Associations with early vomiting when using intranasal fentanyl and nitrous oxide for procedural sedation in children: A secondary analysis of a randomised controlled trial

Comprehensive Summary

This secondary analysis of a randomized controlled trial examined predictors of early vomiting in children receiving intranasal fentanyl with nitrous oxide. Four hundred thirty-six children aged 3–17 years undergoing procedures including fracture reduction were enrolled. Participants were randomized to receive oral ondansetron or placebo prior to sedation with intranasal fentanyl and 70% nitrous oxide. Overall, 14% of children vomited within one hour of nitrous oxide administration, and 26% within 24 hours. Multivariable analysis demonstrated that higher total fentanyl doses were significantly associated with increased risk of early vomiting. Age, sex, weight, fasting status, procedure type, and timing of fentanyl administration were not associated with vomiting risk. Ondansetron prophylaxis was not associated with a statistically significant reduction in vomiting. Most vomiting episodes were self-limited, though they caused patient discomfort and occasionally disrupted care. Vomiting was a common adverse effect, with fentanyl dose emerging as the sole significant predictor.

Outcomes and Implications

These findings indicate that vomiting occurs in approximately one in seven children receiving intranasal fentanyl and nitrous oxide for procedural sedation, with an additional one in eight experiencing vomiting after discharge. The authors note that higher fentanyl doses increase vomiting risk, suggesting clinicians should counsel patients and families accordingly when using this regimen. The authors further highlight the potential value of investigating non-opioid analgesic adjuncts and comparing nitrous oxide concentrations (50% vs. 70%) in future studies.