The Effect of Glycyrrhizin on the Occurrence of Postoperative Nausea and Vomiting

Postoperative nausea and vomiting (PONV) is one of a common complication after general anesthesia with 30-50% of incidence, increased up to 80% in high risk group. The risk factors of PONV include women population, the previous history of PONV, motion sickness in usual life, non-smoker, exposure to inhalants, perioperative opioid and laparoscopic surgery. Women population is a strong risk factor of PONV. Although perioperative management of PONV based on a guideline has been done in a lot of medical centers worldwide, the incidence of PONV is still reported relatively high. The main ingredient of Glycyrrhizin is liquorice which has been used as antispasmodics, antiemetics or treatment for gastric ulcer in oriental medicine. Utilizing these effects of liquorice, the investigators investigate whether the addition of glycyrrhzin to conventional antiemetics is effective to decrease the incidence of PONV and improvement of severity of PONV.