Presentation on theme: "Nitrous Oxide Sedation in Pediatric Dentistry"— Presentation transcript:
1 Nitrous Oxide Sedation in Pediatric Dentistry Dr.S.E.Jabbarifar 2009
2 History of N2O 1793 - Joseph Priestly invented N2O Initially used as an anesthetic agent in 1844.Dr. Horace Wells
3 N2O Commonly Used (and misused) 88% of Pediatric Dentists use N2O, and about 58% of general dentists use N2O.Deadheads inhaling N2O from a balloon.
4 Purpose of Nitrous Oxide Sedation Reduce fear, apprehension, or anxietyRaise pain reaction thresholdReduce fatigue
5 Fear Reduction & N2OOne group treated with behavior management only; other group with behavior management and N2O.Dental treatment of highly fearful children is carried out more successfully with N2O during the first few sessions.N2O is thus a valuable aid for making highly fearful children treatable quickly.Veerkamp, et al, J Dent Child,May-June 1993
6 Fear Reduction & N2OWhen highly anxious children are treated with nitrous oxide for a number of consecutive sessions, their anxiety remains significantly lower during a following control period, even without use of nitrous oxide.Veerkamp, et al, J Dent Child,Jan-Feb 1995
9 Four Stages of Anesthesia Analgesiapatient is consciousreflexes are intactDeleriumSurgical AnesthesiaRespiratory ParalysisThe patient is unconscious in Stages 2, 3, and 4.
10 AnalgesiaIn analgesia stage, the patient is conscious, has all vital reflexes intact, can communicate and cooperate with the dentist, and quickly returns to a normal state following a few minutes of oxygenation.
11 Four Plateaus of Analgesia Paresthesia - tingling of hands, feetVasomotor - warm sensationsDrift - euphoria, pupils centrally fixed, sensation of floatingDream - eyes closed but will open in response to questions, difficulty in speaking, jaw sags open
12 N2O Should Be Used To: Ease fears and anxieties Aid in the treatment of special patientsIncrease tolerance for longer appointmentsRaise the pain reaction threshold
13 N2O Should Not Be Used To: Control defiant or uncontrolled behaviorControl pain by replacing local anesthesiaReplace poor techniques of behavior management
14 Uptake and Saturation of N2O Highly Perfused TissuesLungsBloodLess Uptake N2O from LungsEffective PP in BrainPROBLEMS!!!Increase Lung N2O ConcentrationTissue Saturation
15 Signs of Saturation Reminding child continuously to hold mouth open No response to questionsAgitationSweatingNauseaUnconsciousnessMonitor Frequently
17 Inhalation Analgesia Permits - State of Nebraska Portable oxygen tankDelivery system that delivers a maximum of 80% N2OMedical historyPhysical evaluation ("...vital signs such as pulse, blood pressure, respirations, temperature and weight..."Oral pharyngeal airways availableEmergency drugs
18 Elimination of N2O Rapid Primarily through the lungs Small amount through skin, sweat glands, urine, and intestinal gas
19 Diffusion Hypoxia High outpouring of N2O Dilutes available oxygen in lungsVentilate the patient for 3 to 5 minutes to prevent diffusion hypoxia!
20 Effects on Systems CNS - primary system effected by N2O Respiratory respiratory rate increasedecrease tidal volumeN2O potentiates respiratory depression with concommitant use of narcotics, barbiturates, or other sedatives
21 Effects on Systems Cardiovascular normally, no meaningful changes in heart rate or pressuremyocardial depression with cardiac decompensation (congestive heart failure)patients with ischemic heart disease without decompensation may benefit from N2O
22 Myocardial Depression with N2O Use in CHF Patients
23 Effects on Systems Fetal 1967 (Vaisman) - report showing increased incidence of spontaneous abortion among femal Russian anesthesiologists1980 (Cohen, et al) - report showing increased spontaneous abortion rates (2.3) for DAs and unexposed wives of DDSs who used N2O in their practices; also higher rates of liver, kidney and neurological disease
24 Effects on Systems Fetal (cont.) 1992 (Rowland, et al.) - demonstrated reduced fertility among female DAs exposed to ambient levels of unscavenged N2O for longer than five hours per week; the concentration and length of exposure that produce any of these effects remain undocumented.
