International Journal of Dental and Health Sciences Volume 01,Issue 02 Review Article

NITROUS OXIDE INHALATION SEDATION IN PEDIATRIC DENTISTRY: A REVIEW

Garima Malhotra1, Sambhav Jain2 1. Post Graduate, Department of Pedodontics and Preventive Dentistry, Teerthanker Mahaveer Dental College & Research Centre, Moradabad, India 2. Post Graduate, Department of Periodontology, Teerthanker Mahaveer Dental College & Research Centre, Moradabad, India

ABSTRACT:

Modern general and conscious sedation procedures are predictable, effective, and safe with appropriate patient selection, drugs and techniques. The use of conscious sedation in pediatric dentistry in office-based settings continues to increase. Nitrous oxide is the most commonly used inhalation anesthetic (sedative) used in dentistry, and has withstood the test of time with an excellent safety record. It reduces anxiety, pain, and memory of the treatment experienced, and is a valuable component of the armamentarium available to clinicians.

Key words: Conscious Sedation, Inhalation Sedation, Nitrous Oxide, Oxygen, Pediatric Dentistry, Uncooperative child.

INTRODUCTION: alternative for the dentist to adopt and manage dental anxiety, stress and fear Providing comprehensive oral care to related to dental procedure and avoid young patients is a unique challenge. Child unpleasant and unproductive behavior can never become an alibi for a confrontation with the child [1]. sub-standard work in the mouth. However, in spite of all its technical and Pharmacological management may materialistic advances, behaviour science divided into three categories, conscious still seems to provide limited options for sedation, deep sedation, and general its uncooperative young children. anaesthesia, but due to increased risks Guidance of children’s behaviour in and costs associated with deep sedation dentistry has been limited to an art rather and general anaesthesia, conscious than a science. It is no wonder that today sedation has emerged as a preferable there are more and more dentists are technique, it is a minimally to moderately afraid of children than children afraid of depressed level of consciousness that dentists, Henceforth pharmacological retains the patient’s ability to intervention becomes an important independently and continuously maintain

*Corresponding Author Address: Dr. Garima Mahrotra, Department of Pedodontics and Preventive Dentistry, Teerthanker Mahaveer Dental College & Research Centre, Moradabad, India E-mail: [email protected] Mahrotra G. et al., Int J Dent Health Sci 2014; 1(2): 161-169 an airway and respond appropriately to  “A technique in which the use of a physical stimulation and verbal command. drug or drugs produces a state of This level of sedation may be depression of the central nervous accomplished by inhalation, oral and system enabling treatment to be parenteral administration of a single carried out, but during which sedative drug or by combining sedative verbal contact with the patient is agents. Sedative agents often include maintained throughout the period nitrous oxide‐oxygen, narcotics, of sedation. The drugs and benzodiazepines, chloral hydrate, techniques used to provide barbiturates as well as antihistamines. [2] conscious sedation for dental treatment should carry a margin of According to Shapiraet al [3], the ideal safety wide enough to render loss paediatric dental sedative should possess of consciousness unlikely”. [4] a number of qualities, including safety, minimum respiratory depression, adequate sedation, minimal patient movement, early onset of drug action,  “A medically controlled state of and adequate working time. Inhalation depressed consciousness that sedation should be the first choice for allows the protective reflexes to dental patient who are unable to tolerate be maintained; retains the fear and stress of dental treatment. patient’s ability to maintain a Nitrous oxide is delivered with oxygen as a patent airway independently and titrated dose via a nasal mask. It is cost continuously; and permits an effective alternative to general appropriate response by the anesthesia. [4] Inhaled nitrous oxide also patient to physical stimulation or produces anxiolytic and mild analgesic verbal command, e.g., ‘Open your [6] effects. [5] The present review article eyes’.” discusses the nitrous oxide inhalation Inhalation Sedation with Nitrous Oxide: conscious sedation in paediatric dentistry. Drugs used for pediatric inhalation Definition Of Conscious Sedation: sedation includes Nitrous oxide and Oxygen gas.  “Conscious sedation is a minimally to moderately depressed level of NITROUS OXIDE consciousness that retains the patient’s ability to independently Nitrous oxide is the only inhalation agent and continuously maintain an currently in routine use of conscious airway and respond appropriately sedation in dental practice. It was to physical stimulation and verbal discovered by Joseph Priestly in 1772 and command”[2] first used as an anesthetic agent for dental exodontia by in 1844. Nitrous oxide has been used as the basic

