A Clinical Study of SHR8554 Injection for the Treatment of Pain After Abdominal Surgery.

A Phase III, Randomized, Double-Blind, Placebo- and Active-controlled Study of SHR8554 Injection for the Treatment of Pain After Abdominal Surgery.

The primary objective is to evaluate the analgesic efficacy of IV SHR8554 compared with placebo and morphine in patients with acute postoperative pain following abdominal surgery

Inclusion Criteria:

1. Able and willing to provide a written informed consent
2. Subjects requiring elective general anesthesia abdominal surgery
3. Conform to the ASA Physical Status Classification

Exclusion Criteria:

1. Subjects with a history of difficult airway
2. Subjects with a history of reflux esophagitis
3. Subjects with a history of mental illness
4. Subjects with poor blood pressure control
5. Transcutaneous oxygen saturation (SpO2) <90%
6. Random blood glucose ≥11.1mmol/L
7. Subjects with abnormal liver function
8. allergies to opioids and other medications that may be used during the trial
9. Pregnant or nursing women