Efficacy and Safety of Remimazolam Besylate Versus Propofol During Hysteroscopy

Single-centre Randomized Controlled Trial

Xiaoqiang Zhang; Shuang Li and Jing Liu


BMC Anesthesiol. 2021;21(156) 

In This Article


This trial was conducted to confirm the efficacy and safety of remimazolam besylate versus propofol during hysteroscopy. Based on our data, remimazolam besylate proves to be a safer alternative for anesthesia during hysteroscopy.

Throughout this study, we observed no serious adverse events or adverse reactions in the two groups that would require withdrawal from the trial. The incidence of adverse events in Group R (6/164, 3.7%) was significantly lower than that in Group P (60/164, 36.6%) (p < 0.05). Injection pain, postoperative dizziness and low SpO2 were the most common adverse events (Table 2, p < 0.05).

In a previous multicentre phase III clinical trial in China, 384 eligible patients undergoing colonoscopy were randomly divided into remimazolam and propofol groups. The remimazolam group had a lower incidence of hypotension (46 (23.71%) versus 97 (51.05%)) and respiratory depression (6 (3.09%) versus 32 (16.84%)) than the propofol group.[19] In another prospective, double-blind, randomized, multicentre study that was performed at 30 US sites to estimate the efficacy and safety of remimazolam compared with placebo and open-label midazolam in patients undergoing bronchoscopy, 5.6% of the patients in the remimazolam group had serious adverse events compared with 6.8% in the placebo group.[20] Our experiment further confirmed those results.

Injection pain is one of the most common adverse reactions of propofol in clinical practice. Remidazolam has the same sedative effect as propofol, effectively avoiding the adverse reactions of injection pain to improve patient comfort.

The duration of awakening of patients in Group R (199.0 ± 79.9 s) was longer than that in Group P (59.7 ± 1.2 s). The PACU length of stay of patients in Group R (5.44 ± 1.0 min) was shorter than that in Group P (6.3 ± 1.9 min). Although we observed some statistically differences, these differences did not have a major impact on the clinical procedures. In another multicentre phase III trial, 384 patients scheduled to undergo gastrointestinal endoscopy were randomly assigned to remimazolam and propofol groups. Researchers also found that remimazolam (5.75 min) yielded a faster recovery from sedation than propofol (6.71 min). This is a potential benefit of remimazolam over propofol.[21] It can be speculated that both remimazolam and propofol can meet the required anaesthetic depth and maintenance time for uterine cavity examination, but sedation using remimazolam can avoid the phenomenon of deep sedation observed in the propofol group and has little effect on inhibition of the central nervous system in patients.

Remimazolam has the advantages of rapid onset, a short elimination half-life, and drug metabolism that is independent of liver and kidney function;[22] moreover, it has a specific antagonist, namely, flumazenil.[23] As a benzodiazepine, remimazolam could be evaluated as an anticonvulsant and for use in intensive care sedation. Remimazolam provides effective procedural sedation with superior success rates and recovery profiles compared to midazolam.[24] At present, data comparing remimazolam with propofol are lacking. In previous studies, remimazolam was effectively and safely used in Chinese volunteers.[11,25]

There are some limitations of this study. This was a single-centre investigation, and the sample size was relatively small, which limited the statistical analysis of the two groups of patients.