Effect of Goreisan, a traditional Japanese Kampo medicine, on postoperative nausea and vomiting in gynecological patients

Background: Goreisan, a traditional Japanese Kampo medicine, may prevent postoperative nausea and vomiting (PONV). The purpose of this study was to evaluate the effect of Goreisan on PONV in a high-risk population in a randomized, double-blind, placebo-controlled manner. Findings: Patients undergoing gynecological surgery were randomly allocated to the Goreisan and the control groups. General anesthesia was induced with propofol and remifentanil. After endotracheal intubation, anesthesia was maintained with sevoflurane, fentanyl, and remifentanil. Goreisan 7.5 g dissolved in water (Goreisan group) or water (control group) in a volume of 20 ml was administered through a nasogastric tube approximately 1 h before completion of surgery. The primary outcome of this study was the incidence of PONV during the first 2 h after extubation. In the interim analysis, it was apparent that Goreisan has no effect. Therefore, we discontinued recruiting patients and present results based on data from 83 patients. The incidence of PONV during the first 2 h after extubation was 45% in the Goreisan group (n = 40) and 46.5% in the control group (n = 43) (p = 0.89). There was no significant difference in PONV incidence or severity during the first 24 h post-extubation. Conclusion: Goreisan has little potency in preventing PONV in high-risk patients.