25 Chronic Exposure to N2O“Long-term (chronic) exposure to nitrous oxide in sufficient concentrations can produce irreversible, toxic changes, and should be a concern for dental personnel working in environments in which nitrous oxide is administered to patients.”Howard, JADA, March 1997
27 Neurological Symptoms of Chronic Exposure Uh, whaa ja’ say????Loss of concentrationNumbness and paresthesiaAtaxiaImpotenceLoss of bladder controlLoss of bowel sphincter control
28 Safe Concentrations of N2O OSHA - not establishedNIOSH - recommended exposure limit (REL) 25ppm during administrationsACGIH (American Conference of Governmental Industrial Hygienists) 50 ppm threshold limit value (TLV) over 8 hour TWA (time weighted average)
29 Safe Concentrations of N2O Nitrous Oxide GuidanceADA met with OSHA's second in command, Deputy Assistant Secretary James Stanley, Sept. 18 after learning that a draft OSHA "technical guidance" document on anesthetic gases apparently imposes on dental offices a nitrous oxide level of 25 ppm, a level technologically out of reach and far below that associated with adverse health effects. ADA pointed out that the Association's expert panel, which met Sept. 12 and 13 and included an OSHA engineer, agreed the 25 ppm level is unjustified by scientific data. ADA will submit written comments on the OSHA draft by the end of October. (September 26)
30 Safe Concentrations of N2O ADA - has not proposed a permissible exposure limit, but emphasizes the routine use of scavenging equipment
31 N2O ScavengingDeveloped out of a concern regarding possible health consequences and psychomotor influencesADA states that scavenging equipment should be:used to reduce ambient N2Oeffective regardless of heating and air conditioning system in useable to achieve N2O standards recommended by NIOSH and OSHA
32 Controlling N2O in the Operatory Monitoring N2O concentrationAir samples from two areasroom air - infrared spectrophotometerworker breathing zone - passive dosimeterHoward, JADA, March 1997
33 Controlling N2O in the Operatory Engineering controlsInspectionequipment for wear, cracks, tearstest connectionsScavenging systemno system currently accepted by ADAflow rate of 45 L/min vacuum rateHoward, JADA, March 1997
34 Controlling N2O in the Operatory VentilationFresh air inlets - ceilingReturn air vents - floor levelLocation of ventilation system exhaustAir exchange rate (>10/hr)Howard, JADA, March 1997
35 Controlling N2O in the Operatory Work PracticesInspect equipment every dayUse scavenging systemInstruct patient to refrain from mouth breathing and talkingBag should collapse and expand as the patient breathesAfter administration, flush the system 100% O2.Howard, JADA, March 1997
36 Controlling N2O in the Operatory MaintenanceInspect and test for leaks (soap)Document results of tests and actions takenAll repairs done by authorized dealersHoward, JADA, March 1997
37 N2O Scavenging Factors of scavenging effectiveness auxilliary evacuationrate of evacuation of scavenging deviceoperatory ventilationuse of air sweep fansreduced concentration of delivered N2Opoor patient behaviorcertain procedures (local anesthesia)improper administrationloose connections
39 Preparation of Patient Patient in reclined positionUse TSDDescribe sensations in advanceThis is how its gonna be, kid...
40 Administration of N2O Medical history & vital signs 5 - 6 liters O2 Increase N2O gradually; watch for stages of analgesiaMaintenance about %Reduce N2O with long proceduresRecord N2O levels in the chart3 - 5 minute O2 flushRapid induction (surge) technique
42 Complications/Precautions Vomiting - due to:overdosageprolonged administrationpre-existing GI infection, influenzahistory of motion sickness or vomiting (use anti-emetic)impurities in the delivery system (rare)If vomiting occurs, turn patient to the side and use HVEPrevent vomiting by close observation of patient
43 Hallucinations Always have an assistant present! Complications/PrecautionsAlways have an assistant present!
44 Complications/Precautions Mild rhinitis or colds are not absolute contraindicationsContraindicated in patients with a depressed respiratory systemchronic emphysematuberculosismultiple sclerosisremember, N2O will potentiate drugs that depress the respiratory system
45 Complications/Precautions Contraindicated in patients with blocked eustachian tube, pneumothorax, pneumoperitoneum, and pneumopericardiumContraindicated in the first trimester of pregnancy
46 Complications/Precautions Other possible contraindications:severe cardiac diseasehyperthyroidismuncontrolled diabetessickle cell anemiasevere asthmatic conditions