1. Anesthesia and Pain Control
Chapter 37
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2. Anxiety and Pain Control
A technique of various psychological, physical, and chemical approaches to prevent and treat preoperative, operative, and postoperative anxiety and pain.
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3. Methods of Pain Control
Anesthetic Agents
Inhalation Sedation
Antianxiety Agents
Intravenous Sedation
General Anesthesia
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4. Topical Anesthesia
Provides a temporary numbing effect on nerve endings located on the surface of the oral mucosa.
Supplied As
Ointments
Liquids
Sprays
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5. Fig. 37-1 Topical anesthetic (Courtesy Premier Dental Products.)
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6. Local Anesthesia
Agent most frequently used for pain control in dentistry.
Characteristics
Be nonirritating to the tissues in the area of the injection
Produce minimal toxicity
Be of rapid onset
Provide profound anesthesia
Be of sufficient duration
Be sterile
Be completely reversible
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7. Method of Action
Local anesthesia temporarily blocks the normal generation and conduction action of the nerve impulses.
Local anesthesia is obtained by injecting the anesthetic agent near the nerve in the area intended for dental treatment.
Induction time is the length of time from the injection of the anesthetic solution to complete and effective conduction blockage.
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8. Duration
Length of time from induction until the reversal process is complete.
Short-acting
Local anesthetic agent lasting minutes
Intermediate-acting
Local anesthetic agent lasting minutes
Long-acting
Local anesthetic agent lasting minutes
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9. Vasoconstrictor Criteria for Use Types
Prolongs the duration of an anesthetic agent by decreasing the blood flow in the immediate area of the injection.
Decreases bleeding in the area during surgical procedures.
Types
Epinephrine
Levonordefrin
NeoCobefrin
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10. Ratio of Anesthetic Solution to Vasoconstrictor
1:20,000
1:50,000
1:100,000
1:200,000
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11. Contraindications for Vasoconstrictors
Unstable angina.
Recent myocardial infarction.
Recent coronary artery bypass surgery.
Untreated or uncontrolled severe hypertension.
Untreated or uncontrolled congestive heart failure.
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12. Injection Techniques
Infiltration is achieved by injecting the solution directly into the tissue at the site of the dental procedure.
Most frequently used to anesthetize the maxillary teeth.
Used as a secondary injection to block gingival tissues surrounding the mandibular teeth.
Block Anesthesia is achieved by injecting near a major nerve, with the entire area served by that nerve being numbed.
Type of injection required for most mandibular teeth.
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13. Fig Maxillary and Mandibular Injection Sites (From Malamed SF: Handbook of Local Anesthesia, ed 5, St. Louis, 2004, Mosby.)
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14. Fig. 37-6 Local Anesthesia Setup
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15. Anesthetic Cartridge Care and Caution of Use
Cartridges should be stored at room temperature and protected from direct sunlight
Never use a cartridge that has been frozen
Do not use a cartridge if it is cracked, chipped, or damaged in any way
Never use a solution that is discolored or cloudy or has passed the expiration date
Do not leave the syringe preloaded with the needle attached for an extended period of time
Never save a cartridge for reuse
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16. Fig Color-Coding of Local Anesthetic Cartridges (From Malamed SF: Handbook of local anesthesia, ed 5, St. Louis, 2004, Mosby.)
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17. Local Anesthetic Cautions
Injection into a blood vessel
Infected area
Localized toxic reaction
Systemic toxic reaction
Temporary numbness
Paresthesia
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18. Electronic Anesthesia
A noninvasive method to block pain electronically by using a low current of electricity through contact pads that target a specific electronic waveform directly to the nerve bundle at the root of the tooth.
Benefits to the Patient
No needles
No postoperative numbness or swelling
Chemical-free method of anesthesia
No risk of cross-contamination
Reduces fear and anxiety
Patients have control over their own comfort level
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19. Inhalation Sedation
Nitrous oxide/oxygen (N²O/O²) is a combination of gases the patient inhales to help eliminate fear and to help relax the patient.
