, especially in obese patients. Remimazolam, a novel ultra-short-acting benzodiazepine, has minimal accumulative effects and less cardiorespiratory depression. This study aims to evaluate the safety and efficacy of combining remimazolam tosilate with low-dose fentanyl as an alternative option for procedural sedation in obese patients undergoing gastroscopy.

METHODS AND ANALYSIS

This randomised controlled trial (RCT) will be conducted in the Endoscopy Centre of the First Affiliated Hospital of Xiamen University, recruiting 174 participants scheduled for painless gastroscopy with a body mass index of 30-39.9 kg×m-2. All patients will be randomly divided into two groups in a 1:1 ratio. The sedation strategy of the intervention group is remimazolam tosilate combined with fentanyl, while the control group is propofol combined with fentanyl. The primary outcome is the incidence of hypoxaemia and the secondary outcomes include the time to ambulation, need for airway manoeuvres and rescue sedation, sleep quality, the incidence of sedation failure, adverse events and the cost of sedatives. All statistical tests will be performed using IBM SPSS V.20.0 statistical software. A p value<0.05 is considered statistically significant.

ETHICS AND DISSEMINATION

This RCT was reviewed and approved by the Ethics Committee of the First Affiliated Hospital of Xiamen University (Scientific Research Ethics Review 2022, No.093). The results will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ChiCTR2200067076.

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 .

Spinal anesthesia in elective lumbar spinal surgery

Spinal anesthesia (SA) is gaining recognition as a safe and efficacious regional alternative to general anesthesia for elective lumbar surgery. However, unfamiliarity with management issues related to its use has limited the adoption of awake spine surgery, despite its benefits. Few centers in the United States routinely offer SA for elective lumbar surgery, and a comprehensive workflow to standardize SA for lumbar surgery is lacking. In this article, we examine recent literature on the use of SA in lumbar surgery, review the experience of our institution with SA in lumbar surgery, and provide a cohesive outline to streamline the implementation of SA from the perspective of the anesthesiologist. We review the critical features of SA in contemporary lumbar surgery, including selection of patients, methods of SA, intraoperative sedation, and management of several important technical considerations. We aimed to flatten the learning curve to improve the availability and accessibility of the technique for eligible patients.

Comparison of bispectral index and patient state index as measures of sedation depth during surgeries using remimazolam tosilate

BACKGROUND

The Bispectral Index (BIS) and the Patient State Index (PSI) are commonly used measures to assess intraoperative sedation depth. However, model differences lead to different results, which in turn interferes with clinicians' judgment on the depth of anesthesia. Remimazolam tosilate (RT) for injection is a new benzodiazepine used in sedation. In its clinical application, there are few effective indicators for sedation depth monitoring. To close this gap, this study aims to compare BIS and PSI in measuring the sensitivity and specificity of intraoperative RT and to explore the safety of RT for intraspinal anesthesia in elderly patients.

METHODS

This study included 40 patients undergoing elective electro-prostatectomy with intraspinal anesthesia, who were monitored by BIS and PSI simultaneously during operation. Remimazolam tosylate 0.1 mg/kg was intravenously administered after the intraspinal anesthesia when patients were in a completely painless status. Then BIS, PSI, the Modified Observer's Assessment of Alertness and Sedation (MOAA/S) scores and vital signs were observed and recorded per minute for 10 min. Pearson's correlation analysis and linear regression model were used to compare BIS and PSI sedation scores, and to test their associations with the MOAA/S score, respectively. ROC curves were drawn to compare the sensitivity and specificity of BIS and PSI. Changes of vital signs were presented as mean ± standard deviation. Perioperative liver and kidney function indicators were analyzed using a paired t-test to evaluate the safety of RT for intraspinal anesthesia in the elderly patients.

RESULTS

According to Pearson's correlation analysis, a significant (P < 0.01) correlation between BIS and PSI was found when used to monitor intraoperative sedation of RT (r = 0.796). Significant associations between BIS and MOAA/S (r = 0.568, P < 0.01), and between PSI and MOAA/S (r = 0.390, P < 0.01) were also found. The areas under the ROC curves of BIS and PSI were 0.801 ± 0.022 and 0.734 ± 0.026, respectively, suggesting that both measures may predict patients' state of consciousness and BIS was more accurate than PSI. Vital signs remained stable throughout the study. No abnormal changes of clinical significance were found based on laboratory test results of liver and kidney function.

CONCLUSION

BIS and PSI are strongly associated for monitoring the sedation of RT intraoperatively. Both methods can accurately reflect sedation depth. According to correlation analyses with MOAA/S scale and ROC curves, BIS is more accurate than PSI during such intraoperative monitoring. In addition, RT can be safely used in elderly patients under intraspinal anesthesia for supportive sedation, with stable vital signs and sound kidney and liver safety profiles.

TRIAL REGISTRATION

http://www.chictr.org.cn (ChiCTR2100051912).

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.