Prevention of vomiting after strabismus surgery in children: dexamethasone alone versus dexamethasone plus low-dose ondansetron

BACKGROUND: Postoperative vomiting is a common complication after strabismus surgery. The combination of dexamethasone and ondansetron decreases vomiting after strabismus surgery, while dexamethasone alone decreases vomiting after tonsillectomy in children. We compared the effect of dexamethasone alone to ondansetron plus dexamethasone on postoperative vomiting among children undergoing strabismus surgery. METHODS: Healthy children, aged 2-14 years, who were undergoing strabismus surgery were entered into this randomized, blocked and stratified study. Patients were administered 0.5 mg.kg(-1) midazolam p.o., 20-30 min preoperatively when indicated. The patients had an intravenous induction with 2.5-3.5 mg.kg(-1) propofol or an inhalation induction of anaesthesia with halothane and N2O. All patients were given 20 microg.kg(-1) atropine i.v. Study drugs were administered in a double-blind fashion. Both groups received 150 microg.kg(-1) dexamethasone i.v. Group D patients received placebo and group OD received 50 microg.kg(-1) of ondansetron i.v. Anaesthesia was maintained with halothane and N2O. Postoperative fluid, vomiting and pain management were standardized. Patients were followed for 24 h. We studied 193 patients with 111 patients in the OD group. Demographic data were similar. RESULTS: The overall incidence of vomiting was 23%; in group D and 5%; in group OD (P < 0.001). Each episode of vomiting increased the in-hospital length of stay by 29 min (P < 0.001). CONCLUSIONS: There was a remarkably low incidence of postoperative vomiting of 5%; with the combination of dexamethasone plus a low-dose of ondansetron which more effectively decreased vomiting after strabismus surgery in children when compared with dexamethasone alone.