OXIDE -OXYGEN INHALATION

Dr.zameer pasha

Sedation • The provision of adequate anxiety control is an integral part of the

practice of dentistry.

• It is of fundamental importance that the level of sedation must be such that the patient remains conscious, and is able to both understand and respond to verbal commands.

• Conscious sedation: • A minimally depressed level of consciousness, that retains patient’s ability to maintain an airway independently and respond appropriately to physical stimulation and verbal command

• Deep sedation: a controlled state of depressed consciousness, accompanied by partial loss of protective reflex, including inability to respond to verbal commands

• General anesthesia : control state of unconsciousness accompanied by complete loss of protective reflexes including inability to maintain air way independently and respond to verbal commands

• Goals for sedation to control behavior to allow procedure to be completed successfully.

• • Kids under age 5 or 6 (chronologically or developmentally) may require deep sedation

Pre- sedation assessment • A fully recorded medical history.• Blood pressure.• Weight, if recorded.• ASA status.• A dental history.• A conscious sedation and general anaesthetic history.

• Dental treatment plan.• The selected conscious sedation technique.• Any individual patient requirements.• Provision of pre- and post-operative written instructions provided

before treatment.• Written consent for conscious sedation and dental treatment.

TYPES / ROUTES OF ADMINISTRATION • Inhalation

• Nitrous oxide • Desflurane• Sevofuraine

• Oral • Diazepam • Triazolam

• Intramuscular• Ketamine • Midazolam

• Intravenous • Midazolam• propofol

• Conscious Sedation for Children• Nitrous oxide/oxygen is usually the technique of choice for conscious

sedation of pediatric dental patients • Nitrous Oxide is a very quick acting inhaled sedation medicine that

decreases discomfort and anxiety. • Sometimes called “laughing gas” • Often given at the dentists office • Nitrous Oxide is a sweet-smelling, colorless gas. • It is heavier than air or oxygen

History of N2O• 1793 - Joseph Priestly invented N2O• In 1844, Dr. Gardner Colton• Initially used as an anesthetic agent

in 1844. by Dr. Horace Wells• Roberts in 1990 and dr. kevin allen

demonstrated relative analgesia on child patient

Pharmacokinetic properties Onset• Anywhere from a few seconds up to 3-5 minutes • Crosses the blood-brain barrier rapidly Elimination • Rapid elimination • Unchanged with exhalation from the lungs • Do not hold a child close to your face while they are “waking up”

No significant metabolism by the liver or kidneys • Not stored in the tissues

Fear Reduction & N2O

• One 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.

• When 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.

Four Stages of Anesthesia • Analgesia

• patient is conscious • reflexes are intact

• Delerium • Surgical Anesthesia • Respiratory Paralysis

• In 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.

N2O Should Be Used To:• Ease fears and anxieties • Aid in the treatment of special patients • Increase tolerance for longer appointments • Raise the pain reaction threshold

N2O Should Not Be Used To:• uncontrolled behavior • Control pain by replacing local anesthesia • Replace poor techniques of behavior management

Administration of N2O • 5 - 6 liters O2 • Increase N2O gradually; watch for stages of analgesia • Maintenance about 40% -50%• Reduce N2O with long procedures • Record N2O levels in the chart • 3 - 5 minute O2 flush • Rapid induction technique

• 1. Open both tanks (O2 and N2O) • 2. Turn the On/Off switch to On • 3. Adjust the green (O2) and blue (N2O) levers to administer a 50/50

mixture of oxygen and Nitrous Never turn on the gases until the mask is sealed on the patients face! …

• Begin with a 20/80 mix of N2O and O2 and titrate to achieve desired level of sedation/anxiolysis

• Nitrous oxide may be administered to a maximum of 60% Remember the patient is not “asleep”

• Patient should appear calm and relaxed

Administration of N2O/O2

Titration is an important skill in administering nitrous oxide.

Titration is a method of administering a drug in incremental amounts until a desired endpoint is reached. If done properly, the patient does not receive more of the drug than is necessary.

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Administration of N2O/O2

Advantages of N2O titration• Only the amount of drug

required by the patient is given.

• Allows for individual biovariability

• Uncovers idiosyncratic reactions early

• Minimizes negative experiences with over sedation

Potential side effects of nitrous oxide

• Detachment / disassociation from environment• Dreaming, hallucinating, or sexual fantasizing• Out-of-body experiences• Floating and/or flying• Physical body movements may become restless, combative, sluggish• Inability to move, communicate, or keep mouth open

• Words may be slurred or repeated; incoherent sentences

Potential side effects of nitrous oxide• Humming or vibrating sounds that progressively worsen• Fits of uncontrolled laughter• Patient may experience:

• Drowsiness• Dizziness / Light headedness / spinning sensations• Diaphoresis • Nausea / vomiting• Fixed eyes• Uncomfortable body warmth• Unconsciousness

Contraindications for use of N2O/O2 sedation

• N2O rapidly replaces N2 in air filled spaces in the body causing expansion of those spaces; therefore, N2O/O2 should not be used in patients with:

• Pneumothorax• Middle ear occlusion/surgery• Recent (within 3 weeks) craniotomy/pneumoencephalography• Increased intracranial pressure• Intraocular injury/surgery (injected gas may last up to 10 weeks)• Maxillofacial injuries• Intestinal obstruction• Cystic fibrosis

Contraindications for use of N2O/O2 sedation• Current upper respiratory tract infection• Chronic obstructive pulmonary diseases• Vitamin B12 deficiency• Psychological impairment• Phobic individuals• Bleomycin therapy• Current psychotropic drug use• Current or recovering drug use/addiction• First trimester of pregnancy• Any facial injury which would prevent use of the mask

Note: Asthma is not a contraindication

Potential biohazards of N2O for health professionals

• No direct evidence suggests any causal relationship between chronic low-level exposure to N2O and potential biologic effects.

• The following preventive measures to reduce or eliminate trace gas contamination are encouraged:

• Operate a delivery system with scavenging capabilities, accurate flow meter, adequate vacuum, and a variety of mask sizes.

• Maintain a ventilation system to include vent exhaust to outside and fresh air exchange when possible.

• Maintain an adequate suction system – ensure vacuum, use appropriate size mask, discourage patient talking.

• Inspect cylinder attachments, lines, hosing, and reservoir bag for leaks.

• Calibrate flow meters every 2 years.