Nitrous oxide (otherwise known as N2O) is a gas most commonly used by dentists to relax patients during dental procedures. It was first used in an attempt to manage pain during a dental procedure in the year 1844. A dentist by the name of Horace Wells attempted to prove the suspected pain-relieving properties of nitrous oxide by inhaling the gas while having his own tooth removed. This experiment made Wells realize that nitrous oxide was not a strong pain-killer, yet it was very effective at inducing relaxation during dental procedures. After nitrous oxide was proven to relax patients, it became a popular tool for use in both dentistry and general anesthesia practices.
Nitrous oxide gas has no color, although it is said to have both a sweet smell and taste. When the gas is inhaled, it produces feelings of euphoria. The exact reasoning behind the euphoric feelings produced by nitrous oxide are not completely understood, as it appears that several different factors are in play to create the effect. Nitrous oxide, however, does temporarily decrease one's ability to feel nearly all sensations, which plays a large part in the production of an elated mental state. The most common sensations numbed by N2O are sensations of emotional and physical pain, hearing, and even the sensation of touch. When these sensations are taken away, most individuals slip into relaxation. Nitrous oxide also has the ability to allow those under its influence to feel completely uninhibited. Because of these effects of the gas, it is most commonly referred to as "laughing gas" or "happy gas."
Dentists are equipped with tanks full of nitrous oxide and tanks full of oxygen. When they begin to administer nitrous oxide to relax a patient, pure oxygen is first given through a mask-like apparatus, and the nitrous oxide is then mixed in with the oxygen until the proper amount of gas is breathed in by the patient. Upon first inhaling nitrous oxide, the patient quickly begins to feel the effects of the gas. It generally takes anywhere from 20 seconds to five minutes for nitrous oxide to reach the brain. When the gas reaches the brain, the patient begins to enter a relaxed state. Although the mental state of the patient is altered, they are still completely conscious and able to interact and cooperate with the dentist's requests.
After inhaling a small amount of nitrous oxide, patients most often experience the following side effects:
- Feelings of euphoria
- Feelings of amusement
- A generally "happy" disposition
- A deep sense of relaxation
- Feeling warm or overheated
- Numbness in the mouth or extremities
- Tingling limbs
- Muffled noises
In the event of uncomfortable side effects, the patient is capable of alerting the dentist of these effects. Upon alerting the dentist, the dentist will then adjust the level of nitrous oxide accordingly or provide the patient with pure oxygen until the side effects lessen or disappear. It generally takes about five minutes of breathing pure oxygen for the nitrous oxide to be eliminated from the bloodstream. After five minutes of oxygen, the patient should be back to a normal mental state, although motor skills can be affected for up to 15 minutes after nitrous oxide. For this reason, it is best for the patient to remain in the dental office for at least 15 minutes after receiving nitrous oxide if they are driving afterward.
Nitrous oxide, or laughing gas, is a safe way to manage anxiety during dental procedures for both adults and children when the gas is administered by a professional. Adult patients should discuss any concerns they may have about nitrous oxide with their dentist and inform their dentist of any medical conditions or daily medications before the dentist administers laughing gas to prevent any complications. Children are candidates for receiving nitrous oxide as well; however, they may be unable to keep a mask on their faces to receive the gas. Parents of children receiving nitrous oxide should discuss concerns and any medical conditions before treatment occurs with both the dentist and their child's pediatrician to avoid potential complications.
Certain conditions may require further consultation between a dentist and a patient's medical doctor to ensure the safety of the patient before administering nitrous oxide. These conditions include:
- Pregnancy: A dentist must speak to a pregnant patient's obstetrician before administering nitrous oxide to ensure that it is safe for both the mother and the fetus.
- Psychiatric conditions: If medication for a psychiatric condition is taken by a patient, it is important that they speak with their psychiatrist before receiving nitrous oxide to ensure that there are no drug interactions that will affect the patient's mental state.
- Prior substance abuse problems: Recovering alcoholics and those recovering from other forms of substance abuse should consult their drug counselor or psychiatrist before receiving any type of mind-altering substance. Chemicals that alter the mind, such as nitrous oxide, could lead to a relapse.
- Ear infection
- Sickle cell anemia
- Heart failure
- COPD (Chronic Obstructive Pulmonary Disease): Treatment with nitrous oxide requires that the patient inhale nitrous oxide through the nose. Those with breathing problems such as COPD, emphysema, or bronchitis should consult their physicians before receiving nitrous oxide.
- Recent surgeries or severe injuries: Patients who have had recent surgeries on the eyes or ears or patients who have recently suffered severe injuries, particularly head injuries, should consult their physician before scheduling a treatment with nitrous oxide.
- Allergic reaction to any medication
Reporting daily medications (including herbal supplements) as well as any underlying medical conditions to a dentist before nitrous oxide is administered is the best way prevent complications. It is also very important that patients discuss any concerns or questions they may have with their dentists before receiving nitrous oxide. Patients should also not hesitate to speak up and allow their dentist to know if they are uncomfortable or experiencing side effects while receiving nitrous oxide. Dentists strive to keep their patients relaxed and comfortable, and if they are aware of discomfort, they are able to quickly remedy the situation.