A Phase IIa Study Investigating the Tolerance, Efficacy and Safety of HSK3486

Inclusion Criteria: 1. Inpatients required tracheal intubation under general anesthesia and a non-emergency non-cardiothoracic and non-extracranial elective surgery for an estimated duration of ≤ 3 h ;. 2. Males or females, aged ≥ 18 and ≤ 65 years old; 3. Body mass index (BMI) ≥ 19 and ≤ 30 kg/m2; 4. ASA grade I\~II; 5. Capable of understanding the procedure and method of this study, willing to sign an informed consent form and to complete this study in strict accordance with the study protocol. Exclusion Criteria: 1. Patients were contraindicated in general anesthesia.; 2. Patients with a known sensitivity to propofol, opioids, naloxone, eggs, soy products or a medical condition such that these agents were contraindicated 3. Patients in receipt of any investigational drug within 30 days before screening. 4. Patients in receipt of propofol, opioid , other sedative or anesthetic or analgesics within one month prior to the screening period. 5. Patients in receipt of general anesthesia surgery within two weeks prior to the screening period. 6. The patient has some history or evidence of increased risk of sedation or anesthesia, such as cardiovascular disease, respiratory disease, cerebrovascular disease, liver, kidney, blood system, or metabolic system disease prior to the screening period. 7. Abnormal laboratory results consisting of any of the following: : 1\) AST and ALT≥ 2×ULN； 2）TBIL≥ 1.5×ULN； 3）Hb≤ 90g/L; 4）ANC≤1.5×109/L; 5) PLT≤80×109/L； 6） serum creatinine≥ 1.5×ULN. 8\. Patients with a history of drug or ethanol abuse with the past 3 months. 9. Pregnant women or female patients with a positive serum or urine human chorionic gonadotropin pregnancy test at screening or baseline or lactating female patients. . 10. 10. Patients with a positive Allen 's test who collected arterial blood for PK study. 11\. Patients with respiratory management difficulties. 12. Patients with an inability to communicate well with the investigator, or deemed unsuitable according to the investigator (in each case providing a reason).