Efficacy of Pre-Treatment with Remimazolam on Prevention of Propofol-Induced Injection Pain in Patients Undergoing Abortion or Curettage: A Prospective, Double-Blinded, Randomized and Placebo-Controlled Clinical Trial

Comparison of the safety of remimazolam and propofol during general anesthesia in elderly patients: systematic review and meta-analysis

Background

Remimazolam is a novel sedative drug approved for procedural sedation and general anesthesia. Clinical trials have already explored its use in elderly patients for general anesthesia. For elderly patients with declining physical and physiological function, anesthesia safety is crucial. Most current clinical studies compare the safety of remimazolam and propofol, though the results are inconsistent. Therefore, we conducted a meta-analysis to compare the safety of remimazolam and propofol in general anesthesia for elderly patients.

Methods

We systematically searched the PubMed, Cochrane Library, Embase, and Web of Science databases for all published randomized controlled trials comparing remimazolam and propofol for general anesthesia in elderly patients. We synthesized data from eligible studies using relative risk or mean difference, and analyzed differences in hemodynamic stability and adverse effects between the two drugs. Data extraction and quality assessment were performed independently by two researchers.

Results

Eight randomized controlled trials involving 571 participants were included. Compared to propofol, remimazolam was associated with a lower incidence of hypotension (RR = 0.51, 95% CI: [0.33, 0.81], I 2 = 18%, p = 0.3 > 0.1) and bradycardia (RR = 0.56, 95% CI: [0.31, 1.02], Z = 1.88, p = 0.06 < 0.05). The mean arterial pressure after induction was higher in the remimazolam group (WMD = 3.95, 95% CI: [3.197, 9.498], Z = 3.95, p < 0.00001). The remimazolam group had a higher heart rate (HR) after induction compared to the propofol group (WMD = 7.89, 95% CI: [-2.39, 18.17], Z = 1.5, p = 0.13 > 0.05), but this result was not statistically significant. Among other secondary outcomes, the remimazolam group had lower incidences of injection site pain, nausea and vomiting, and hypoxemia compared to the propofol group, and also had a shorter extubation time.

Conclusion

In this meta-analysis, compared to propofol, remimazolam reduced the incidence of hypotension, bradycardia, and injection site pain during general anesthesia in elderly patients. The mean arterial pressure (MAP) and heart rate (HR) were more stable after induction. Remimazolam may be a safer sedative for elderly patients.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024516950, CRD42024516950.

Potential role of remimazolam in alleviating bone cancer pain in mice via modulation of translocator protein in spinal astrocytes

Bone cancer pain (BCP) is a complex clinical challenge, with current treatments often falling short of providing adequate relief. Remimazolam, a benzodiazepine receptor agonist recognized for its anxiolytic effects, has emerged as a potential agent in managing BCP. This study explores the analgesic properties of remimazolam and its interaction with the translocator protein (TSPO), previously known as the peripheral benzodiazepine receptor, in spinal astrocytes. In the context of BCP, previous research has indicated that TSPO expression in spinal astrocytes may serve a protective regulatory function in neuropathic pain models. Building on this, the BCP mice received various doses of remimazolam on the 15th day post-inoculation, and pain behavior was assessed over time. The results showed that BCP induced an upregulation of TSPO and astrocyte activation in the spinal dorsal horn, alongside increased extracellular signal-regulated kinase (ERK) signaling and inflammatory cytokine expression. Remimazolam administration resulted in a dose-dependent reduction of pain behaviors, which corresponded with a decrease in both ERK pathway activation and inflammatory factor expression. This suggests that remimazolam's analgesic effects are mediated through its action as a TSPO agonist, leading to the attenuation of neuroinflammation and pain signaling pathways. Importantly, the analgesic effects of remimazolam were reversed by the TSPO antagonist PK11195, underscoring the pivotal role of TSPO in the drug's mechanism of action. This reversal also reinstated the heightened levels of ERK activity and inflammatory mediators, further confirming the involvement of TSPO in the modulation of these pain-related processes. These findings open new avenues for the therapeutic management of bone cancer pain, positioning remimazolam as a promising candidate for further investigation and development.

