The Use of Dexamethasone for Preventing Postoperative Nausea and Vomiting in Females Undergoing Thyroidectomy: A Dose-Ranging Study

We sought to determine the minimum effective dose of dexamethasone in preventing postoperative nausea and vomiting in women undergoing thyroidectomy. Two hundred twenty-five women (n = 45 in each of five groups) undergoing thyroidectomy under general anesthesia were enrolled in this randomized, double-blinded, placebo-controlled study. Immediately after the induction of anesthesia, patients received IV dexamethasone at doses of 10 mg (D10), 5 mg (D5), 2.5 mg (D2.5), 1.25 mg (D1.25), or saline (S). We found that Groups D10 and D5 were significantly different from Group S in the total incidences of nausea and vomiting, more than four vomiting episodes, the proportions of patients requiring rescue antiemetics, and the incidences of complete responses. The differences between Groups D10 and D5 were not significant. Dexamethasone 2.5 mg reduced the total incidence of nausea and vomiting. Dexamethasone 1.25 mg was not effective. Dexamethasone 5 mg IV is the minimum effective dose in preventing postoperative nausea and vomiting in women undergoing thyroidectomy. Implications We evaluated four doses of IV dexamethasone in preventing postoperative nausea and vomiting in women undergoing thyroidectomy. We found that dexamethasone 5 mg was as effective as dexamethasone 10 mg, and was more effective than saline control. Dexamethasone 5 mg is suggested to be the minimum effective dose for this purpose.