Changes of Ciprofol Dosage and Bispectral Index Required for Loss of Consciousness in Patients of Different Ages

All patients will fast for 6 hours and will abstain from drinking for 2 hours preoperatively, with no premedication. Preoxygenation will be performed with an oxygen flow rate of 6 L/min. Ciprofol will be continuously infused via a micropump at a rate of 12 mg/kg/h. During preoxygenation with a facemask, if respiratory depression occurs during ciprofol infusion, assisted ventilation via facemask will be initiated. After LOC and completion of observation indices, the anesthesiologist may administer midazolam (1-3 mg), sufentanil (0.2-0.5 μg/kg), and rocuronium (0.3-0.6 mg/kg) sequentially based on the patient's age, physical condition, and BIS values to complete anesthesia induction. If hypotension (systolic blood pressure \<90 mmHg or \<80% of baseline) or bradycardia (heart rate \<50 beats/min) occurs during induction, vasoactive agents such as ephedrine or atropine will be administered for management.