Effective Dose of Oliceridine Fumarate Co-Administered with Remimazolam in Suppressing Gastroscope Insertion Responses for Adults.

Objective: To determine the 50% effective dose (ED50) and 95% effective dose (ED95) of oliceridine in suppressing gastroscope insertion responses during painless gastroscopy when combined with 0.3 mg/kg remimazolam. Methods: This prospective study enrolled 52 patients scheduled for elective painless gastroscopy. The initial dose of oliceridine was 15 ug/kg, with sequential 1.5 ug/kg adjustments based on response. ED50 and ED95 were calculated using the modified Dixon's up-and-down method and Probit regression analysis. Vital signs, adverse events, anesthesia induction time, recovery time, and satisfaction scores (patients, anesthesiologists, and endoscopists) were recorded. Results: When combined with 0.3 mg/kg remimazolam, the ED50 and ED95 of oliceridine for suppressing insertion responses were 12.717 ug/kg and 18.818 ug/kg, respectively. The time from drug administration to successful scope insertion was 2 (2, 3) minutes, and the recovery-to-discharge time was 21 (16.5, 22.5) minutes. Vital signs remained stable throughout the procedure, with no hypoxemia, hypotension, or arrhythmias. No anesthesia-related adverse events (eg, nausea, vomiting and dizziness) occurred. Satisfaction scores were high: 10 (10, 10) for patients, 10 (9, 10) for anesthesiologists, and 9 (8, 10) for endoscopists. Conclusion: Oliceridine combined with 0.3 mg/kg remimazolam effectively suppresses gastroscope insertion response at ED50 and ED95 doses of 12.717 ug/kg and 18.818 ug/kg, respectively. This optimized regimen provides hemodynamic stability, rapid recovery and high procedural satisfaction, with no observed adverse events. These findings support its clinical utility as a safe and efficient anesthetic protocol for painless gastroscopy. Trial Registration: Chinese Clinical Trial Registry (ChiCTR2400093416).