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Mahrotra G. et al., Int J Dent Health Sci 2014; 1(2): 161-169 constituent of gaseous anesthesia for the be separate from, and additional to, the subsequent 160 years, demonstrating its supply kept for use in the management of acceptability and usefulness. Nitrous emergencies. Oxygen will sustain and oxide is a colorless, faintly sweet smelling enhance combustion and therefore no gas with a specific gravity of 1.53. It is naked flames should be allowed in an area stored in light blue cylinders in liquid form where oxygen is being used. [7] at a pressure of 750 pounds per square inch (43.5 bar). [7]

Nitrous oxide is a gas with anxiolytic and sedative effects combined with varying degree of analgesia and muscle relaxation. Recent research suggests that both GABA a and NMDA-receptors are affected by nitrous oxide [8,9]. Nitrous oxide when administrated to patients for inhalation must be given in a mixture with oxygen (30% or more) to safeguard the patient’s oxygen supply. Nitrous oxide is non-irritant to the respiratory tract, has a low tissue solubility, and a minimum alveolar concentration (MAC) value of more than one atmosphere. Therefore nitrous oxide has a rapid onset, a fast recovery (both within minutes) and is a poor anesthetic. [6] Inhalation Sedation Apparatus OXYGEN Indication of Nitrous Oxide Sedation: Oxygen is not a sedating agent, however,  Most patients requiring sedation are inhalation sedation agents is always those with a simple, genuine fear or delivered in an oxygen-rich mixture phobia of dental treatment. containing a minimum of 30% oxygen by volume. Oxygen is stored as a gas in black  Children can present particular cylinders with white shoulders, at an problem & often require very careful initial pressure of 2000 pounds per square handling inch (137 bar). Because it is a gas under pressure, the gauge on the inhalational  Patients with mild systemic disorders sedation machine will give an accurate such as controlled hypertension, representation of the amount of oxygen angina which may be exacerbated by contained in the cylinder. The oxygen the stress of dental treatment supply used for inhalation sedation should represent a medical indication. 163

Mahrotra G. et al., Int J Dent Health Sci 2014; 1(2): 161-169  Patient with neuromuscular disorders  First trimester of pregnancy: such as spasticity, Parkinsonism & Teratogenicity [10] involuntary movement conditions Patient Assessment: often wishes to cooperate but physically cannot. A useful means of estimating fitness for sedation is to use the classification system  Dentally related problems such as introduced by the American society of gagging & trismus, persistent fainting anesthesiologists (ASA). In this system, & moderately difficult or prolonged patients are allocated to specific grades surgery. [7] according to their medical status and Contraindication Of Nitrous Oxide operation (or sedation) risk. The Sedation: classification uses six grades as follows:

 Moderate/severe learning ASA 1: fit and healthy disability: Inability to tolerate the ASA 2: mild systemic disease (for example, nasal mask and cooperate with well controlled hypertension, diabetes, nasal breathing , )  Severe anxiety: Inability to tolerate ASA 3: severe systemic disease which the nasal mask and cooperate with limits lifestyle, but not incapacitating (for nasal breathing example, poorly controlled epilepsy  Chronic obstructive pulmonary diabetes or asthma) disease: Theoretical risk of ASA 4: incapacitating systemic disease respiratory failure when exposed which is a constant threat to life to high concentrations of oxygen ASA 5: life-threatening systemic disease,  Nasal obstruction: For example, death likely within 48 hours nasal polyps, deviated nasal septum ASA 6: A declared brain dead patient whose organs is being removed for donor  Patients treated with bleomycin [6,11,] purposes. (chemotherapy agent): Patients predisposed to respiratory failure Preoperative Fasting: when exposed to high The ASA guidelines for minimum fasting concentrations of oxygen periods for infants and children  Patients who have had recent *Clear fluids: = 2 hours retinal surgery: Risk of raised pressure within the eye and Clear liquids include, but are not limited damage to sight to; water, fruit juices without pulp, carbonated beverages, clear tea and black