Actions of remimazolam on inhibitory transmission of rat spinal dorsal horn neurons

Remimazolam is an ultra-short benzodiazepine that acts on the benzodiazepine site of γ-aminobutyric acid (GABA) receptors in the brain and induces sedation. Although GABA receptors are found localized in the spinal dorsal horn, no previous studies have reported the analgesic effects or investigated the cellular mechanisms of remimazolam on the spinal dorsal horn. Behavioral measures, immunohistochemistry, and in vitro whole-cell patch-clamp recordings of dorsal horn neurons were used to assess synaptic transmission. Intrathecal injection of remimazolam induced behavioral analgesia in inflammatory pain-induced mechanical allodynia (six rats/dose; p < 0.05). Immunohistochemical staining revealed that remimazolam suppressed spinal phosphorylated extracellular signal-regulated kinase activation (five rats/group, p < 0.05). In vitro whole-cell patch-clamp analysis demonstrated that remimazolam increased the frequency of GABAergic miniature inhibitory post-synaptic currents, prolonged the decay time (six rats; p < 0.05), and enhanced GABA currents induced by exogenous GABA (seven rats; p < 0.01). However, remimazolam did not affect miniature excitatory post-synaptic currents or amplitude of monosynaptic excitatory post-synaptic currents evoked by Aδ- and C-fiber stimulation (seven rats; p > 0.05). This study suggests that remimazolam induces analgesia by enhancing GABAergic inhibitory transmission in the spinal dorsal horn, suggesting its potential utility as a spinal analgesic for inflammatory pain.

ED50 of remimazolam combined with different doses butorphanol for first trimester artificial abortion

Introduction

Remimazolam (RMZ) is a novel intravenous sedative drug of ultra-short benzodiazepine. The optimal dose of RMZ plus butorphanol for sedation during first trimester artificial abortion is unknown. Therefore, the present study aimed to evaluate the median effective dose (ED50) of RMZ combined with different doses of butorphanol on the sedative effect for first-trimester artificial abortion.

Methods

Sixty-one female patients were randomly assigned to Group B10 (31 patients) and Group B15 (30 patients). RMZ was administered 5 min after IV butorphanol at doses of 10 μg/kg (Group B10) and 15 μg/kg (Group B15). Cervical dilatation at the time of using a cervical dilating rod, if the patient has body movement and affects the gynecologist's operation, we define it as "Ineffective." Therefore, the dose of RMZ was increased in the next patient. Otherwise, it was defined as "Effective," and the dose of RMZ was reduced in the next patient. According to the pre-experiment, the first dose of RMZ in the first patient was 0.35 mg/kg, and the adjacent geometric dose ratio was 0.9. The centered isotonic regression was performed to determine the ED50 of RMZ. The total RMZ dose administered, recovery time, and anesthesia-related adverse events were all recorded.

Results

The ED50 (90% CI) of RMZ was 0.263 (0.215-0.310) mg/kg in Group B10, and 0.224 (0.191-0.261) mg/kg in Group B15, respectively. The recovery time in Group B10 was significantly shorter than in Group B15 (9.8 ± 2.3 vs. 12.5 ± 3.6 min, p ≤ 0.001). There was no significant difference in the incidence rate of all anesthesia-related adverse events between the two groups (p > 0.05).

Conclusion

The ED50 of RMZ combined with a 10 μg/kg or 15 μg/kg dose of butorphanol was 0.263 and 0.224 mg/kg during painless first trimester artificial abortion. However, RMZ combined with a 10 μg/kg dose of butorphanol seems to have a shorter recovery time.

Clinical trial registration

https://www.chictr.org.cn/bin/project/edit?pid=166623.

Remimazolam versus propofol for sedation in gastrointestinal endoscopy and colonoscopy within elderly patients: a meta-analysis of randomized controlled trials

PURPOSE

Propofol has become the sedative of choice for endoscopy and colonoscopy. However, it has shown associations with various adverse effects, specifically in the geriatric population. In contrast, remimazolam is a novel benzodiazepine, demonstrating a superior clinical safety profile. Hence, this systematic review and meta-analysis aims to clarify the efficacy and safety of remimazolam versus propofol in elderly patients (≥ 60 years) undergoing gastrointestinal endoscopic and colonoscopy procedures.

