ED90 of Tegileridine Combined With Propofol For Painless Gastroscopy

This single-group, open-label, biased-coin up-and-down sequential dose-finding trial aims to determine the 90% effective dose (ED90) of intravenous tegileridine combined with fixed-dose propofol to eliminate body movement, cough and excessive hemodynamic fluctuations during gastroscopy insertion in adult patients stratified into young (18-64 years) and elderly (≥65 years) subgroups. All subjects receive intravenous tegileridine followed by 1-2 mg/kg propofol for sedation induction. The initial tegileridine dose is 5 μg/kg with a 1 μg/kg dose step. Dose adjustment follows biased-coin algorithm: dose increases by 1 μg/kg if positive response occurs; if negative response, there is an 11% probability to decrease dose by 1 μg/kg. The trial will be terminated when 45 successful cases are accrued in each age subgroup. Primary outcome is ED90 of tegileridine calculated via centered isotonic regression. Secondary outcomes include total propofol consumption, MOAA/S sedation score, blood pressure and heart rate changes, and incidence of perioperative adverse events within 24 hours post-procedure.

Inclusion Criteria: * Outpatients scheduled for elective painless gastroscopy * Age ≥ 18 years old * American Society of Anesthesiologists (ASA) physical status I-III * Body mass index (BMI) between 18.5 and 29.9 kg/m² Exclusion Criteria: * Resting SBP ≥ 160 mmHg, DBP ≥ 110 mmHg, or heart rate ≥ 110 beats/min on admission to endoscopy room * Continuous opioid medication use for more than 2 weeks within 6 months before the procedure * Known hypersensitivity or allergic reaction to tegileridine, propofol or any excipients of the two drugs * Diagnosed psychiatric disorders or inability to communicate and cooperate with study assessment