Journal of Pharmacy And Bioallied Sciences

: 2015  |  Volume : 7  |  Issue : 5  |  Page : 248--250

Nitrousoxide as a conscious sedative in minor oral surgical procedure

Rakesh Mohan, Vigil Dev Asir, Shanmugapriyan, Vijay Ebenezr, Abu Dakir, Balakrishnan, Jeffin Jacob 
 Department of Oral and Maxillofacial Surgery, Sree Balaji Dental College and Hospital, Chennai, Tamil Nadu, India

Correspondence Address:
Dr. Rakesh Mohan
Department of Oral and Maxillofacial Surgery, Sree Balaji Dental College and Hospital, Chennai, Tamil Nadu


Nitrous oxide (N 2 O) is the most commonly used inhalation anesthetic in dentistry and is commonly used in emergency centers and ambulatory surgery centers as well. When used alone, it is incapable of producing general anesthesia reliably. However, as a single agent, it has an impressive safety and is excellent for providing minimal and moderate sedation for apprehensive minor oral surgical procedure. In this article, action of N 2 O in overcoming the anxiety and pain of the patient during the minor oral surgery and its advantages and disadvantages, have been reviewed.

How to cite this article:
Mohan R, Asir VD, Shanmugapriyan, Ebenezr V, Dakir A, Balakrishnan, Jacob J. Nitrousoxide as a conscious sedative in minor oral surgical procedure.J Pharm Bioall Sci 2015;7:248-250

How to cite this URL:
Mohan R, Asir VD, Shanmugapriyan, Ebenezr V, Dakir A, Balakrishnan, Jacob J. Nitrousoxide as a conscious sedative in minor oral surgical procedure. J Pharm Bioall Sci [serial online] 2015 [cited 2021 Oct 27 ];7:248-250
Available from:

Full Text

Nitrous oxide (N 2 O) has been available since the mid-1800s but only gained general acceptance as dental inhalation sedation in the second half of the 20 th century. Its use accelerated in the 1970s and 1980s, leveled off for a brief period because of environmental concerns, and then continued to increase into the 21 st century. The purposes of this article are to: Review the indications and contraindications and importance of N 2 O in minor oral surgical procedures.

 What is Nitrous Oxide?

Nitrous oxide is a colorless and virtually odorless gas with a faint, sweet smell. It is an effective analgesic/anxiolytic agent causing central nervous system depression and euphoria with little effect on the respiratory system. [1]

 Nitrous Oxide in Oral Surgery

Patient anxiety has always been a major issue in dental offices. This course reviews guidelines for use of N 2 O for the dental practitioner and dental staff to manage anxiety and pain.

Dentists have expertise in providing anxiety and pain control for their patients. Although anxiety and pain can be modified by psychological techniques, in many instances pharmacological approaches are required. [2] Analgesia/anxiolysis is defined as diminution or elimination of pain and anxiety in a conscious patient. [3] The patient responds normally to verbal commands. All vital signs are stable, there is no significant risk of losing pro-tective reflexes, and the patient is able to return to preprocedure mobility. In children, analgesia/anxiolysis may expedite the delivery of procedures that are not particularly uncomfortable, but require that the patient not move. [3] It also may allow the patient to tolerate unpleasant procedures by reducing or relieving anxiety, discomfort, or pain. The outcome of pharmacological approaches is variable and depends upon each patient's response to various drugs. The clinical effect of nitrous oxide/oxygen inhalation, however, is more predictable among the majority of the population.


The patient should be advised to avoid the heavy meal prior to the useThe patient is requested to void if necessary, prior to treatmentPatients with contact lenses should be removed as gas leaks around the bridge of the nose may produce drying of the eyes.

 Techniques of Administration

Nitrous oxide - oxygen sedation will always begin and end with the patient receiving 100% oxygen. Then, slowly allowed to breathe. A flow rate of 5-6 L/min generally is acceptable to most patients. The flow rate can be adjusted after observation of the reservoir bag. The bag should pulsate gently with each breath and should not be either over or underinflated. Introduction of 100% oxygen for 1-2 min, followed by titration of N 2 O in 10% intervals is recommended. During nitrous oxide/oxygen analgesia/anxiolysis, the concentration of N 2 O should not routinely exceed 50%. Increasing amounts of N 2 O until the desired effect is achieved. It is important that the patient be reminded to breathe through the nose in order for the gas to work. The patient should be questioned as to how they are feeling to ensure an optimal level of nitrous is being administered. Therapeutic levels will vary from patient to patient. If the nitrous level being administered is too low, the patient will not be receiving an effective anxiolytic dose. If the nitrous level is too high, unwanted side-effects may occur.