METHODS

Electronic databases including PubMed, Cochrane Library, ScienceDirect, and Google Scholar were explored from inception till January 7, 2024. The Cochrane Risk of Bias Tool for Randomized Controlled Trials (RoB-2) was utilized to evaluate the quality of each included study reported in this meta-analysis.

RESULTS

Seven randomized control trials were included, resulting in the pooling of 1,466 patients (remimazolam: 731 patients; propofol: 735 patients). Propofol demonstrated a significantly lower time to loss of consciousness (P < 0.00001, 4 studies, 784 patients) and a greater sedation success after first dose (P = 0.05, 5 studies, 1,271 patients). Remimazolam reported a significantly lower risk of bradycardia (P = 0.02, 5 studies, 1,323 patients), hypoxemia (P < 0.00001, 6 studies, 1,389 patients), and pain on injection site (P < 0.00001, 5 studies, 1,184 patients). No statistically significant differences in sedation time, number of supplemental doses, procedural parameters, and other adverse outcomes were reported.

CONCLUSION

As per the results of our analyses, propofol demonstrated comparatively superior efficacy, however, remimazolam demonstrated comparatively superior safety. The debatable evidence generated from this meta-analysis may not currently be powerful enough to advocate for the use of remimazolam in elderly patients undergoing gastrointestinal procedures; hence, further comprehensive studies are necessary in order to arrive at a robust conclusion.

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 ).

The safety of remimazolam versus propofol in gastroscopic sedation: a meta-analysis

BACKGROUND

This meta-analysis was designed to compare the safety and efficiency of remimazolam with those of propofol in patients undergoing gastroscope sedation.

METHODS

We searched PubMed, Cochrane Library, Embase, Ovid, Wanfang Database, China National Knowledge Infrastructure, SINOMED, and ClinicalTrials.gov for studies that reported on remimazolam versus propofol for gastroscope sedation from establishment to February 25, 2023. The sedative efficiency and the incidence of adverse events were assessed as outcomes. Version 2 of the Cochrane risk-of-bias assessment tool was used to assess the risk of bias. Review Manager 5.4 and STATA 17 were used to perform all statistical analyses.

RESULTS

A total of 26 randomized controlled trials involving 3,641 patients were included in this meta-analysis. The results showed that remimazolam had a significantly lower incidence of respiratory depression (risk ratio [RR] = 0.40, 95% confidence interval [CI]: 0.28-0.57; p < 0.01, GRADE high), hypoxemia (RR = 0.34, 95% CI: 0.23-0.49; p < 0.01, GRADE high), bradycardia (RR = 0.34, 95% CI: 0.23-0.51; p < 0.01, GRADE high), dizziness (RR = 0.45, 95% CI: 0.31-0.65; p < 0.01, GRADE high), injection site pain (RR = 0.06, 95% CI: 0.03-0.13; p < 0.01, GRADE high), nausea or vomiting (RR = 0.79, 95% CI: 0.62-1.00; p = 0.05, GRADE moderate), and hypotension (RR = 0.36, 95% CI: 0.26-0.48; p < 0.01, GRADE low).

CONCLUSIONS

Remimazolam can be used safely in gastroscopic sedation and reduces the incidence of respiratory depression, hypoxemia, bradycardia, injection site pain, and dizziness compared with propofol, and doesn't increase the incidence of nausea and vomiting.

[Comparison of clinical effects and safety of remidazolam and esketamine for preoperative sedation in children]

OBJECTIVE

To compare the clinical effects and safety of remiazolam and esketamine in preoperative sedation in children.