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Mahrotra G. et al., Int J Dent Health Sci 2014; 1(2): 161-169 coffee. The volume of liquid ingested is finger and toes in the young child. less important than the type of liquid Concentrations of nitrous in excess of 50% ingested. are usually contraindicated for dental office sedation. When the dental injection Breast milk: = 4 hours is completed, the nitrous oxide level Nonhuman milk, infant formula = 6 hours should be reduced to 30 to 35% for a maintenance dose during the dental *Solids, Light meal = 6 hours treatment; alternatively, 100% oxygen may be administrated when the nitrous "The recommendations for solid food oxide is only needed for behaviour were reportedly made with insufficient management related to the dental published data. A typical light meal injection. includes toast and clear fluids. Fried and Fatty foods may prolong gastric emptying. Upon termination of nitrous oxide The amount and type of foods must be administration, inhalation of 100% oxygen [12] considered. not less than 3 to 5 minutes is recommended. This allows rapid diffuse of Technique: nitrous oxide from the venous blood into The nose piece should be introduced with the alveolus while maintaining instructions to breathe nasally. The oxygenation, enabling the patient to minimal finger pressure under the lower return without incident to pretreatment lips to produce an oral seal and gentle activities. Inadequate oxygenation may tapping of the nose-piece can be helpful produce such postoperative side effects as to encourage nasal breathing in the young nausea, light headedness or dizziness, all child. of which can be reversed with the continued oxygen administration. Nitrous After stabilization of the nose- oxide should be considered an adjunct to piece and delivery of 100% oxygen for 3 to aid in management of minimal anxiety in 5 minutes the N O level should be 2 the child capable of cooperating in the increased to 30-50 % and administered for dental chair. [13] 3 to 5 minutes for the introduction period. While administrating the nitrous oxide, the dentist should talk gently to the child to promote relaxation and reinforce cooperative behavior. Asking older children and adults if they feel tingling sensation in the finger and in the toes are appropriate for verification of early signs of central nervous system (CNS) effects. An indication of such CNS effect would be minimal or continual movements of the

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Mahrotra G. et al., Int J Dent Health Sci 2014; 1(2): 161-169 MONITORING:

A dentist, or at the dentist’s direction, an appropriately trained individual, must remain in the operatory during active dental treatment to monitor the patient continuously until the patient meets the criteria for discharge to the recovery area. The appropriately trained individual must

be familiar with monitoring techniques and equipment. Monitoring must include: Child with Inhalation Sedation Unit • Oxygenation: Summary of Steps In Nitrous Oxide/Oxygen Administration: – Color of mucosa, skin or blood must be evaluated continually. 1. Full medical and dental history – Oxygen saturation by pulse oximetry 2. Informed, written consent may be clinically useful and should be considered. 3. Screening and assessment of health status • Ventilation:

4. Measurement of vital signs – The dentist and/or appropriately trained individual must observe chest excursions 5. Airway evaluation continually. 6. Patient seated in the operating chair – The dentist and/or appropriately trained 7. Titration of nitrous oxide using a nasal individual must verify respirations hood with scavenger continually.

8. Maintenance of desired level of • Circulation: sedation – Blood pressure and heart rate should be 9. Use of a pulse oximeter for patients evaluated pre-operatively, post- receiving more than 50% nitrous oxide operatively and intra-operatively as necessary (unless the patient is unable to 10. Administration of pure oxygen for tolerate such monitoring). three to five minutes after completion of the procedure and termination of Documentation: An appropriate sedative sedation, or longer if necessary until the record must be maintained, including the patient feels completely normal again names of all drugs administered, including local anesthetics, dosages, and monitored 11. Discharge of patient with written physiological. [14] instructions

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Mahrotra G. et al., Int J Dent Health Sci 2014; 1(2): 161-169 PULSE OXIMETRY patient may be recovered in the dental operatory or a separate recovery area. Pulse oximetry has revolutionized modern The sedation dental nurse monitors the monitoring procedures. It is a non- patient during this period. The dentist is invasive method of measuring arterial responsible to assess if the patient is fit oxygen saturation using a sensor probe, for discharge and ‘should only be allowed placed on the patient’s finger or ear-lobe, to leave when they have returned to a which has a red light source to detect the normal level of responsiveness and relative difference in the absorption of orientation for age and mental status’ light between saturated and desaturated hemoglobin during arterial pulsation. Once the patient is fit for discharge the Adequate oxygenation of the tissues medical observations should be recorded occurs above 95%, whereas oxygen for a final time and if these are saturations lower than this are considered satisfactory then the cannula can be being hypoxaemic. Under normal removed. Care must be taken with this as circumstances, a child’s oxygen saturation although not sharp it has been intimately (SaO2) is 97–100%. The probe is sensitive in contact with the patient’s blood. The to patient movement, relative nurse will often escort the patient back to hypothermia, ambient light and abnormal the surgery or recovery room and haemoglobinaemias, which means that reinforce postoperative instructions both false readings can occur. Indeed, the role verbally and in writing. At this stage the of carbon dioxide monitoring patient and the escort are free to leave. (capnography), as an adjunct to pulse [16] oximetry and alert clinical observation, is under increasing scrutiny. [15]

