High-concentration nitrous oxide for procedural sedation in children: adverse events and depth of sedation.
OBJECTIVE
Nitrous oxide is an attractive agent for procedural sedation and analgesia in the emergency department; however, there are limited safety data for high-concentration continuous-flow nitrous oxide (50%-70%) and its use in young children. We set out to characterize the depth of sedation and incidence of adverse events associated with various concentrations of nitrous oxide used in a pediatric emergency department.


METHODS
This was a prospective observational study of nitrous oxide use for procedural sedation and analgesia in a tertiary children's hospital emergency department. Nitrous oxide concentration, adverse events, and sedation depth were recorded. Adverse events were categorized as mild or serious. Sedation depth was recorded on a sedation scale from 0 to 6.


RESULTS
A total of 762 patients who were aged 1 to 17 years received nitrous oxide during the 2-year study period. A total of 548 (72%) received nitrous oxide 70%, and 101 (13%) received nitrous oxide 50%. Moderate or deep sedation with scores of < or = 2 occurred in 3% of patients who had received nitrous oxide 70% and no patients who had received nitrous oxide 50%. Mean sedation scores were 4.4 at nitrous oxide 70% and 4.6 at nitrous oxide 50%. Sixty-three (8.3%) patients sustained 70 mild and self-resolving adverse events, most of which were vomiting (5.7%); 2 (0.2%) patients had serious adverse events. There was no significant difference in adverse events rates between nitrous oxide 70% (8.4%) and nitrous oxide 50% (9.9%). There was no significant difference in the percentage of deep sedation when children who were < or = 3 years of age (2.9%) were compared with older children (2.8%).


CONCLUSIONS
In this largest prospective emergency department series, high-concentration continuous-flow nitrous oxide (70%) was found to be a safe agent for procedural sedation and analgesia when embedded in a comprehensive sedation program. Nitrous oxide also seems safe in children aged 1 to 3 years.
Babl
Franz E
FE
Emergency Department, Royal Children's Hospital, Parkville, Vic 3055, Australia. franz.babl@rch.org.au
Oakley
Ed
E
Seaman
Cameron
C
Barnett
Peter
P
Sharwood
Lisa N
LN
D000293:Adolescent; D000758:Anesthesia / Q000379:methods; D000762:Anesthesia Recovery Period; D018685:Anesthetics, Inhalation / Q000008:administration & dosage* / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D016292:Procedural Sedation / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D004630:Emergencies; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009609:Nitrous Oxide / Q000008:administration & dosage* / Q000009:adverse effects; D011336:Probability; D011446:Prospective Studies; D012680:Sensitivity and Specificity
D018685:Anesthetics, Inhalation; D009609:Nitrous Oxide