1. The most popular sedative Fadi Kass DMD, Msc, FRCD(c)‏
1426 McPhillips St
Winnipeg, MB
888-KIDS
Nitrous Oxide:
The most popular sedative
Fadi Kass DMD, Msc, FRCD(c)‏
November 15, 2008

2. Some statistics: United States 89%1 and 86%2 of pediatric dentists
35%3 of general dentists
Manitoba
52 out of 610 registered dentists (8.5%)‏
4 out of 16 Pediatric dentists (25%)‏

3. MDA stipulates . . . Have taken a nitrous licensing course
University of Alberta
Dalhousie University
Site audit for the initial setup
Office audit every 3 years to upkeep your initial site audit allowing the use of nitrous

4. Some history . . .
Discovered in 1772 but primarily used as recreational drug

5. Pertinent history . . .
In 1884, Horace Wells first dentist to recognize its value
Saw it at a show
Extracted own tooth next day

6. Benefits of Nitrous Safe and effective
Increase patient comfort and enjoyment
Visually shields child's eyes from work
Potential practice building tool
Short recovery time
Short duration of onset
Easy to administer

7. What is it?
N2O
Colorless
Odorless except for faint sweet smell

8. 4How does it work? Exact mechanism unknown
Widely accepted that the analgesic effect is mediated through interaction with opioid receptors.
The anxiolytic effect is mediated through interaction with the GABA-A receptors. Closely resembles the effect of ethanol.

9. 5How it works . . . Rapidly absorbed upon inhalation
As a result of lower tissue/blood partition coefficients, the equilibration of nitrous oxide in most tissues occurs rapidly
Nitrous oxide is not metabolized in the body.
The blood/gas partition coefficient is low and most of the inhaled nitrous oxide is rapidly eliminated through the lungs, though small amounts diffuse through the skin

10. Equipment . . .
Need to deliver a mixture of nitrous oxide and oxygen from the the tanks to the child's lungs

11. Equipment . . .
Modern equipment employ “fail-safe” mechanisms that allow a minimum of 30% oxygen to be used.
By contrast, air we breath is 22% oxygen
Body is never oxygen starved

12. Equipment . . . Use of digital delivery units
Digital units deliver pure oxygen during “flush” function instead of simply mixing more nitrous to the bag

13. 1Monitoring equipment
Clinical observation of the patient’s responsiveness, color, and respiratory rate and rhythem must be performed.
According to the American Academy of Pediatrics, if nitrous is used with any other sedatives, monitoring should be done in accordance to the protocol of deep sedation
According to the American Academy of Pediatric Dentistry, oxygen analyzers use in the office are only a recommendation unless nitrous is used in concentrations greater than 80%.

15. Does nitrous work?

16. My experience . . .
Anecdotally, based on case selection, nitrous use seems to assist significantly.
Children under 3 are not candidates for nitrous as they are pre-cooperative
3-6 yr old patients are only good candidates if you think they will wear the nose piece without panicking
6 yrs + are ideal candidates as they are capable of understanding instructions given by the clinical team

17. Biggest benefit for me . . .

18. Fear reduction using nitrous4
Study looking at two groups of children
Behavior Management
Behavior Management + Nitrous
Anxiety scores were significantly lower
At semi annual check-ups, Nitrous group did significantly better
Concluded that nitrous helps children lower anxiety levels during a long period after treatment

19. Ideal flow rate Range between 5-6 L/min
Look for bag movement with inspiration / expiration

20. Percentage of Nitrous? Depending on the patient Ranges between 25%-50%
The mean alveolar concentration of N2O considered the ED50 for general anesthesia (the dose at which 50% of patients will experience anesthesia) is 105%.
Nitrous alone can not be used to bring on general anesthesia.

21. 3Normal distribution curve

22. Prepare the child
When child receives nitrous for first time, the dentist or assistant should explain what they will feel
Tingling of hands and feet
Slight floating sensation
Chest is going to feel funny
General disconnect (“weird”) feeling
THEY ARE ALWAYS IN CONTROL
THEY WILL NOT FALL ASLEEP

23. If the nitrous levels are too high
At correct therapeutic levels, it will be a positive experience for most patients
If the nitrous levels are too high
Experience slight/severe nausea
Uncontrollable giggling
May even experience a greater sense of anxiety

24. Sequence . . . Start with 100% oxygen
Progress to 25% nitrous over 2 mins
Increase by 5% every 30 seconds until ideal levels area reached
Flush oxygen when giving local
Restart back to ideal level for procedure assuming rubber dam use
Finish with 3-5 mins at 100% oxygen

26. Problems with nitrous use . . .

27. Diffusion hypoxia
Occurs when the nitrous is discontinued at the end of a procedure which produces a “hang over” type effect
Rapid diffusion of nitrous from the blood back into the alveoli results in displacement of oxygen and a drop in pO2.
This can be easily avoided by breathing 100% O2 for 3-5 mins.

28. Contraindications Women who are in the first trimester of pregnancy
Some evidence linking its use to a higher risk of miscarriage in dental assistants
Persons with chronic obstructive pulmonary disease (COPD)
Bronchitis or emphysema related to cigarette smoke
PO2 is their primary stimulant for respiration
Patients undergoing bleomycin sulfate treatment.
Anticancer drug

29. Thank You

30. Bibliography
Wilson S. A survey of the American Academy of Pediatric Dentistry membership: nitrous oxide and sedation. Pediatr Dent Jul-Aug;18(4):
Adair SM, Waller JL, Schafer TE, Rockman RA. A survey of members of the American Academy of Pediatric Dentistry on their use of behavior management techniques. Pediatr Dent Mar-Apr;26(2):
Malamed SF, Clark MS. Nitrous oxide-oxygen: a new look at a very old technique. J Calif Dent Assoc May;31(5): Erratum in: J Calif Dent Assoc Jun;31(6):458.
Veerkamp JS, Gruythuysen RJ, Hoogstraten J, van Amerongen WE. Anxiety reduction with nitrous oxide: a permanent solution? ASDC J Dent Child Jan-Feb;62(1):44-8
Reynolds JE. Martindale: The Extra Pharmacopoeia. The Pharmaceutical Press: London