Effect of low-dose propofol combined with dexamethasone on the prevention of postoperative nausea and vomiting in gynaecological day surgery under remimazolam-based general anesthesia

To observe the effect of low-dose propofol combined with dexamethasone on the prevention of postoperative nausea and vomiting (PONV) in gynaecological day surgery under remimazolam-based general anesthesia.A total of 120 patients, aged from 18 to 65 years old, American Society of Anesthesiologists grade I or II, were scheduled to undergo hysteroscopy under total intravenous anesthesia. The patients were divided into 3 groups (n = 40 each): dexamethasone plus saline group (DC group), dexamethasone plus droperidol group (DD group) and dexamethasone plus propofol group (DP group). Dexamethasone 5 mg and flurbiprofen axetil 50 mg were given intravenously before induction of general anesthesia. Anesthesia induction: remimazolam 6 mg/kg/hours was continuously pumped until sleep and slow intravenous injection of alfentanil 20 ug/kg and mivacurium chloride 0.2 mg/kg was given. Anesthesia maintenance: remimazolam 1 mg/kg/hour and alfentanil 40 ug/kg/hours were continuously pumped. After the start of surgery, DC group was given 2 mL saline, DD group was given droperidol 1 mg, and DP group was given propofol 20 mg. Primary outcome: incidence of PONV in the postanesthesia care unit (PACU). Secondary outcome: incidence of PONV in patients within 24 hours after surgery, as well as general patient data, duration of anesthesia, the recovery time of patients, dose of remimazolam and alfentanil, etc.In PACU, patients of group DD and DP showed less PONV than those in group DC (P < .05). Within 24 hours after operation, there was no significant difference in the incidence of PONV among the 3 groups (P > .05), but the incidence of vomiting in DD group and DP group was significantly lower than that in DC group (P < .05). There was no significant difference in general data, anesthesia time, the recovery time of patients and dosage of remimazolam and alfentanil among the 3 groups (P > .05).The effect of low-dose propofol combined with dexamethasone to prevent PONV under remimazolam-based general anesthesia was similar to that of droperidol combined with dexamethasone, both of which significantly reduced the incidence of PONV in the PACU compared to dexamethasone alone. However, low-dose propofol combined with dexamethasone had little effect on the incidence of PONV within 24 hours compared to dexamethasone alone and only reduced the incidence of postoperative vomiting in patients.