METHODS

This study was conducted among 61 children (1-4 years old) undergoing elective bilateral tonsillectomy with or without adenoidectomy under general anesthesia from January 2022 to March 2023. The children were randomized into two groups to receive preoperative sedation with intravenous administration of 0.2 mg/kg remidazolam (R group, 30 cases) or 0.5 mg/kg esketamine (S group, 31 cases). The two groups were compared for PSAS score, vital signs (MAP, SpO2, and HR), sedation score, mask acceptance score at induction, sedation onset time, postoperative recovery time, MAP and HR after induction, Ramsay sedation score after awakening, doses of propofol and remifentanil during anesthesia, emergence agitation (EA), postoperative adverse effects and negative postoperative behavioral changes (NPOBCs) on the 7th and 14th days after operation.

RESULTS

The PSAS score, sedation score, mask acceptance score at induction, MAP and HR after induction, Ramsay sedation score after awakening, propofol dose during anesthesia induction, and the incidence of EA and NPOBCs after operation were all similar between the two groups (P > 0.05). Compared with those in S group, the sedation onset time was slightly longer, the recovery time was shorter, and the doses of propofol and remifentanil for anesthesia maintenance was higher (P < 0.05) in R group. Sedation with remidazolam did not cause significant changes in MAP, SpO2 or HR (P > 0.05), while administration of esketamine significantly increased MAP and HR (P < 0.05) without obviously affecting SpO2 (P > 0.05).

CONCLUSION

In children aged 1-4 years, compared with 0.5 mg/kg esketamine, intravenous injection of 0.2 mg/kg remidazolam for preoperative sedation has a slightly longer onset time and is associated with a shorter recovery time and more stable hemodynamics, suggesting its good feasibility and safety.

Efficacy of pretreatment with remimazolam on prevention of propofol-induced injection pain in patients undergoing gastroscopy

To evaluate the efficacy of remimazolam pretreatment in preventing propofol-induced injection pain (PIP) in patients undergoing gastroscopy. One hundred and forty patients (ASA I-II, aged 18-65 years, BMI 18-28 kg/m2) who were to undergo gastroscopy were randomized into either a saline group (group S) or a remimazolam group (group R) (n = 70 for each) on a computer-generated random number basis. The patients in group S received normal saline (0.1 ml/kg) and those in group R were administered remimazolam (0.1 mg/kg) via intravenous infusion for 60 s. 30 s after the injection of normal saline or remimazolam, patients received intravenously propofol (0.5 ml/s) until loss of consciousness. A different anesthesiologist who was unaware of the pretreatment was responsible for maintaining the outcome. The primary endpoint of our study was the incidence of PIP, which was measured using a 4-point scale. Secondary endpoints include the intensity of PIP, vital signs, characteristics of surgery and recovery, and adverse events. The incidence of PIP was significantly lower in group R than in group S (13 vs 51%, p < 0.001), and a lower percentage of patients presented with moderate PIP (3 vs 20%, p < 0.001). Moreover, lower consumption of propofol, shorter recovery time, and greater patient satisfaction were observed in group R than in group S. Pretreatment with remimazolam can effectively reduce the incidence and intensity of PIP in gastroscopy and shorten the recovery time without severe adverse effects.Clinical Trials Registration: Trial Registration: Chinese Clinical Trial Registry (identifier: ChiCTR2200063793). Registry time: 16/09/2022. Registry name: Efficacy of Pre-Treatment with Remimazolam on Prevention of Propofol-Induced Injection Pain in Patients Undergoing Gastroscopy. The date of patient enrollment began from 2022-9-17 to 2022-10-10. The link to the registration: https://www.chictr.org.cn/showproj.html?proj=176004 .

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 .

Drug-drug interaction study of ciprofol and sodium divalproex: Pharmacokinetics, pharmacodynamics, and safety in healthy Chinese subjects

Ciprofol (also known as HSK3486) is a promising intravenous anesthetic candidate derived from propofol and independently developed by Haisco Pharmaceutical Group Co., Ltd. (Chengdu, China). Compared with propofol, ciprofol has the potential to reduce the dose required and the associated risks. Ciprofol is extensively metabolized in vivo, and its interaction with other concurrently administered drugs during clinical application is worthy of attention. Therefore, an open-label, two-stage sequential study was performed in healthy subjects who received either a single administration of ciprofol injection or ciprofol injection after oral administration of sodium divalproex. The aim of the study was to evaluate the effects of sodium divalproex on ciprofol with respect to pharmacokinetics, pharmacodynamics, and safety, thus providing a basis for the rational clinical use of ciprofol and sodium divalproex.

