A double blind comparison of droperidol and ondansetron for prevention of emesis in children undergoing orthopaedic surgery

Emesis is common in the postoperative period following epidural opioid and general anaesthesia. Eighty patients ages two to 14 years scheduled for major orthopaedic surgery were enrolled in a randomized, double-blind study to compare the prophylactic effects of ondansetron, droperidol and a placebo for the prevention of postoperative emesis. Each child was assigned at random to one of the four treatment groups: ondansetron 100 mu g.kg(-1), ondansetron 50 mu g.kg(-1), droperidol 60 mu g.kg(-1) and saline control. Drugs were administered intravenously after the induction of anaesthesia. Anaesthesia was supplemented with epidural fentanyl, given as an infusion of 1 mu g.kg(-1) and continued for postoperative pain control. The incidence of vomiting in the immediate postoperative period was 25% with ondansetron (100 mu g.kg(-1)), 40% with ondansetron (50 mu g.kg(-1)) and droperidol and 70% with the control group. in the next 48 h the incidence of emesis increased to 30% for ondansetron (100 mu g.kg(-1)), 55% with ondansetron (50 mu g.kg(-1)), 65% with droperidol and 85% for the control group. Those patients who had multiple emesis necessitating a second dose of the same drug treatment showed no difference in the incidence of emesis relative to the control group. Ondansetron (50 mu g.kg(-1)) and droperidol groups had lower incidence of PONV compared to the control group. The ondansetron (100 mu g.kg(-1)) group had a significant decrease in the incidence of emesis. We conclude that the prophylactic administration of ondansetron (100 mu g.kg(-1)) is more effective than droperidol and ondansetron (50 mu g.kg(-1)) and superior to saline (P<0.02) for the prevention of emesis before epidural opioid and general anaesthesia.