Safety and efficacy of a nitrous oxide procedural sedation programme in a paediatric emergency department: a decade of outcomes.

Background: Nitrous oxide (NO) has multiple benefits in paediatric procedural sedation (PPS), but use is restricted by its limited analgesic properties. Analgesic potency could be increased by combining NO and intranasal fentanyl (INF). We assessed safety and efficacy data from 10 years (2011-2021) of our NO PPS programme.

Methods: Prospectively collected data from a sedation registry at a paediatric emergency department (PED) were reviewed. Total procedures performed with NO 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 NO concentrations, NO 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 NO procedural sedations were performed, 358 (43.1%) involved a combination INF and NO. 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/NO 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 NO alone. No serious adverse events (SAEs) were reported (desaturation, apnoea, aspiration, bradycardia or hypotension) regardless of NO 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 NO 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: NO can provide effective PED PPS. No SAEs were recorded. INF may be an effective PPS adjunct but remains limited by increased rates of vomiting.