Sedation Techniques in Dentistry

Sedation Techniques

• Nitrous Oxide Sedation is a common technique for dental procedures
• Introduced by Langa in 1966, initially termed "Relative Analgesia"
• Modern terminology prefers "Inhalational Sedation"
• The technique involves administering nitrous oxide (0-70%) and oxygen
• Semi-hypnotic suggestions for relaxation are often used
• Fail-safe equipment is crucial to prevent 100% nitrous oxide exposure
• Local anesthesia is the primary pain control method
• Nitrous oxide provides supplemental analgesia for minor deficiencies

Indications for Nitrous Oxide Sedation

• Uncooperative children or apprehensive adults
• Mildly apprehensive patients
• Medically compromised patients
• Patients with gagging issues

Contraindications for Nitrous Oxide Sedation

• Extreme anxiety or nasal obstruction / habitual mouth breathing
• Upper respiratory tract infections
• Serious psychiatric disorders
• Chronic Obstructive Pulmonary Disease (COPD)
• First trimester of pregnancy

Advantages of Nitrous Oxide Sedation

• Rapid onset, allowing for quick sedation

• Pleasant, non-irritating odor for patient comfort

• Fast uptake and elimination, resulting in minimal downtime after the procedure

• Quick recovery period with minimal hangover effects

• Precise control over sedation levels using "breath-to-breath" titration

• Wide safety margin with a low risk of adverse effects

• Maintains stable vital signs throughout the procedure

• Patient continues to breathe independently

Disadvantages of Nitrous Oxide Sedation

• Specialized, expensive equipment (e.g., vaporizers) is required
• Potential occupational hazards for dental and nursing staff due to exposure
• Higher abortion rates reported in female dental assistants using nitrous oxide
• Risk to pregnant patients, particularly during the first trimester

Exposure Minimization Strategies

• Test equipment for leaks
• Vent waste gases outside
• Use scavenging nasal hoods
• Employ airsweeps (portable fans)
• Minimize conversation (avoid mouth breathing)
• Monitor air quality using infrared (IR) analyzers to maintain nitrous oxide levels below 50 ppm

Color Coding of Compressed Gases

• Oxygen (O2): Green (white - international standard)
• Nitrous Oxide (N2O): Light blue
• Nitrogen (N2): Gray bottom with an orange shoulder
• Carbon Dioxide (CO2): Gray
• Helium: Brown

Nitrous Oxide Sedation - Armamentarium

• Continuous-flow inhalation sedation unit; usually portable

• Yoke assembly

• Pressure gauge

• Low-pressure tubing

• Compressed-gas cylinders

• Full-face mask covers the nose and mouth of the patient and is suitable for emergency situations but is inconvenient for dental care

• Nasal cannula with two short plastic prongs placed in the nostrils for patient use

Before Nitrous Oxide-Oxygen Sedation

• 100% oxygen is used to begin and end the sedation
• Recommended fasting guidelines should be followed
• Patients should empty their bladder prior to treatment
• Contact lenses should be removed
• Artificial dentures should be removed

Nitrous Oxide Sedation - Sedation Procedure and Monitoring

• Patient positioning: comfortable reclined position on a dental chair

• Oxygen flow: start with 5 liters per minute using a nasal mask ensuring proper fit

• Nitrous Oxide titration: begin with 10% nitrous oxide, slowly increase, monitor for sensory disturbances (tingling, tinnitus) and adjust the concentration (aiming for 35-40% concentration) based on patient responses

• Vital Signs monitoring: regularly monitor vital signs

• Pulse Oximetry & ECG: observe oxygen saturation and heart rate stability

• Verbal Communication: maintain communication with the patient during the entire procedure

Nitrous Oxide Sedation - Post-Procedure Care and Safety

• Post-sedation protocol: administer 100% oxygen for 3-5 minutes post-procedure to prevent diffusion hypoxia
• Escort required: do not let patients leave unescorted after sedation
• Activity restrictions: avoid fine motor activities (driving, operating machinery) for 24 hours post-procedure

Sedation Techniques in Special Situations

• Specific techniques and considerations for patients with various conditions like cardiovascular ailments, asthma, and epilepsy

Cardiovascular Diseases

• Indications: angina pectoris, congestive cardiac failure, severe cardiac dysrhythmias, myocardial infarction, high blood pressure (hypertension)

• Benefits: analgesic, amnesic, sedative properties; reduced myocardial workload; oxygen-enriched gas mixture for heart support

• Intravenous sedation caution: administer slowly and in diluted concentrations to avoid sudden cardiovascular compromise

Asthma

• Stress can trigger asthma exacerbation during procedures.
• Recommended inhalational agents: Halothane and Sevoflurane (pleasant odor and bronchodilator properties)
• Avoid Isoflurane (can irritate airways)
• Intravenous agents: Propofol (minimalizes airway irritability); Ketamine (bronchodilator properties, ideal for airway hypersensitivity)
• Avoid Thiopentone (exacerbates airway irritability and has a risk of bronchospasm)

Epilepsy

• Preferred medications: Benzodiazepines (e.g., Midazolam) exhibiting antiepileptogenic properties.

• Ideal for patients with a history of epilepsy.

• Intravenous sedatives: Thiopentone or Propofol: effective and safe options.

• Avoid long-acting benzodiazepines (e.g., diazepam, lorazepam) for their delayed recovery and depression risks and typically avoided during office based procedures

• Nitrous Oxide: safe and non-epileptogenic for chronic seizure patients; safe for use provided hypoxia is avoided

Hepatic Dysfunction

• Nitrous oxide: No biotransformation; safe and effective

• Avoid Halothane (can worsen liver condition)

• Use intravenous drugs cautiously: administer in titrated doses, carefully monitor patient status as many IV medications, are metabolized in the liver.

Chronic Obstructive Pulmonary Disease (COPD)

• COPD characteristics: elevated carbon dioxide (CO2) blood levels; breathing stimulus triggered by low oxygen (O2) levels.
• Inhalational sedation risk: oxygen-enriched gas raises oxygen levels, potentially reducing natural breathing stimulus and leading to respiratory apnea
• Inhalational sedation management: cautious management to prevent respiratory complications

Clinical Indicators of Oversedation

• Excessive sedation: patient too deeply sedated or agitated

• Airway & breathing issues: obstructed airway or difficulty breathing.

• Sluggish response: patient responds slowly.

• Uncooperativeness: patient becomes uncooperative.

• Emotional reactions: laughing, crying, feeling giddy.

• Loss of coordination: uncoordinated movements.

• Incoherent speech

Postoperative Discharge Scoring Systems

• Purpose: ensuring patients are not oversedated to minimize postoperative morbidity using methods like modified Aldrete score and Post-Anesthesia Discharge Scoring System (PADDSS).

• Modified Aldrete Score: assesses recovery based on activity, respiration, circulation, consciousness, and oxygen saturation

• Post-Anesthesia Discharge Scoring System (PADDSS): evaluates vitals, ambulation, nausea and vomiting, pain, and surgical bleeding to determine readiness for discharge