Oxycodone Hydrochloride Injection in the Postoperative Pain Relieving Treatment

Inclusion criteria

• Patients of either sex aged 18 to 65 years old, with a standard body weight [standard body weight = height (cm) - 100] ±15%.
• ASA I and II.
• Scheduled on elective open upper abdominal surgery under general anesthesia (liver, gall bladder, spleen, stomach, kidney, colon surgery), of which predicted operation duration is between 2-4h.
• Hospitalized patients on non-emergency condition who have been given appropriate preoperative treatments.
• Patients who are willing to participate in the study and have signed the written informed consent.
• Negative pregnancy test result should be obtained for women of child-bearing age.

Exclusion criteria

• Long-term analgesics or psychotropic drugs (including opioids, NSAIDs, sedatives, antidepressants) taken for the chronic pain, or patients abusing alcohol.
• Body weight is less than or over ±15% of the standard body weight.
• Severe impairment of liver and renal function at preoperative stage (ALT, AST, BUN, Cr).
• Medical history of recovering from abnormal surgery anesthesia.
• Medical history of hypertension (Systolic blood pressure ≥180Hg, Diastolic blood pressure 110Hg).
• Esophagus reflux disease.
• Sedatives, anti-emetics, and anti-pruritic drugs were taken 24 hours before operation.
• Have known hypersensitivity to opioids.
• Monoamine oxidase inhibitors and antidepressant drugs were taken within 15 days.
• Patients with shock.
• Patients with COPD.
• Patients can not understand the VAS or unable to use PCA.
• Pregnant or parturient women.