Nitrous oxide/oxygen (N2O/O2) sedation is a safe and effective means of reducing pain and anxiety for patients around the world, and its safety record spans more than 160 years. Nitrous oxide/oxygen sedation has been used in the dental setting since its analgesic properties were discovered in the 1800s. While it continues to be used as an adjuvant anesthetic agent in operating rooms, its routine use now spans several health disciplines in the ambulatory setting within the emergency medical system. Nitrous oxide/oxygen administration is expanding worldwide, which was recently evident by its inclusion into the dental school curricula at Beijing University in China.
Because of the pharmacokinetic properties of nitrous oxide, it has several advantages over other methods. Nitrous oxide provides both analgesia and anxiolysis, plus has a slight amnestic effect. It provides a rapid onset without the latent period required with oral sedation. Titration is possible with the continuous flow of nitrous oxide and oxygen equipment traditionally used in the dental setting. This delivery method provides the exact amount of drug needed for the desired outcome. Nitrous oxide is delivered as definitive amounts in incremental doses in order to observe patient response and determine appropriate sedation. This delivery is the standard of care for dental professionals because it provides the greatest patient comfort and safety. Recovery from N2O/O2 sedation is quick, as more than 99 percent of all nitrous oxide is expelled from the lungs minutes after the drug is discontinued. When nitrous oxide/oxygen administration concludes, it is standard to provide the patient with 100 percent oxygen until he/she is fully recovered. Also, nitrous oxide/oxygen sedation can be used on most patients with few side effects.
There are very few contraindications to the use of N2O/O2 sedation in an ambulatory setting. In many situations, postponement of this sedation method is recommended until specific conditions are resolved.
Relative contraindications for the administration of nitrous oxide are listed below. Medical consultation is recommended for several of the following conditions.