Remimazolam versus propofol in combination with esketamine for surgical abortion: A double-blind randomized controlled trial

Remimazolam is a new benzodiazepine with a short half-life, good efficacy, and safety profiles in general anesthesia. Combining esketamine with propofol (P + E) could reduce propofol consumption and injection pain. It is, however, unclear if a low dose of remimazolam co-administrated with esketamine (R + E) is comparable to the increasingly used P + E for surgical abortion with general anesthetic. We conducted a double-blind randomized controlled trial to compare the efficacy and safety of R + E and P + E. Two hundred patients scheduled for a surgical abortion were randomized to receive remimazolam 0.3 mg/kg plus esketamine 0.3 mg/kg (R + E), and propofol 2 mg/kg plus esketamine 0.3 mg/kg (P + E). Sedative effectiveness was evaluated by measuring the time to lose consciousness (LOC), recovery time, and successful sedation rate. Safety was assessed by hemodynamics and adverse events during and postoperation. The time to LOC and recovery time in R + E was 5 s shorter and 1 min longer than that in P + E, respectively (both p < 0.001). Success sedation rate did not differ between groups (p = 0.73). Bradycardia incidence and injection site pain were less frequent in the R + E group than that in the P + E group. More rash was observed in the R + E group compared with the P + E group (32% vs. 5%, p < 0.001), but all were mild (only chest rash) and resolved subsequently. Low dose of remimazolam when combined with esketamine has favorable profiles with rapid onset and recovery, but mild hemodynamic side effects and adverse events. It can be used as an alternative for surgical abortion with general anesthetic.

The safety and efficacy of remimazolam tosylate combined with propofol in upper gastrointestinal endoscopy: A multicenter, randomized clinical trial

INTRODUCTION

Hypotension is the most common adverse event under propofol-mediated sedation and is possible to cause varying degrees of damage to patients. Whereas remimazolam has a poorer sedative effect than propofol.

AIM

The aim of this study was to explore the advantages of the combination of remimazolam tosylate and propofol.

METHODS

304 patients were divided into the remimazolam tosylate group (RT group), the propofol group (P group), and the remimazolam tosylate plus propofol group(R+T group). The primary outcome was the incidence of hypotension. Secondary outcomes included the results of sedation and recovery. The safety results mainly include the incidence of Hypotension, adverse respiratory events, postoperative nausea and vomiting, hiccup, cough, body movement and bradycardia.

RESULTS

The incidence of hypotension was 56.7% in the P group, 12.6% in the RT group, and 31.3% in the R+P group, three groups of pairwise comparisons showed statistical differences, with P< 0.001. The incidence of body movement was significantly higher in the RT group (26.1%) than in the P group (10.3%) and the R+P group (12.5%), P = 0.004. The endoscopist satisfaction was higher in the P (3.87±0.44) and R+P (3.95±0.22)groups than in the RT(3.53±0.84) group. The incidence of adverse events, in descending order, was P group, RT group, and R+P group (93.8%vs.61.3%vs.42.7%).

CONCLUSION

Co-administration had fewer adverse events than propofol monotherapy, also had a better sedative effect and higher endoscopist satisfaction than remimazolam monotherapy.

TRIAL REGISTRATION

Clinical trial registration number: NCT05429086.

Evaluating efficacy and safety of sub-anesthetic dose esketamine as an adjuvant to propofol/remifentanil analgosedation and spontaneous respiration for children flexible fibreoptic bronchoscopy: a prospective, double-blinded, randomized, and placebo-controlled clinical trial

