Investigational drugs
Ciprofol emulsion (20 mL: 200 mg in part 1, and 20 mL: 50 mg in part 2 (Liaoning Haisco Pharmaceutical Group Co., Ltd., China) and Diprivan® (20 mL: 200 mg, AstraZeneca, UK).Midazolam (Jiangsu Nhwa Pharmaceutical Co., Ltd., China), sufentanil (Yichang Humanwell Pharmaceutical Co., Ltd., China) and rocuronium bromide (Esmeron, N.V. Organon, The Netherlands) were given in combination during the induction of general anesthesia.