Preprocedural fasting state and adverse events in children receiving nitrous oxide for procedural sedation and analgesia.

STUDY
OBJECTIVE: Established fasting guidelines for analgesia and sedation are difficult to follow in the emergency department (ED), and the association between preprocedural fasting and adverse events has been questioned. We characterize the fasting status of patients receiving procedural sedation and analgesia with nitrous oxide (N2O) in a pediatric ED and assess the relationship between fasting status and adverse events.
METHODS: A prospective case series was conducted in a children's hospital ED over an 8-month period. Patients receiving N2O for procedural sedation and analgesia were enrolled and followed up by telephone call. Preprocedural fasting state and adverse events, as well as N2O concentration, adjunctive drugs, and deepest level of sedation, were recorded. Adverse events were analyzed in relation to fasting status.
RESULTS: Two hundred twenty children who underwent procedural sedation and analgesia with N2O were enrolled. Fasting status was obtained in 218 patients (99.1%). Of these, 155 (71.1%; 95% confidence interval [CI], 64.5%-77.0%) did not meet fasting guidelines for solids There were no serious adverse events and no episodes of aspiration (1-sided 97.5% CI, 0%-1.7%). While in the ED, 46 minor adverse events occurred in 37 patients (16.8%; 95% CI, 12.1%-22.4%). Emesis occurred in 15 patients (7%), including 4 (6.3%; 95% CI, 1.8%-15.5%) of 63 patients who met and in 11 (7.1%; 95% CI, 3.6%-12.3%) of 155 patients who did not meet fasting guidelines for solids. There was no significant difference in median fasting duration between patients with and without emesis.
CONCLUSION: Seventy-one percent of patients undergoing ED procedural sedation and analgesia with N2O did not meet established fasting guidelines. In this series, there was no association between preprocedural fasting and emesis. There were no serious adverse events.