Influence of dexamethasone on the incidence of postoperative nausea and vomiting in breast cancer patients with neoadjuvant chemotherapy

Objective: To evaluate the influence of dexamethasone on the incidence of postoperative nausea and vomiting( PONV) in patients undergoing modified radical mastectomy with neoadjuvant chemotherapy. Methods: In a prospective trial,280 female( 18- 60 years) breast cancer patients undergoing modified radical mastectomy with neoadjuvent chemotherapy were randomized to two groups: one with dexamethasone( Group D) and one without dexamethasone( Group C,n = 140). In each group,anesthesia was maintained with volatile anesthesia or total intravenous anesthesia( TIVA) : TIVA( propofol) without dexamethasone( Subgroup CP); volatile anesthesia( sevoflurane) without dexamethasone( Subgroup CS); TIVA with 10 mg dexamethasone intravenously before anesthetic induction( Subgroup DP); volatile anesthesia with 10 mg dexamethasone intravenously before anesthetic induction( Subgroup DS). A standard general anesthetic technique was used. All the patients received 8 mg of ondansetron intravenously 30 minutes before the end of surgical procedures. The incidence of PONV during the 24-hour postoperative period was recorded. A Logistic regression analysis was conducted to examine relevant factors for PONV. The tested factors were: age,body mass index( BMI),duration of surgery,postoperative pain,history of motion sickness / PONV,with or without dexamethasone and anesthetic regimen.Results: There was a significant lower incidence of PONV in the patients who received dexamethasone than in those who received placebo during the 24-hour postoperative period( 11. 4% vs. 20. 7%,P = 0. 034). In the early postoperative period( 0- 2 h) dexamethasone reduced the incidence of PONV( 1. 4% vs. 6. 4%,P = 0. 031),but in the late postoperative period( 2- 24 h) the difference of the incidence was insignificantly( 10. 7% vs. 17. 9%,P = 0. 088). No differences were found between TIVA and volatile anesthesia in the 24-hour postoperative period. Dexamethasone was effective to prevent PONV( OR = 0. 447,P = 0. 030),and history of PONV or motion sickness was the risk factor of PONV( OR = 15. 730,P 0. 001). Conclusion: Dexamethasone prevents PONV effectively in patients undergoing modified radical mastectomy with neoadjuvant chemotherapy,and TIVA cannot decrease the incidence of PONV in the 24-hour postoperative period in those patients.