Studies [4],[5] have shown that children desaturate more rapidly than adolescents, and administering 100% oxygen to the patient for 3-5 min once the nitrous oxide in a closed system has been terminated is important. [4]

The objectives of nitrous oxide/oxygen inhalation include

Reduce or eliminate anxietyReduce untoward movement and reaction to dental treatmentEnhance communication and patient cooperationRaise the pain reaction thresholdIncrease tolerance for longer appointmentsAid in treatment of the mentally/physically disabled or medically compromised patientReduce gaggingPotentiate the effect of sedatives.


A fearful, anxious, or obstreperous patientCertain patients with special health care needsA patient whose gag reflex interferes with dental careA patient for whom profound local anesthesia cannot be obtainedA cooperative child is undergoing a lengthy dental procedure.


Chronic obstructive pulmonary diseasesSevere emotional disturbances or drug-related dependencies [6]First trimester of pregnancy [7]Treatment with bleomycin sulfate [8]Methylenetetrahydrofolate reductase deficiency. [9]

Whenever possible, appropriate medical specialists should be consulted before administering analgesic/anxiolytic agents to patients with significant underlying medical conditions (e.g. severe obstructive pulmonary disease, congestive heart failure, sickle cell disease, [10] acute otitis media, recent tympanic membrane graft, [11] acute severe head injury [12] ).


Easy to administerOnset of action is rapidN 2 O has bland, pleasant, nonirritating orderRapid uptake and elimination of N 2 O ensures that no hangover effect is experiencedRecovery is fastTitration is possibleThere is a wide margin of safetyThere is cardio-respiratory stabilityNausea and vomiting are uncommonReflex integrity is maintainedNo preparation of patient is requiredNo need for any escort.


Equipment is expensivePatient must be able to breathe through the noseInterference of the nasal hood with injection to anterior maxillary region.


Nitrous oxide/oxygen anesthesia is used in a standard way in dentistry and medicine. And a review of the standards on a regular basis is invaluable to maintain the highest standard of care. Professional use and administration of N 2 O is a tried and true method to managing patients' anxiety for dental procedures. The overall patient experience is enhanced by careful and professional use of this practice-building anesthetic gas. Dental team members must adhere to the best clinical protocols and know the standard of care to ensure absolute safety for the patient and to minimize exposure to themselves. N 2 O is safe and effective for use by qualified dental professionals in a wide variety of situations requiring pain and anxiety management in the minor oral surgical procedures.


1Paterson SA, Tahmassebi JF. Paediatric dentistry in the new millennium: 3. Use of inhalation sedation in paediatric dentistry. Dent Update 2003;30:350-6, 8.
2American Dental Association. Position statement: The use of conscious sedation, deep sedation and general anesthesia in dentistry. Available from: [Last accessed on 2008 Nov 24].
3American Society of Anesthesiologists Task Force on Sedation and Analgesia by Non-Anesthesiologists. Practice guidelines for sedation and analgesia by non-anesthesiologists. Anesthesiology 2002;96:1004-17.
4Patel R, Lenczyk M, Hannallah RS, McGill WA. Age and the onset of desaturation in apnoeic children. Can J Anaesth 1994;41:771-4.
5Kinouchi K, Tanigami H, Tashiro C, Nishimura M, Fukumitsu K, Takauchi Y. Duration of apnea in anesthetized infants and children required for desaturation of hemoglobin to 95%. The influence of upper respiratory infection. Anesthesiology 1992;77:1105-7.
6Clark MS, Brunkick AL. Nitrous Oxide and Oxygen Sedation. 3 rd ed. St Louis, Mo: Mosby; 2008. p. 94.
7Rowland AS, Baird DD, Shore DL, Weinberg CR, Savitz DA, Wilcox AJ. Nitrous oxide and spontaneous abortion in female dental assistants. Am J Epidemiol 1995;141:531-8.
8Fleming P, Walker PO, Priest JR. Bleomycin therapy: A contraindication to the use of nitrous oxide-oxygen psychosedation in the dental office. Pediatr Dent 1988;10:345-6.
9Selzer RR, Rosenblatt DS, Laxova R, Hogan K. Adverse effect of nitrous oxide in a child with 5,10-methylenetetrahydrofolate reductase deficiency. N Engl J Med 2003;349:45-50.
10Ogundipe O, Pearson MW, Slater NG, Adepegba T, Westerdale N. Sickle cell disease and nitrous oxide-induced neuropathy. Clin Lab Haematol 1999;21:409-12.
11Fish BM, Banerjee AR, Jennings CR, Frain I, Narula AA. Effect of anaesthetic agents on tympanometry and middle-ear effusions. J Laryngol Otol 2000;114:336-8.
12Moss E, McDowall DG. ICP. increases with 50% nitrous oxide in oxygen in severe head injuries during controlled ventilation. Br J Anaesth 1979;51:757-61.