HSK16149 for Perioperative Analgesia in Orthopedic Surgery

Inclusion Criteria: Male or female between the ages of 18 and 75 years (included); Elective orthopedic surgery under general anesthesia, expected operation time ≤4 hours and postoperative morphine analgesia time ≥24 hours; 18kg/m^2≤BMI≤30 kg/m^2; American Society of Anesthesiologists (ASA) grade I and II; Exclusion Criteria: Any of the following medical histories or conditions prior to screening: Long history of chronic pain; history of severe cardiovascular or respiratory disease; history of neurological or psychiatric disorders; history of acute poisoning with alcohol, hypnotics, analgesics or other drugs acting on the central nervous system; major surgery within 3 months; patients with high bleeding risk; history of renal disease treated with dialysis within 28 days before surgery; have active infection within the past 2 weeks; Use of any of the following medications or treatments: opioid analgesics for more than 10 consecutive days within 3 months prior to screening; other analgesics before randomization if the last dose was taken less than 5 half-lives of the drug (according to the label); Abnormal laboratory tests during screening: Hypertension that is not adequately controlled by antihypertensive drugs (systolic blood pressure ≥160 mmHg and/or diastolic blood pressure ≥100 mmHg), or systolic blood pressure ≤90 mmHg during screening; A history of drug abuse, and/or alcohol abuse in the 3 months prior to screening; Participated in another clinical trial and received IMP within 30 days prior to screening; Pregnant or lactating women; Unwillingness to use reliable contraceptive methods from the time of screening until 28 days after the last dose of IMP;