Perioperative Dexamethasone Split Between Two Doses Further Reduced Early Postoperative Nausea and Vomiting Than Single-Dose Dexamethasone: A Randomized Blinded Placebo-Controlled Trial.

Background: We investigated whether two doses of dexamethasone are more effective than a single dose in reducing early postoperative nausea and vomiting (PONV) during total knee arthroplasty (TKA).

Methods: A total of 150 patients between June 2021 and June 2022 were randomized into 3 groups: two doses of normal saline (group A), a single dose of 10 mg dexamethasone before surgery and normal saline after surgery (group B), and two doses of 5 mg dexamethasone during the perioperative period (group C). Primary outcomes were incidences and severity of PONV within 24 hours after surgery, the number and consumption of patients requiring morphine and metoclopramine, and visual analog scale scores for nausea and vomiting at 2, 4, 6, and 24 hours after surgery. Blood glucose levels on days 1, 2, and 3 after operation and incidences of surgical site infection (SSI) as well as gastrointestinal bleeding (GIB) within 45 days after operation were compared.

Results: Within 24 hours after operation, the number and consumption of patients requiring morphine and metoclopramide in groups B and C were significantly lower than those in group A. Incidences and severity of PONV in groups B and C were significantly lower than those in group A. And these differences between groups B and C were significant. At 2, 4, 6, and 24 hours after operation, there were significant differences in visual analog scale scores of PONV between groups A and B, A and C, as well as B and C. On postoperative days 1, 2, and 3, there were no significant differences in blood glucose levels among the groups, and there were no incidences of SSI or GIB in any group within 45 days after operation.

Conclusion: Dexamethasone significantly reduces PONV within 24 hours after TKA, does not result in significant changes in postoperative blood glucose levels, and does not increase the risk of SSI or GIB, particularly on group C.

Registration number: ChiCTR2400088512.

Registration center: Chinese Clinical Trial Registry (ChiCTR). WEBSITE: www.chictr.org.cn.