The use of inhaled nitrous oxide for analgesia in adult ED patients: a pilot study

Am J Emerg Med. 2016 Feb;34(2):269-73. doi: 10.1016/j.ajem.2015.10.038. Epub 2015 Oct 24.


Background: Oligoanalgesia challenges emergency department (ED) health care providers and remains an area of patient dissatisfaction. Nitrous oxide (NO) is a safe, quick-acting, and well-tolerated sedative agent with analgesic and anxiolytic properties that make it ideal for ED use.

Objectives: We seek to test the effectiveness of a self-administered and self-contained NO device as an analgesic agent in the ED and assess patient and staff satisfaction with this method.

Methods: We enrolled 85 patients 18 years and older in a prospective observational study of patients presenting to the ED with moderate to severe pain (≥30 mm on a 100-mm visual analog scale). Subjects received a mixture of 50% NO via a self-administered portable delivery device. Primary outcome was the reduction in baseline pain scores at 20, 40, and 60 minutes. Secondary outcomes were patient, nurse, and physician satisfaction as reported on a brief satisfaction questionnaire.

Results: There was a significant reduction in mean pain scores from baseline to 20 minutes that was sustained through the 60-minute period. Most subjects (93%; 95% confidence interval [CI], 85%-97%) and nurses (97%; 95% CI, 90%-99%) reported that the NO delivery system was easy to use and were satisfied with the level of pain relief and would use NO in the future (82%; 95% CI, 73%-89%). Physicians and nurses were also satisfied with the analgesic effects of NO (82%; 95% CI, 73%-89%).

Conclusions: The portable NO device is an effective analgesia adjunct for ED patients presenting with painful conditions, and patients, ED nurses, and emergency physicians are satisfied with its use. Nitrous oxide coupled with a nurse-driven analgesia protocol may provide a novel solution for improvement in ED analgesia rates and overall patient satisfaction with ED pain management.

Publication types

  • Observational Study

MeSH terms

  • Administration, Inhalation
  • Adult
  • Anesthetics, Inhalation / adverse effects
  • Anesthetics, Inhalation / therapeutic use*
  • Emergency Service, Hospital
  • Female
  • Humans
  • Male
  • Nitrous Oxide / adverse effects
  • Nitrous Oxide / therapeutic use*
  • Pain Management / methods*
  • Pain Measurement
  • Patient Satisfaction
  • Pilot Projects
  • Prospective Studies
  • Surveys and Questionnaires
  • Treatment Outcome


  • Anesthetics, Inhalation
  • Nitrous Oxide