Effect of Ondansetron on the Incidence of Ketamine Associated Vomiting in Procedural Sedation and Analgesia in Children: A Double-Blind, Randomized, Placebo-Controlled Trial

Background Vomiting is a common side effect of ketamine in children's sedation and there is still controversy about the use of an anti-emetic drug along with ketamine to reduce this complication. The aim of this study was to evaluate the effectiveness of ondansetron in controlling vomiting induced by intramuscular (IM), and intravenous (IV) ketamine for procedural sedation and analgesia in children in the emergency department (ED). Materials and Methods In a double-blind, randomized, placebo-controlled clinical trial, children aged 1 to 10 years who received ketamine for ED procedures were randomized into four groups receive IV ketamine (1.5 mg/kg), and placebo, IM ketamine (5mg/kg) and placebo, IV ketamine and IV ondansetron (0.15 mg/kg), and IM ketamine and oral ondansetron. The incidence of nausea and vomiting and ED length of stay were compared as the outcome of the study. Results One hundred eighty children were enrolled and randomized to four groups; 29 patients (15.0%) had nausea and vomiting. The incidence of vomiting was 26.7% in the IV ketamine-placebo group and 8.9% in the IV ketamine/ IV ondansetron group (P = 0.02). The incidence of vomiting was 17.8% in the IM ketamine-placebo group and 11.1% in the IM ketamine/oral ondansetron group (P = 0.17). ED length of stay was similar between groups. Conclusion According to current results, children administered IV ondansetron before IV ketamine experienced a significantly reduced incidence of vomiting but did not significantly affect length of ED stay and the addition of oral ondansetron to IM ketamine dose not reduce vomiting.