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Safety and efficacy of a nitrous oxide procedural sedation programme in a paediatric emergency department: a decade of outcomes
  1. Sean Croughan1,2,
  2. Michael Barrett1,3,
  3. Ronan O'Sullivan4,
  4. Aidan Beegan5,6,
  5. Carol Blackburn1,3
  1. 1 Emergency Medicine, Children's Health Ireland at Crumlin, Dublin, Ireland
  2. 2 Department of Intensive Care, Cork University Hospital, Cork, Ireland
  3. 3 Department of Women's and Children's Health, University College Dublin, Dublin, Ireland
  4. 4 Emergency Medicine, Bon Secours Health System Ltd, Cork, Ireland
  5. 5 Clinical Research Centre, Children's Health Ireland, Dublin, Ireland
  6. 6 Data Science Centre, Royal College of Surgeons in Ireland, Dublin, Ireland
  1. Correspondence to Dr Carol Blackburn, Emergency Medicine, Children's Health Ireland, Dublin 12, Ireland; carol.blackburn{at}


Background Nitrous oxide (N2O) has multiple benefits in paediatric procedural sedation (PPS), but use is restricted by its limited analgesic properties. Analgesic potency could be increased by combining N2O and intranasal fentanyl (INF). We assessed safety and efficacy data from 10 years (2011–2021) of our N2O PPS programme.

Methods Prospectively collected data from a sedation registry at a paediatric emergency department (PED) were reviewed. Total procedures performed with N2O alone or with INF, success rate, sedation depth and adverse events were determined. Contributing factors for these outcomes were assessed via regression analysis and compared between different N2O concentrations, N2O in combination with INF, and for physician versus nurse administered sedation. A post hoc analysis on factors associated with vomiting was also performed.

Results 831 N2O procedural sedations were performed, 358 (43.1%) involved a combination INF and N2O. Nurses managed sedation in 728 (87.6%) cases. Median sedation depth on the University of Michigan Sedation Scale was 1 (IQR 1–2). Sedation was successful in 809 (97.4%) cases. Combination INF/N2O demonstrated higher median sedation scores (2 vs 1, p<0.001) and increased vomiting (RR 1.8, 95% CI 1.3 to 2.5), with no difference in sedation success compared with N2O alone. No serious adverse events (SAEs) were reported (desaturation, apnoea, aspiration, bradycardia or hypotension) regardless of N2O concentration or use of INF. 137 (16.5%) minor adverse events occurred. Vomiting occurred in 113 (13.6%) cases and was associated with higher concentrations of N2O and INF use, but not associated with fasting status. There were no differences in adverse events (RR 0.98, 95% CI 0.97 to 1.04) or success rates (RR 0.93, 95% CI 0.56 to 1.7) between physician provided and nurse provided sedation.

Conclusion N2O can provide effective PED PPS. No SAEs were recorded. INF may be an effective PPS adjunct but remains limited by increased rates of vomiting.

  • anaesthesia
  • emergency department
  • paediatric emergency medicine
  • paediatric injury

Data availability statement

Data are available upon reasonable request. Any data pertaining to the research may be obtained in a de-identified format from the corresponding author, provided a reasonable request is made within an acceptable timeframe.

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Data availability statement

Data are available upon reasonable request. Any data pertaining to the research may be obtained in a de-identified format from the corresponding author, provided a reasonable request is made within an acceptable timeframe.

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  • Handling editor Shammi L Ramlakhan

  • Twitter @DrMBarrett

  • Contributors SC: Conceptualisation, methodology, validation, formal analysis, data curation, writing—original draft, writing—review and editing, guarantor. MB: Conceptualisation, methodology, validation, writing—review and editing, supervision, guarantor. RO: Conceptualisation, methodology, writing—review and editing, guarantor. AB: Formal analysis; CB: Conceptualisation, methodology, validation, writing—review and editing, supervision, CB; guarantor.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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