Trace amounts of gases unavoidably leak into room air during utilization of nitrous oxide. With chronic exposure, such as what dental personnel receive during daily administrations to patients, nitrous oxide is potentially toxic. Sources of leakage include: the nitrous machine itself, hoses, the nasal mask or nosepiece, and the patient’s mouth. Possible detrimental effects to dental personnel include: increased kidney and liver diseases, increased spontaneous abortion (miscarriage), increased cancer and decreased bone marrow. The incidences seem to be greater in females than in males.
Preventive measures should be taken in the dental office to minimize exposure. Primary control measures include:
Testing equipment for leakage and providing preventive maintenance
closed air value on nosepiece or preferably use of scavenging nose hood;
minimize patient conversation.
Manufactured devices for collection and disposal of gases.
outdoor ventilation system.
Air monitoring program.
Your dental supply representative can be consulted regarding specifications and cost involved in this protective equipment. The more frequently nitrous oxide is administered in a particular dental practice, the more essential these items become.
To complete your instruction in the administration of nitrous oxide, answer all questions on the self-examination that follows.
Note: A bibliography is provided for further information relevant to all topics included in this module.
AIDING IN THE ADMINISTRATION OF N2O Directions: Answer the following questions on a separate piece of paper to the best of your ability. You may use the module to look up needed information. Upon completion of the exam, review all responses to familiarize yourself with pertinent information.
What portion/functions of the CNS and ANS are affected by nitrous oxide?
How does oxygen travel through the respiratory system?
What changes in respiration/breathing are described by the following terms?
a. bradypnea e. eupnea
b. tachypnea f. anoxia
c. hyperpnea g. hypoxia
How does nitrous oxide travel through the respiratory system?
What effect does N2O have on the CNS and ANS?
What are possible side effects and adverse reactions of nitrous oxide and how can these be prevented?
What is the difference between anesthesia and analgesia?
What are the four stages of anesthesia and what reactions will a patient have in each stage?
What are the clinical manifestations observes in each plane of analgesia?
How can a clinician recognize that a patient is in deep plane two, approaching plane three of analgesia? What should be done when these signs and symptoms occur?
How are a patient’s respiration, blood pressure, pulse, and pupils affected by the administration of nitrous oxide when in plane two of analgesia and when in plane three of analgesia or light anesthesia?
When is the administration of nitrous oxide indicated for dental treatment?
When is the administration of nitrous oxide contraindicated for dental treatment?
Why are vital signs recorded prior to the administration of N2O?
How is the pulse rate obtained?
What are normal pulse rates for an adult patient and a child patient?
How is blood pressure taken? (describe the procedure in detail)
What is the normal blood pressure range for an adult patient?
What alterations in dental treatment should be made when the patient’s blood pressure is 140 to 160 systolic and/or 90 to 95 diastolic; 160 to 200 systolic and/or 95 to 115 diastolic; and greater than 200 systolic and/or greater than 155 diastolic?
How is the respiratory rate observed?
What are the normal respiratory rates for an adult patient and a child patient?
What should a dental professional do when a significant abnormality in vital sign(s) is noted?
What steps are taken during preanesthetic preparation?
What is a fail-safe system?
How should a clinician explain the procedures and effects of nitrous oxide to a patient who is going to receive it?
What steps are followed during the administration of nitrous oxide?
How is the ratio (percentage) of oxygen to nitrous oxide computed if 6 liters of O2 and
2 liters of N2O are administered?
What is the maximum ratio of O2 to N2O that is recommended for administration during routine dental therapy?
How and why is a patient oxygenated prior to dismissal?
Why is a complete and accurate legal chart entry essential following nitrous oxide administration?
What points should be recorded in a complete and accurate legal chart entry following administration of nitrous oxide?
How does the Idaho State Board of Dentistry define “aiding in the administration” of nitrous oxide?
What are some of the variables which have had an effect on nitrous oxide research?
What preventative measures should be taken in the dental office to minimize occupational exposure to nitrous oxide?
Malamed, S.F. Sedation: A Guide to Patient Management. C.V. Mosby Co., St. Louis, 1985.
Malamed, S.F. Handbook of Medical Emergencies in Dental Practice. C.V. Mosby Co., St. Louis, 1989.
Bennett, C.R. Conscious Sedation in Dental Practice. C.V. Mosby Co., St. Louis, 1978.
Langa, H. Relative Analgesia in Dental Practice. W.B. Saunders Co., Philadelphia, 1976.
Henry, R.J. and Quock, R.M. “Cardiovascular influenced of nitrous oxide in spontaneously hypertensive rats.” Anesth. Prog., 36(3):88-92, 1989.
Becker, D.E. “The respiratory effects of drugs used for conscious sedation and general anesthesia.” JADA, 119:153-6, July 1989.
Jastek, J.T. “Issues of pain and anxiety control training and continuing education.” J. Dent. Educ., 53 (5/6):293-6, 1989.
“Dental Phobia: Conquering fear with trust.” JADA, 119:593-8, Nov. 1989.
Weinstein, P., et al. “The use of nitrous oxide in the treatment of children: results of a controlled study.” JADA, 112:325-331, March 1986.
“Conscious Sedation: Benefits and risks.” JADA, 109:546-557, Oct. 1984.
Duncan, G,H, and Moore, P. “Nitrous oxide and the dental patient: a review of adverse reactions.” JADA, 108:213-9, Feb. 1984.