Nitrous oxide has been used in general anesthesia for over 2 centuries, but its use outside of the operating room began when Tunstall introduced the nitrous oxide/oxygen mixture as an analgesic agent during labor. Since this inception, the nitrous oxide/oxygen mixture has been used readily in the fields of dentistry, gastrointestinal procedures, and children's procedural sedation. Nitrous oxide is often administrated via continuous flow or on-demand at a concentration of 50-70%.