Prevention of postoperative nausea and vomiting after gynaecological day surgery under remimazolam general anesthesia: a randomized double-blind controlled study

Remimazolam: its clinical pharmacology and evolving role in anesthesia and sedation practice

PURPOSE OF REVIEW

Remimazolam is a novel benzodiazepine anesthetic/sedative, designed as a rapidly metabolized carboxylic acid. Since its recent launch, the role of remimazolam in modern anesthesia and sedation practice is still evolving. This review aims to outline the clinical pharmacology and clinical utility of remimazolam to elucidate its potential advantages and limitations.

RECENT FINDINGS

Remimazolam is "short-acting" but not ultra-short-acting compared with propofol based on context-sensitive decrement times. But compared to propofol, the availability of the benzodiazepine antagonist, flumazenil, is considered an advantage, particularly in certain emergency situations such as in patients with difficult airways. However, because flumazenil is shorter acting than remimazolam when remimazolam accumulates or is present in a high concentration, the reappearance of remimazolam sedation may occur after the initial reversal of anesthesia/sedation from flumazenil administration. Although it is beneficial that remimazolam causes less respiratory depression and hypotension than propofol, serious respiratory depression and hypotension can still occur. Remimazolam administration causes minimal or no pain on injection. Remimazolam is associated with less postoperative nausea and vomiting than inhaled anesthetics, but propofol is clearly superior in this regard. The anesthetic/sedative effects may be prolonged by severe hepatic impairment; remimazolam tolerance can occur in long-term benzodiazepine users.

SUMMARY

Remimazolam may be beneficial to use in procedural sedation and general anesthesia for patients with difficult airways or hemodynamic instability. Further clinical studies with remimazolam are warranted to identify the potential benefits in other settings and patient populations.

Effect of Prophylactic Tropisetron on Post-Operative Nausea and Vomiting in Patients Undergoing General Anesthesia: Systematic Review and Meta-Analysis with Trial Sequential Analysis

This systematic review and meta-analysis of randomized controlled trials (RCTs) with trial sequential analysis (TSA) aimed to comprehensively evaluate and compare the efficacy of the prophylactic administration of tropisetron in the prevention of the incidence of post-operative nausea and vomiting (PONV) in patients undergoing surgery under general anesthesia. This study was registered with PROSPERO (CRD42024372692). RCTs comparing the efficacy of the perioperative administration of tropisetron with that of a placebo, other anti-emetic agents, or a combination of anti-emetic injections were retrieved from the databases of Ovid-MEDLINE, Ovid-EMBASE, the Cochrane Central Register of Controlled Trials, and Google Scholar. The frequency of rescue anti-emetic use (RA) and the incidence of PON, POV, and PONV (relative risk [RR]: 0.718; 95% confidence interval [CI] 0.652-0.790; I2 = 0.0, RR: 0.587; 95% CI 0.455-0.757; I2 = 63.32, RR: 0.655; 95% CI 0.532-0.806; I2 = 49.09, and RR: 0.622; 95% CI 0.552-0.700; I2 = 0.00, respectively) in the tropisetron group were lower than those in the control group; however, the incidence of complete response (CR) was higher in the tropisetron group (RR: 1.517;95% CI 1.222-1.885; I2 = 44.14). TSA showed the cumulative Z-curve exceeded both the conventional test and trial sequential monitoring boundaries for RA, PON, POV, and PONV between the tropisetron group and the control group. Thus, the prophylactic administration of tropisetron exhibited superior efficacy in the prevention of PON, POV, and PONV. Furthermore, a lower incidence of RA and a higher incidence of CR were observed with its use.

Clinical Study of Flumazenil Antagonizing Remimazolam on Nausea and Vomiting After Gynecologic Day Surgery

Purpose

To evaluate the effect of flumazenil antagonizing remimazolam on postoperative nausea and vomiting (PONV) after gynecologic day surgery.

Patients and Methods

141 cases of gynaecological daycase surgery patients in Weifang People's Hospital were selected, randomized into group F (flumazenil group, 71 cases) and group C (control group, 70 cases). Dexamethasone 5 mg, flurbiprofen axetil 50 mg, and droperidol 1 mg were given intravenously before induction of anesthesia in both groups. Anesthesia induction: Remimazolam 0.25mg / kg was injected within 1 minute. After the patient fell asleep, mivacurium chloride 0.2mg / kg was injected for 30 seconds and alfentanil 20ug / kg was injected for 30 seconds. Anesthesia maintenance: Remimazolam 1mg/kg/h and alfentanil 40ug/kg/h were continuously pumped by micro pump. Stopping the injection of remimazolam and alfentanil at the end of the operation. Flumazenil 0.2 mg was given to antagonize remimazolam in group F after 1 minute. Group C was given an equal volume of saline. The incidence of PONV in the postoperative PACU and over a 24-hour period, patient awakening time, and general patient information were recorded.

