Determination of the 90% Effective Dose of Remimazolam in Combination With a Low Dose of Alfentanil for Suppressing Responses During Upper Gastrointestinal Endoscopy Insertion

Remimazolam has shown safety and efficacy in providing sedation during gastroscopy, but research on its specific clinical dosage is limited. This study aimed to determine the 90% effective dose (ED 90 ) of remimazolam when used with a low dose of alfentanil for inducing sedation in adult patients undergoing gastroscopy. Fifty adult participants underwent upper gastrointestinal (GI) endoscopy with anesthesia via intravenous boluses of remimazolam and alfentanil (4 μg/kg). The initial remimazolam dose was 0.2 mg/kg, adjusted using the biased coin up‐and‐down (BCUD) sequential method. The ED 90 of remimazolam, administered with 4 μg/kg alfentanil, was found to be 0.2375 mg/kg (95% CI: 0.1500–0.2725). Hemodynamics remained stable, with no significant adverse events and high satisfaction scores from patients, anesthesiologists, and endoscopists (4.90 ± 0.043, 4.92 ± 0.039, and 4.92 ± 0.039, respectively, on a 5‐point scale). The combination of remimazolam and low‐dose alfentanil is safe and effective for adult upper GI endoscopy. Trial Registration: Chinese Registry of Clinical Trials: ChiCTR2200062535