Nitrous Oxide-Oxygen Sedation (Laughing Gas)

By Brian J. Gray, DDS, MAGD, FICOI

The most commonly employed technique of conscious sedation in dentistry is inhalation sedation with nitrous oxide and oxygen (N₂0-0₂). It is estimated that approximately 35% of U.S. dentists use this technique.

The goal sought when N₂0-0₂ is used is to eliminate dental fears, making the patient more comfortable while the doctor is able to more effectively complete the planned treatment.

A small rubber inhaler will be placed over the patient's nose and adjusted so that the patient is comfortable. At this time, the patient will be breathing 100% oxygen. Some patients (at their first N₂0-0₂ visit) will feel that they are not getting enough "air." The patient should tell the doctor and he/she will provide them with even more oxygen to breathe.

Once the patient is comfortable breathing oxygen, the doctor gradually will introduce nitrous oxide. Over the next three to five minutes, the patient will be asked, "What are you feeling?" as the amount of nitrous oxide slowly is increased.

The signs and symptoms that most patients experience when receiving N₂0-0₂ include an initial feeling of lightheadedness, which gradually leads to an all-over feeling of warmth. Many persons mention a comfortable "vibrating" or "humming" sensation. It is common to feel one's fingertips and hands become "numb." This same sensation may develop in the mouth -- a benefit to the doctor (and patient) during dental treatment. Some patients will mention that their arms and legs feel "very light." Interestingly, other patients will say that their arms and legs feel "so heavy I can't even move them." If either of these occurs to the patient, it is perfectly normal. The individual might notice that they are perspiring a little. This is a normal effect of the nitrous oxide.

The doctor will talk with the patient throughout the procedure and the individual will be able to respond without any problem. This is a major advantage, and a safety feature, of inhalation sedation.

If, at any time during the procedure, the patient feels that they are getting too much or if they begin to feel uncomfortable, they should tell the doctor immediately and within seconds they can adjust the flow of gases, and the patient will feel more comfortable again.

At the conclusion of the dental treatment, the patient will once again receive 100% oxygen (for a minimum of three to five minutes). At the end of this time, the person should feel absolutely back to normal. If they still feel even a little bit sedated, the doctor should give the patient oxygen for a few more minutes.

Most dentists permit the fully-recovered N₂0-0₂ patient to leave their office unescorted and to resume their normal activities. In some situations where a patient recovers more slowly, they might be required to have an escort (friend or relative) drive them home.

N₂0-0₂ inhalation sedation is highly effective in the management of mild to moderate levels of dental fear. It also is an excellent technique in persons who are extreme gaggers. N₂0-0₂ usually eliminates or minimizes gagging in most patients. Finally, N₂0-0₂ is highly recommended for apprehensive patients who have medical problems such as angina pectoris, persons who have had a heart attack, or persons with high blood pressure, asthma, or epilepsy.

Inhalation sedation should not be used in persons who are claustrophobic or if the person is unable to breathe through their nose.