Results

The incidence of PONV in both groups within 24 hours was 50.70% in group F was significantly higher than 32.86% in group C. The difference was statistically significant (P < 0.05). The incidence of PONV in the PACU was 5.6% in group F and 8.6% in group C. The difference was not statistically significant (p > 0.05).

Conclusion

Flumazenil antagonism of remimazolam increases the incidence of PONV within 24 hours in gynecologic day surgery patients and has no significant effect on the incidence of PONV in the PACU.

Propofol combined with alfentanil for general anesthesia in vocal cord polypectomy under suspension laryngoscopy

OBJECTIVE

To investigate the clinical effect of propofol combined with alfentanil in vocal cord polypectomy under suspension laryngoscopy.

METHODS

A total of 308 patients undergoing vocal cord polypectomy under suspension laryngoscopy in the First Affiliated Hospital of Nanchang University were included in this prospective study, and the patients were randomly divided into an observation group and a control group. Patients in the observation group received alfentanil combined with propofol, while those in the control group were anesthetized with sufentanil combined with propofol. The heart rate (HR), mean arterial pressure (MAP), real portfolio project (RPP), and Steward postanesthetic recovery scores were compared between the two groups before anesthesia induction (T0), at intubation (T1), 5 min after intubation (T2), at the time of placing suspension laryngoscopy (T3), 1 min after placing the suspension laryngoscopy (T4), 1 min after extraction of support laryngoscope (T5), and 1 min after extubation (T6). In addition, the propofol dosage and peripheral plasma levels of epinephrine (E) and norepinephrine (NE) were also compared between the groups.

RESULTS

The MAP, HR, and RPP of the patients in the observation group were higher than those in the control group at T1-T5 (all P<0.05), while there was no statistical difference at T0 and T6 (all P>0.05). The Steward postanesthetic recovery scores and the propofol dosage in the observation group were lower than those in the control group. In addition, there was a statistically significant difference in the E and NE levels between the two groups after surgery (P<0.001). There was also an interaction effect between the groups and among the time points (both P<0.001).

CONCLUSION

Alfentanil can reduce the fluctuation of hemodynamics during vocal cord polypectomy under suspension laryngoscopy, and therefore improve anesthesia effect. Simultaneously, the usage of propofol was reduced, as well as the stress levels.

CLINICAL TRIAL NUMBER

ChiCTR2100054186.

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 .

Remimazolam-remifentanil causes less postoperative nausea and vomiting than remimazolam-alfentanil during hysteroscopy: a single-centre randomized controlled trial

BACKGROUND

Although the operation time of hysteroscopy is short, the incidence of postoperative nausea and vomiting is high. The aim of this study was to compare the incidence of postoperative nausea and vomiting in hysteroscopy when remimazolam is combined with remifentanil or alfentanil.

METHODS

We conducted a randomized, controlled, double-blind trial. Patients undergoing hysteroscopy were recruited and randomly assigned to either the remimazolam-remifentanil (Group RR) or the remimazolam-alfentanil group (Group RA). All patients in the two groups were started with an induction dose of remimazolam besylate 0.2 mg/kg and then maintained with a dosage of 1.0 mg/kg/h. After induction with remimazolam besylate, in Group RR, remifentanil was infused using a target-controlled infusion system with a target concentration of 1.5 ng/ml and titrated throughout the procedure. In Group RA, infusion of alfentanil was started with an initial bolus dose of 20 µg/kg over 30 s and then maintained at an initial rate of 0.16 µg/kg/min. The primary observation outcome was the incidence rate of postoperative nausea and vomiting. The secondary observation outcomes were the time to awakening, the length of stay in the PACU, the total remimazolam dose and adverse effects, such as low SpO2, bradycardia, hypotension and body movement.

RESULTS

A total of 204 patients were successfully included in this study. The incidence of postoperative nausea and vomiting in Group RR (2/102, 2.0%) was significantly lower than that in Group RA (12/102, 11.8%) (p < 0.05). There was no significant difference in the incidence of adverse events, such as low SpO2, bradycardia, hypotension and body movement, between Groups RR and RA (p > 0.05).

CONCLUSIONS

Remimazolam-remifentanil causes less postoperative nausea and vomiting than remimazolam-alfentanil in hysteroscopy.

TRIAL REGISTRATION

Clinical trial registration number: ChiCTR2100044177. Full date of the first registration: 12/03/2021.