Background: Flexible fiberoptic bronchoscopy (FFB) for children is widely performed under sedation. Currently, the optimal sedation regimen remains unclear. Esketamine is an N-methyl-D-aspartic acid (NMDA) receptor antagonist, which has stronger sedative and analgesic effects and exerts less cardiorespiratory depression than other sedatives. The purpose of this study was to evaluate whether a subanesthetic dose of esketamine as an adjuvant to propofol/remifentanil and spontaneous ventilation compared with control reduces the procedural and anesthesia-related complications of FFB in children. Materials and methods: Seventy-two children ≤ 12 years of age who were scheduled for FFB were randomly assigned, in a 1:1 ratio, to the esketamine-propofol/remifentanil (Group S, n = 36) or to the propofol/remifentanil group (Group C, n = 36). All children were retained spontaneous ventilation. The primary outcome was the incidence of oxygen desaturation (respiratory depression). Perioperative hemodynamic variables, blood oxygen saturation (SPO₂), end-tidal partial pressure of carbon dioxide (PetCO₂), respiratory rate (R), and the Bispectral index (BIS), induction time, procedural time, recovery time, the time to the ward from the recovery room, consumption of propofol and remifentanil during the procedure and the appearance of adverse events, including paradoxical agitation following midazolam administration, injection pain, laryngospasm, bronchospasm, PONV, vertigo, and hallucination were also compared. Results: The incidence of oxygen desaturation was significantly lower in Group S (8.3%) compared to Group C (36.1%, p = 0.005). The perioperative hemodynamic profile including SBP, DBP, and HR were more stable in Group S than that in Group C (p < 0.05). Consumption of propofol and remifentanil was lower in Group S than in Group C (p < 0.05). Furthermore, PAED scores, cough scores and injection pain were lower in the Group S than in Group C (p < 0.05). The recovery time of Group S was slightly longer than that of Group C (p < 0.05). Nobody happened paradoxical agitation following midazolam administration, PONV, vertigo, and hallucinations in both groups (p > 0.05). Conclusion: Our findings indicate that a subanesthetic dose of esketamine as an adjuvant to propofol/remifentanil and spontaneous respiration is an effective regimen for children undergoing FFB. Our findings will provide a reference for clinical sedation practice during these procedures in children. Clinical Trail Registration: Chinese clinicaltrials.gov registry (identifier: ChiCTR2100053302).

Effect of Remimazolam Tosilate on Respiratory Depression in Elderly Patients Undergoing Gastroscopy: A Multicentered, Prospective, and Randomized Study

Background

Remimazolam tosilate (RT) is a new type of γ-aminobutyric acid subtype A (GABA_A) receptor agonist, having the possibility to be an ideal sedative drug for procedural sedation. At present, there are few studies on the effect of RT on respiratory depression in elderly patients. We aimed to evaluate the effect of RT on respiratory depression in elderly patients undergoing gastroscopy.

Methods

This prospective, randomized, single-blinded trial recruited patients from eight centers in China between May 2022 and July 2022. A total of 346 elderly patients undergoing gastroscopy were randomly divided into RT group (0.2 mg/kg) or propofol group (1.5 mg/kg), respectively. The primary outcome was the incidence of respiratory depression. Secondary outcomes include the incidence of sedative-related adverse events, the success rate of sedation, time to fully alert, time to loss of consciousness (LOC), time to ready for discharge, as well as the the patients, endoscopists and anethetists' satisfaction.

Results

The incidence of respiratory depression was significantly reduced in the RT group compared with the propofol group (9.8% vs 17.9%, P=0.042). The time of LOC and fully alert in the RT group were longer than that in the propofol group (P < 0.05). The incidences of hypotention (50.9% vs 32.4%, P=0.001) and hypotension requiring treatment (5.8% vs 1.7%, P=0.031) were significantly higher in the propofol group than that in the RT group. The incidence and severity of injection pain were more frequently recorded in the propofol group than that in the RT group (40.5% vs 12.1%, P<0.05). There were no statistically significant differences between the two groups in terms of sedation success rates, time to ready for discharge, endoscopists and anethetists' satisfaction and other sedative-related adverse events.

Conclusion

RT may be a suitable alternative sedative agent for elderly patients undergoing gastroscopy due to its safety profile.

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.

