Dexamethasone alone vs in combination with transcutaneous electrical acupoint stimulation or tropisetron for prevention of postoperative nausea and vomiting in gynaecological patients undergoing laparoscopic surgery.

BACKGROUND Postoperative nausea and vomiting (PONV) is commonly reported after surgery and anaesthesia. We compared the effects of combinations of electrical acupoint stimulation or tropisetron with dexamethasone with the effects of dexamethasone alone, for inhibition of PONV in gynaecological patients undergoing laparoscopic surgery. METHODS We randomized 157 patients undergoing elective gynaecological laparoscopic surgery under general anaesthesia into the following three groups: acupoint stimulation+dexamethasone (Group Acu, n=53), tropisetron+dexamethasone (Group Trp, n=53), and dexamethasone alone (Group Dxm, n=51). The incidence of nausea, vomiting, and need for rescue antiemetics was recorded 2, 6, 24, and 48 h after surgery. RESULTS We found significant differences in the incidence of PONV during 24 h after surgery between the combination therapy groups and the dexamethasone-alone group (P=0.021). In the first 24 h, 28% of patients in Group Acu, 26% of patients in Group Trp, and 50% of patients in Group Dxm experienced nausea, vomiting, or both. The incidence of 24 h PONV in Group Acu was significantly lower than that in Group Dxm (P=0.048; odds ratio 0.389; 95% CI 0.170-0.891). The incidence of 24 h PONV in Group Trp was also significantly lower than that in Group Dxm (P=0.042; odds ratio 0.359; 95% CI 0.157-0.819). There was no significant difference between Group Acu and Group Trp (P=0.857). The need for antiemetic rescue medication was similar in the three groups. All groups expressed similar patient satisfaction. CONCLUSIONS Combined with dexamethasone, electrical acupoint stimulation or tropisetron is more effective in PONV prophylaxis than dexamethasone alone in gynaecological patients undergoing laparoscopic surgery. CLINICAL TRIAL REGISTRATION NCT 02096835.