Effect of ondansetron on the incidence of vomiting associated with ketamine sedation in children: a double-blind, randomized, placebo-controlled trial

Ann Emerg Med. 2008 Jul;52(1):30-4. doi: 10.1016/j.annemergmed.2008.01.326. Epub 2008 Mar 19.


Study objective: We investigate the effect of ondansetron on the incidence of vomiting in children who receive intravenous (IV) ketamine for procedural sedation and analgesia in the emergency department (ED).

Methods: In this double-blind, randomized, placebo-controlled trial in a children's hospital ED, patients receiving IV ketamine (1 mg/kg) for ED procedures were randomized to receive either IV ondansetron (0.15 mg/kg; maximum 4 mg) or identical placebo. We recorded whether vomiting occurred in the ED postsedation or up to 12 hours after discharge with telephone follow-up and compared ED length of stay and parental satisfaction.

Results: One hundred twenty-seven children were randomized to placebo and 128 to ondansetron. The groups were similar in age, sex, and fasting duration. ED vomiting was less common with ondansetron: 6 of 128 (4.7%) versus 16 of 127 (12.6%), P=.02, difference 7.9% (95% confidence interval 1.1% to 14.7%), number needed to treat 13. Follow-up was successful in 82.7%, with vomiting in the ED or after discharge less frequent with ondansetron: 10 of 128 (7.8%) versus 24 of 127 (18.9%), P=.01, difference 11.1% (95% confidence interval 2.7% to 19.5%), number needed to treat 9. ED length of stay and parental satisfaction were similar between groups.

Conclusion: IV ondansetron significantly reduces the incidence of vomiting associated with IV ketamine procedural sedation in children.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Anesthetics, Dissociative / adverse effects*
  • Antiemetics / therapeutic use*
  • Chi-Square Distribution
  • Child
  • Child, Preschool
  • Double-Blind Method
  • Emergency Service, Hospital
  • Female
  • Humans
  • Incidence
  • Infant
  • Ketamine / adverse effects*
  • Male
  • Ondansetron / therapeutic use*
  • Treatment Outcome
  • Vomiting / drug therapy*
  • Vomiting / epidemiology
  • Vomiting / etiology


  • Anesthetics, Dissociative
  • Antiemetics
  • Ondansetron
  • Ketamine