Efficacy and Safety of the Remimazolam-Alfentanil Combination for Sedation During Gastroscopy: A Randomized, Double-blind, Single-center Controlled Trial

PURPOSE

Propofol infusion is a popular single drug of choice for sedation in the gastrointestinal endoscopy suite. Drug combinations are more beneficial than single-drug regimens in gastroscopy sedation. However, the cardiopulmonary complications of propofol sedation raise concern. Remimazolam is a novel, ultra-short-acting benzodiazepine sedative, and alfentanil is a weak opioid. During endoscopic procedures, remimazolam is an effective and safe sedative procedure. No synergistic effect has been reported when remimazolam was combined with alfentanil in gastroscopy sedation. Here, we evaluated the effective dose, sedative efficacy, and safety of the remimazolam-alfentanil combination in gastroscopy sedation and compared the results with those of the propofol-alfentanil combination.

METHODS

This study was conducted in two parts. In Part 1, Dixon's up-and-down method (sequential distribution) was adopted for determining the 95% effective dose (ED95) (95% CI) and 95% CI of remimazolam combined with 5 µg/kg alfentanil. In Part 2, after obtaining the predictive remimazolam ED95, 161 patients were randomized into the remimazolam group (remimazolam-alfentanil) and the propofol group (propofol-alfentanil). The effectiveness of the drug combinations was measured according to successful sedation parameters. Changes in vital signs and the appearance of adverse events were used to assess the safety of drug combinations. Evaluation of patient and physician satisfaction was included as quality indicators of treatment.

RESULTS

Baseline demographic and clinical characteristics were comparable between the 2 parts of the study. The ED95 of remimazolam in inhibiting a positive response to gastroscopy placement into the pharyngeal cavity was 0.33 mg/kg (95% CI, 0.289 to 1.023). The procedure success rate was 97.53% in the remimazolam group and 97.50% in the propofol group. The difference in the success rate of the procedure between the remimazolam and propofol groups was 0.03% (95% CI, -2.5 to 2.4). However, the incidence of injection pain, hypotension, respiratory depression, and dizziness was lower in the remimazolam group compared with the propofol group (P < 0.05). Furthermore, patients from the propofol group were more likely to be drowsy, and their work efficiency was reduced the day after leaving the hospital, whereas patients in the remimazolam group were less affected (P < 0.05).

IMPLICATIONS

The ED95 of remimazolam was 0.33 mg/kg when it was combined with alfentanil (5 µg/kg) for gastroscopy sedation. The sedation strategy of remimazolam-alfentanil has noninferior efficacy, fewer adverse effects, and a better postoperative recovery process than propofol-alfentanil for patients undergoing gastroscopy. Chinese Clinical Trials Registry identifier: ChiCTR2100051565.

Effect of different doses of esketamine compared with fentanyl combined with propofol on hypotension in patients undergoing painless abortion surgery: a prospective, randomized, double-blind controlled clinical trial

Background

Opioids analgesics commonly used in abortion procedures are associated with respiratory and circulatory depression. Esketamine is a N-methyl-D-aspartate receptor (NMDA) antagonist and a common analgesic. The drug has several advantages including rapid onset and offset and it causes minimal cardiorespiratory depression. However, studies have not explored the effects of esketamine in patients undergoing painless abortion surgery. Therefore, the present study sought to evaluate the effect of different doses of esketamine compared with the effect of fentanyl on incidence of perioperative hypotension in patients undergoing painless abortion surgery and to explore the optimal esketamine dose for this population.

Methods

A total of 178 female patients undergoing painless abortion surgery were enrolled to the current study. The patients were aged 18–45 years, had a body mass index (BMI) of 18–28 kg m^− 2 and a class I or II physical status as determined using the American Society of Anesthesiologists (ASA) system. Patients were randomly assigned to four groups as follows: group F (n = 45) in which patients underwent intravenous (IV) administration of 1 μg kg^− 1 fentanyl followed by IV administration of 2 mg kg^− 1 propofol, and group EL, group EM and group EH (n = 45, 44, 44) with patients receiving IV administration of 0.2 mg kg^− 1, 0.25 mg kg^− 1, 0.3 mg kg^− 1 esketamine, respectively, followed by IV administration of 2 mg kg^− 1 propofol. The primary outcome of the study was the incidence of hypotension whereas secondary outcomes included incidence of adverse events, perioperative changes of vital signs, anesthesia induction time, recovery time and dischargeable time, propofol addition, as well as patient, surgeon and anesthesiologist satisfaction levels.

