Amisulpride Injection for the Prevention of Postoperative Nausea and Vomiting in Patients Undergoing Laparoscopic Surgery

This study is a randomized controlled clinical trial focusing on the prevention of postoperative nausea and vomiting (PONV), planned to start in May 2026 and end in April 2027. It primarily compares the efficacy and safety of amisulpride injection combined with ondansetron versus ondansetron alone in patients undergoing laparoscopic surgery. A centralized stratified block randomization method will be used. In the combination group, patients will receive a single intravenous injection of amisulpride 5 mg plus ondansetron 4 mg within 1-2 minutes after anesthesia induction, while the control group will receive ondansetron 4 mg alone. The study adopts a single-blind design, meaning that patients will not know their group assignment.

The primary objective is to evaluate the efficacy of the combination regimen in preventing PONV under different anesthesia methods. The primary endpoint is complete response (CR), defined as no vomiting or retching and no use of rescue antiemetic medication within 24 hours after surgery. Secondary endpoints include the incidence of nausea at 2, 6, 12, and 24 hours postoperatively, the proportion of patients with significant nausea (VAS >4), the incidence of vomiting, and the proportion requiring rescue medication. The study will also assess safety, as well as the effects of the combination regimen on emergence agitation, postoperative delirium, shivering, recovery of bowel function, changes in inflammatory factors, postoperative pain, and analgesic consumption.

The study population consists of patients undergoing elective laparoscopic surgery under general anesthesia. After providing informed consent, eligible participants will undergo baseline assessment, including demographic information, medical history, PONV risk factors, comorbidities, medication history, vital signs, electrocardiogram, and laboratory tests. Postoperatively, blinded assessors will collect PONV-related information during the periods of 0-2 hours, 2-6 hours, and 6-24 hours, and will also record vital signs, adverse events, and concomitant medications. The primary efficacy endpoint will be assessed within 24 hours after surgery, while safety follow-up will usually continue until postoperative day 7 or discharge.

Sample size was calculated based on the primary endpoint of CR. According to previous studies, the expected CR rate is about 57% in the combination group and 46% in the ondansetron-alone group. Using a two-independent-sample proportion difference test with a two-sided alpha of 0.05 and beta of 0.20, 323 participants are required per group. Allowing for a 10% dropout rate, 359 participants will be enrolled in each group, for a total of 718 participants.

In terms of study management, the protocol clearly defines criteria for study completion, dropout, and early withdrawal. The study will be considered complete when the last participant has finished the day-7 telephone follow-up or early withdrawal visit, and all data cleaning, review, and statistical analyses have been completed. Reasons for withdrawal include withdrawal of informed consent, loss to follow-up, death, study termination by the investigator, as well as early discontinuation due to adverse events, intolerable toxicity, or major protocol deviations.

Data management emphasizes authenticity, completeness, and traceability. Demographic data, vital signs, laboratory tests, and ECG findings may be directly entered into the case report form (CRF). Data such as nausea scores, shivering grades, agitation/delirium assessments, pain scores, bowel function recovery, and drug administration records must first be documented in source records before being transcribed into the CRF. Statistical analyses will be performed using SAS version 9.4 or above. Both an efficacy analysis set and a safety analysis set will be defined. Analyses will be stratified by anesthesia method, with methods including stratified chi-square tests, repeated-measures analysis of variance, and t-tests, while also exploring the independent effects after adjustment for confounding factors such as age, sex, duration of surgery, and anesthesia method.

Overall, the study is relatively well designed, with clear randomization procedures, a well-defined primary endpoint, a reasonable sample size calculation, and a fairly complete plan for safety evaluation, statistical analysis, and data management. It is expected to provide clinically valuable evidence on the use of amisulpride combined with ondansetron for the prevention of PONV.