Pyridoxine Prevents Postoperative Nausea and Vomiting in Gynecological Laparoscopic Surgery: A Double-blind Randomized Controlled Trial.

BACKGROUND Postoperative nausea and vomiting (PONV) are common complications after gynecological laparoscopic surgery. Pyridoxine has been recommended as a first-line drug to prevent and treat nausea and vomiting during pregnancy; however, its efficacy in preventing PONV remains unclear. METHODS Patients of 18 to 65 years old, who received elective gynecological laparoscopic surgery under general anesthesia, were randomized into either the pyridoxine or control group. The pyridoxine group received 0.2g vitamin B6 before anesthesia induction, and the control group received normal saline intravenously. Both groups received a similar regimen of combined intravenous and inhalation general anesthesia. All patients received dexamethasone(intravenous) after anesthesia induction and ondansetron(intravenous) before surgery completion. PONV occurrence was recorded according to the patients' self-reported data. Other clinical data were collected from hospital system, and concentrations of blood interleukin-6 and substance P were measured by ELISA. RESULTS A total of 442 patients were screened and 240 patients were equally randomized to the pyridoxine or control group. The incidence of PONV was statistically significant lower in the pyridoxine group than in the control group (16.7% [20/120] vs. 35.8% [43/120]; relative risk (RR) = 0.47 [95% CI: 0.29, 0.74]; absolute risk reduction (ARR) = 0.20 [95% CI: 0.08, 0.30]; P = 0.001), and pyridoxine decreased the incidence of postoperative nausea (12.5% [15/120] vs. 35% [42/120]; RR = 0.36 [95% CI: 0.21, 0.61]; ARR = 0.23 [95% CI: 0.12, 0.33]; P < 0.001). There were no statistical differences in postoperative vomiting, time to the first PONV occurrence, pain, serum interleukin-6 and substance P, and white blood cell and neutrophil counts. CONCLUSION In this single center randomized trial, pyridoxine plus dexamethasone and ondansetron reduced the incidence of PONV in patients undergoing elective gynecological laparoscopic surgery under general anesthesia. These findings need to be validated in multicenter studies in diverse populations to ensure generalizability.