Results

The findings showed that the incidence of hypotension was significantly lower in subjects in group EL, group EM and group EH (0, 0, 0%) relative to the incidence in patients in group F (20%) (χ² = 19.648; P = 0.000). In this study, the incidence of hypoxia of subjects in group EL, group EM and group EH (0, 2.3, 2.3%) was significantly lower compared with that of patients in group F (11.1%) (χ² = 8.622; P = 0.035). The findings indicated that the incidence of somatic motor reactions was significantly lower in participants in group EM and group EH (9.1, 4.5%) relative to that of patients in group F and group EL (26.7, 15.6%) (χ² = 10.254; P = 0.016). The results showed that the incidence of nausea and vomiting and potential psychiatric symptoms were significantly higher in patients in group EH (15.9, 11.4%) compared with that of participants in group F (2.2, 0%), group EL (4.4, 0%) and group EM (2.3, 2.3%) (χ² = 7.493; P = 0.038 and χ² = 8.248; P = 0.003). In this study, the mean arterial pressure (MAP) and heart rate (HR) of subjects in group EL, group EM and group EH were more stable compared with that of patients in group F. Frequency of the additional propofol dose was markedly less in group EM and EH (26.7%, 17,8%) compared with that in group F and EL (9.1, 4.5%) (χ² = 10.254; P = 0.016). The findings indicated that the dischargeable time was significantly shorter for patients in group EM compared with that of subjects in group F, group EL and group EH.

Conclusions

The findings of the present study showed that single-dose esketamine (0.25 mg kg^− 1) effectively decreased incidence of hypotension and total adverse events and reduced the frequency of additional propofol dose required for patients undergoing painless abortion with preservation of physician-patient satisfaction.

Esketamine prevents propofol-induced injection pain: Randomized controlled trial

Background: Propofol is widely used during anesthesia. However, propofol-induced injection pain (PIP) is considered an unpleasant perioperative outcome. This study aimed to investigate the efficacy of a mixture of esketamine and propofol in preventing propofol injection pain in patients undergoing general anesthesia.

Methods: This was a prospective, double-blind, multicenter, and randomized controlled trial. We included 252 adult patients with the American Society of Anesthesiologists physical status I to II who underwent surgery under general anesthesia. Patients were randomly allocated in a 1:1:1:1 ratio to four groups (n = 63 per group). Group NS received a mixture of 1% propofol (20 ml) and 0.9% normal saline (1 ml), group ESK-4 received a mixture of 1% propofol (20 ml) and esketamine 4 mg (diluted with 0.9% normal saline, 1 ml), group ESK-12 received a mixture of 1% propofol (20 ml) and esketamine 12 mg (diluted with 0.9% normal saline, 1 ml), and group ESK-20 received a mixture of 1% propofol (20 ml) and esketamine 20 mg (diluted with 0.9% normal saline, 1 ml) as sedative drugs during anesthesia. The primary outcome was the incidence and distribution of different degrees of PIP. The secondary outcomes were vital signs, characteristics of surgery and anesthesia, and adverse events.

Results: The incidence of PIP in group ESK-20 (33.3%) was significantly lower than that in groups NS, ESK-4, and ESK-12 (63.3%, 62.2%, and 49.1%, respectively; p &lt; 0.01). The incidence of moderate PIP in group NS (33.3%) and group ESK-4 (22.6%) was higher than that in groups ESK-12 (7.5%) and ESK-20 (6.7%). The incidence of severe PIP in group NS (6.7%) and group ESK-4 (9.4%) was higher than that in groups ESK-12 (1.9%) and ESK-20 (0%). There were no differences in the vital signs, characteristics of surgery and anesthesia, or adverse events between the groups.

Conclusion: Our results indicated that the esketamine–propofol admixture reduced the incidence of PIP in patients undergoing general anesthesia without severe side effects.