A Study of Suitable Oliceridine-Ciprofol Dose Combinations for Sedation During Gastroscopy in Older Adults

INTERVENTION: D04 Middle‐Low Group:Oxalidine 1.0 mg; Cyclophenol 0.2 mg/kg;D09 High‐High Group:Oxalidine 1.5 mg; Cyclophenol 0.4 mg/kg;D03 Low‐High Group:Oxalidine 0.5 mg; Cyclophenol 0.4 mg/kg;D02 Low‐Middle Group:Oxalidine 0.5 mg; Cyclophenol 0.3 mg/kg;D01 Low‐Low Group:Oxalidine 0.5 mg; Cyclophenol 0.2 mg/kg;D06 Middle‐High Group:Oxalidine 1.0 mg; Cyclophenol 0.4 mg/kg;D08 High‐Middle Group:Oxalidine 1.5 mg; Cyclophenol 0.3 mg/kg;D07 High‐Low Group:Oxalidine 1.5 mg; Cyclophenol 0.2 mg/kg;D05 Center‐dose Concurrent Reference Group:Oxalidine 1.0 mg; Cyclophenol 0.3 mg/kg; CONDITION: Inadequate sedation and sedation/analgesia‐related respiratory‐depression risk in older adults undergoing elective diagnostic painless gastroscopy. PRIMARY OUTCOME: Clinically significant respiratory depression;Initial‐dose sedation success; SECONDARY OUTCOME: Time to MOAA/S <= 2;Hemodynamic safety variables;Rescue ciprofol use;Adverse and serious adverse events;Movement score;Maximum EtCO2;Minimum SpO2;Recovery and discharge times;Delayed events at 24 hours;Highest airway‐intervention level;Duration of respiratory events;Completion of gastroscopy; INCLUSION CRITERIA: 1. Aged 65–75 years, scheduled for elective diagnostic painless gastroscopy, with an expected examination duration of no more than 20 minutes; 2. ASA physical status I–III; body weight 50–90 kg, BMI 18.5–30.0 kg/m^2, Clinical Frailty Scale (CFS) <=4; 3. SpO2 >=95% while awake and at rest in room air (the body weight range is used to ensure that the exposure to 1.5 mg oliceridine does not exceed the pre‐specified upper limit of 30 µg/kg); 4. Able to understand the study, make an independent decision to participate, and provide written informed consent; 5. Judged by the investigator to be suitable to undergo the procedure under conditions with continuous pulse oximetry, non‐invasive blood pressure monitoring, electrocardiography, end‐tidal carbon dioxide monitoring, and resuscitation facilities available.