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

Abstract

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.

Keywords: anaesthesia; emergency department; paediatric emergency medicine; paediatric injury.