Effect of Circadian Rhythm on the Sedative Efficacy and Recovery Quality of Ciprofol General Anesthesia: A Multi-Center Observational Study

The goal of this multi-center observational study is to learn about the effect of circadian rhythm (morning vs. afternoon surgery) on the sedative efficacy, hemodynamic stability (especially induction-associated hypotension), and recovery quality of ciprofol general anesthesia in adult patients undergoing elective non-cardiac and non-cranial surgery, comparing target-controlled infusion (TCI) and non-TCI administration modes. The main question it aims to answer is: Does circadian rhythm (time of surgery: morning vs. afternoon) affect the sedative efficacy, incidence of induction-associated hypotension, and recovery quality of ciprofol general anesthesia? Eligible patients aged 18-65 years with ASA physical status I-II and BMI 18-30 kg/m² undergoing elective general anesthesia for non-cardiac and non-cranial surgery (duration 1-2 hours) will be grouped by anesthesia start time (morning: 08:00-11:00; afternoon: 14:00-17:00) and receive ciprofol induction and maintenance via TCI or non-TCI infusion. Perioperative data including hemodynamic changes, ciprofol dosage, recovery time, and adverse events will be recorded and analyzed.

Inclusion Criteria: 1. Aged 18-65 years, with ASA physical status I-II. 2. Body Mass Index (BMI) between 18-30 kg/m². 3. Scheduled for elective non-cardiac and non-intracranial surgery under general anesthesia, with an expected operative duration of 1-2 hours. 4. Morning group: surgery start time between 08:00 and 11:00, with completion no later than 13:00; Afternoon group: surgery start time between 14:00 and 17:00, with completion no later than 19:00. 5. Willing to participate and having provided signed informed consent. Exclusion Criteria: 1. Severe hepatic or renal insufficiency (Child-Pugh Class C or eGFR \< 30 ml/min/1.73m²). 2. Severe cardiovascular, respiratory, or neurological diseases. 3. Long-term use of sedative-hypnotics, anxiolytics, antidepressants, or glucocorticoids. 4. Known allergy to ciprofol, propofol, or their excipients. 5. Recent (within 3 months) history of shift work, transmeridian travel, or other conditions that may cause circadian rhythm disruption. 6. Pregnant or lactating women. 7. Any other condition deemed by the investigator as unsuitable for participation in this study.