Recovery and Discharge:

Once dental treatment is complete, the patient enters the recovery phase. The CRITERIA FOR DISCHARGE Criteria Fit for Discharge Unfit for Discharge Speech Comprehensible Slurred, unintelligible Response to questioning Rational Nonsensical Orientation Aware of surroundings Patient unaware of where they are or why they are Ability to walk Stands and able to walk Unsteady on feet and Unaided require support to walk [16]

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Mahrotra G. et al., Int J Dent Health Sci 2014; 1(2): 161-169

CONCLUSION: administration of nitrous oxide/oxygen. Nitrous oxide offers patients the A number of pharmacological agents and possibility of receiving dental care with a techniques are used in dentistry to reduced level of fear and anxiety and achieve conscious sedation, enteral reduced pain. Demand for nitrous sedation, and anesthesia. The most oxide/oxygen sedation continues to commonly used conscious sedation increase. It has withstood the test of time; technique in the dental office is the 168

Mahrotra G. et al., Int J Dent Health Sci 2014; 1(2): 161-169 reduces barriers to care for fearful, phobic, and special needs patients; is safe and efficacious; and aids the provision of care by clinicians. REFERENCES:

1. Kantovitz Kamila R. Sedative effect of 9. Jevtovic-Todorovic V, Todorovic SM, oral diazepam and chloral hydrate in Mennerick S, Powell S, Dikranian K, the dental treatment of children, J Benshoff N et al. Nitrous oxide Indian Soc Pedod Prev Dent- June (laughing gas) in an NMDA antagonist 2007. neuroprotectant and neurotoxin. Nat 2. Royal College of Dental Surgeons of Med 1998; 4:460-463. Ontario (2009), Use of Sedation and 10. Conscious sedation. Part one: review General Anesthesia in Dental Practice. of indications and techniques. Dental 3. Joseph Shapira et al Comparison of Nursing February 2011 Vol 7 No 2 Oral Midazolam with and Without 11. M. T. HOSEY Managing anxious Hydroxyzine in the Sedation of children: the use of conscious sedation Paediatric Dental Patients, Paediatric in paediatric dentistry International Dentistry – 26:6, 2004 Journal of Paediatric Dentistry 2002; 4. Conscious Sedation for anxious 12: 359–372 children, Dental Nursing 2009 Vol 5 No 12. Abimbola 0 Adewumi, Flavio M 9. Soares, Enrique Bimstein. 5. Al- Zahrani AM, Wyne AH, Sheta SA, Preoperatíve Fasting Times for Dental Comparison of oral midazolam with a Sedations in Pédiatrie Dentistry. The combination of oral midazolam and Journal of Pédiatrie Dental Care - Vol. nitrous-oxide oxygen inhalation in the 15, No 1, 2010. effectiveness of dental sedation for 13. Morris S. Clark, Ann L. Brunick. young children, J Indian Soc Pedod Handbook of Nitrous Oxide and Prevent Dent, Jan-Mar 2009, Issue 1/ Oxygen Sedation, 3rd Edition. Vol 27. 14. GUIDELINES for the Use of Sedation 6. A.-L. Hallonsten, B. Jensen, M. Raadal, and General Anesthesia by Dentists As J. Veerkamp, M.T. Hosey, S. Poulsen, adopted by the October 2007 ADA EAPD Guidelines on Sedation in House of Delegates Blackwell Science, Paediatric Dentistry 2002. Ltd. 7. N.M. Girdler, C.M. Hill, K.E. Wilson, 15. UK National Clinical Guidelines in Clinical Sedation in Dentistry- 2009. Paediatric Dentistry. International Journal of Paediatric Dentistry 2002; 8. Dzolijic R. Nitrous oxide: a study of 12: 359–372 neurons. Academic Medical Center, 16. Conscious sedation. Part three: the University of Amsterdam, 1996. patient care pathway Dental Nursing April 2011 Vol 7 No 4

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