Pediatrics/original research
Effect of Ondansetron on the Incidence of Vomiting Associated With Ketamine Sedation in Children: A Double-Blind, Randomized, Placebo-Controlled Trial

Presented at the Pediatric Academic Societies meeting, May 2006, San Francisco CA.
https://doi.org/10.1016/j.annemergmed.2008.01.326Get rights and content

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.

Introduction

Ketamine is widely used for emergency department (ED) procedural sedation and analgesia in children.1, 2 Important adverse events associated with ketamine include hypoxia, laryngospasm, apnea, vomiting, and emergency reactions.2, 3, 4 The reported frequency of vomiting ranges from 3.8% to 18.7%.1, 2, 5, 6, 7, 8, 9, 10, 11 Ondansetron has been widely used in a variety of settings to reduce vomiting associated with viral illnesses, chemotherapy, and anesthesia.12, 13, 14, 15, 16 This antiemetic is increasingly used in the ED, including for the treatment of ketamine-associated vomiting.

Although ondansetron is often used to treat ketamine-associated vomiting, its efficacy for prophylaxis is unknown. Vomiting may increase ED length of stay and decrease patient satisfaction. Although clinically apparent pulmonary aspiration has never been reported during ED procedural sedation and analgesia in children, vomiting during such sedation could increase its risk.17, 18

We wished to determine whether vomiting associated with intravenous (IV) ketamine may be reduced or eliminated by the addition of prophylactic ondansetron.

Section snippets

Study Design

A convenience sample of children was enrolled in a randomized, double-blind, placebo-controlled trial of ondansetron with ED ketamine sedation. Written, informed consent was obtained from all parents or guardians, as well as assent from all children 7 years of age or older, before enrollment into the study. The study was approved by the Colorado Multiple Institutional Review Board.

Setting

This study was conducted at a university-affiliated, urban children's hospital ED, which is a regional pediatric

Results

This study was conducted from January 2003 to August 2005. Eligible and enrolled patients during the study period are shown on the patient flow diagram (Figure). Two hundred sixty-eight patients were randomized; 850 patients met criteria but were not enrolled because of parent or patient refusal or, more commonly, nonavailability of a research assistant to enroll patients during busy ED patient volume times. Characteristics of the enrolled patients are listed (Table 1).

Patients who received

Limitations

This study has several important limitations. Because of our inability to enroll consecutive patients in a busy ED, this work represents a convenience sample of patients. Failure to enroll all eligible patients makes this study susceptible to selection bias. As a result of our sample size, the 95% CI for the number needed to treat is relatively wide, suggesting the true effect may be larger or smaller. In addition, although telephone follow-up was obtained for almost 83% of patients, those not

Discussion

Previous studies of IV ketamine in the ED have reported a wide range of vomiting (3.8% to 18.7%), with research from our institution reporting 9.3% t 18.7%.2, 11, 26 In addition, some children (3.6% o 9.1%) who do not vomit in the ED do vomit after discharge.2, 11 Because of these relatively high rates of vomiting, we sought to determine whether the addition of the antiemetic drug ondansetron could decrease or prevent vomiting associated with ketamine.

Several factors may influence vomiting

References (28)

  • D. Agrawal et al.

    Preprocedural fasting state and adverse events in children undergoing procedural sedation and analgesia in a pediatric emergency department

    Ann Emerg Med

    (2003)
  • M.G. Roback et al.

    Adverse events associated with procedural sedation and analgesia in a pediatric emergency department: a comparison of common parenteral drugs

    Acad Emerg Med

    (2005)
  • R.D. Pitetti et al.

    Safe and efficacious use of procedural sedation and analgesia by nonanesthesiologists in a pediatric emergency department

    Arch Pediatr Adolesc Med

    (2003)
  • S.M. Green et al.

    Intravenous ketamine for pediatric sedation in the emergency department: safety profile with 156 cases

    Acad Emerg Med

    (1998)
  • Cited by (0)

    Supervising editor: Steven M. Green, MD

    Author contributions: WTL, JEW, and MGR conceived of the study and designed the trial. WTL and JEW supervised data collection. LB provided statistical analyses of the data. MR drafted the article, and all authors contributed to its revision. JEW takes responsibility for the paper as a whole.

    Funding and support: By Annals policy, all authors are required to disclose any and all commercial, financial, and other relationships in any way related to the subject of this article, that may create any potential conflict of interest. See the Manuscript Submission Agreement in this issue for examples of specific conflicts covered by this statement. Financial support was from the Children's Hospital Research Institute, Denver, CO.

    Publication dates: Available online March 19, 2008.

    Reprints not available from the authors.

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