[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.