Determining the 90% Effective Dose of Remimazolam in Terms of Inhibiting Responses to Upper Gastrointestinal Endoscopy Insertion in Elderly Patients: A Double-Blind Study Utilizing a Biased Coin Up-and-Down Sequential Method

Abstract

Background: Remimazolam is a good option for anesthesia in elderly patients undergoing gastrointestinal (GI) endoscopy procedures because of its rapid onset, short metabolic duration, and extensively documented safety profile. However, the accurate clinical dosage of these agents has yet to be determined. The objective of this research was to examine the efficacy of the 90% effective dose (ED90) of remimazolam in suppressing the responses of elderly patients during the insertion phase of upper GI endoscopy.

Methods: We enrolled 53 individuals aged 65– 85 years who underwent upper GI endoscopy and were anesthetized with an intravenous bolus of remimazolam. After initiating an initial dose of 0.35 mg/kg remimazolam, subsequent adjustments were made on the basis of the patient’s response, employing an up-and-down sequential allocation using a biased coin design. The primary outcome was the ED90 of the remimazolam infusion for inhibiting the response to upper GI endoscope insertion. Adverse reactions during the perioperative period were observed and recorded.

Results: The ED90 of remimazolam for upper GI endoscope insertion in elderly patients was 0.400 mg/kg (95% CI = 0.348–0.524). Stable circulation was maintained in all patients, and no serious adverse events were observed during sedation. Satisfaction levels were high among the participants: Patients reported a satisfaction score of 4.98 ± 0.14 points, anesthesiologists rated their satisfaction at 4.91 ± 0.35 points, and endoscopists expressed a satisfaction level of 4.89 ± 0.38 points (based on a total score of 5 points, with a minimum of 1 point).

Conclusion: Administration of remimazolam for upper GI endoscopy in elderly patients was found to be both safe and effective. A single intravenous bolus at an ED90 dose of 0.556 mg/kg effectively suppressed the response to the procedure.

Trial Registration: Chinese Registry of Clinical Trials: ChiCTR2200062535