History
Dates back to 1844
Dr. Horace Wells first used on his patients
Effects
Nonaddictive
Easy onset, minimal side effects, rapid recovery
Produces stage I anesthesia
Dulls the perception of pain
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20. Advantage of Using N²O/O²
Administration is simple and easily managed
Services of anesthetist or other special personnel not necessary
Excellent safety record
Minimal side effects
Patient awake
Recovery rapid
Used with all age of patients
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21. Contraindications of Using N²O/O²
Pregnancy: First trimester
Nasal Obstruction: Problems inhaling through the nose
Emphysema: Increased O²
Multiple Sclerosis: Breathing difficulties
Emotional Stability: Altered perception of reality
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22. Inhalation Sedation Equipment
Cylinders: Gases are dispensed from steel cylinders, which are colored green for O² and blue for N²O.
N²O machines: Portable or part of the dental unit.
Control valves: Control the flow of each gas.
Flowmeter: Indicates the rate of flow of the gases.
Reservoir bag: The two gases are combined in this bag and the patient draws on it for breathing.
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23. Inhalation Sedation Equipment-cont’d
Gas hose
Carries the gases from the reservoir bag to the mask or nosepiece.
Masks: Supplied in sizes for adults and children
The nosepiece through which the patient breathes the gases.
Scavenger system
Protection from the occupational risks of N²O.
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24. Fig. 37-10 Portable Nitrous Oxide System Unit
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25. Exposure to Nitrous Oxide
Used only for patient treatment.
Never administered for recreational purposes.
How to reduce N²O hazards to dental personnel
Use a scavenger system.
Use a patient mask that fits well.
Discourage patients from talking.
Vent gas outside the building.
Routinely inspect equipment and hoses for leaks.
Use an N²O monitoring badge system.
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26. Fig Scavenger system
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27. Patient Preparation for Inhalation Sedation
Review health history.
Obtain base-line vital signs.
Describe the procedure of administering the gases.
Describe the use of the mask and the importance of nasal breathing.
Describe the sensations that the patient will experience.
Reassure the patient.
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28. Assisting in the Administration of Inhalation Sedation
Start with pure oxygen while establishing the patient’s tidal volume.
Slowly titrate the nitrous oxide until the desired results are achieved.
Patients should refrain from talking or mouth breathing.
The N²O/O² analgesia should end with the administration of 100% O² for 3 to 5 minutes.
Obtain postoperative vital signs and compare them to the preoperative recordings.
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29. Antianxiety Agents
Sedatives are the drug of choice by physicians and dentists for relief of anxiety.
Criteria for Use
Patients are very nervous about a procedure.
Procedures are long or difficult.
Mentally challenged patients.
Very young children requiring extensive treatment.
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30. Commonly Prescribed Sedatives
Secobarbital sodium (Seconal)
Chlordiazepoxide HCl (Librium)
Diazepam (Valium)
Chloral hydrate (Noctec): For children
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31. Intravenous Sedation
Antianxiety drugs administered intravenously throughout a procedure at a slower pace, providing a deeper stage I analgesia.
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32. Intravenous Sedation-cont’d
Patient Assessment
A health history, physical examination, and signed consent are performed.
Baseline vital signs are taken and recorded.
Oximetry and electrocardiogram are completed and recorded.
Weight taken and recorded for dose determination.
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33. Intravenous Sedation-cont’d
Patient Monitoring
Physiologic measurements taken and recorded every 15 minutes.
Level of consciousness
Respiratory function
Oximetry
Blood pressure
Heart rate
Cardiac rhythm
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34. General Anesthesia
A controlled state of unconsciousness with a loss of protective reflexes, including the ability to maintain an airway independently and to respond appropriately to physical stimulation or verbal command.
This controlled state loss of consciousness, produces stage III general anesthesia.
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35. General Anesthesia-cont’d
Pharmacologic Make-up
Combination of gases
N²O/O²
Halothane or enflurane mixtures
Intravenous agents such as thiopental sodium and methohexital sodium
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36. Four Stages of Anesthesia
Stage I: Analgesia
The stage at which a patient is relaxed and fully conscious.
Able to keep his or her mouth open without assistance and is capable of following directions.
Have a sense of euphoria and a reduction in pain.
Vital signs are normal.
The patient can move into different levels of analgesia.
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37. Four Stages of Anesthesia-cont’d
Stage II: Excitement
The stage at which a patient is less aware of his or her immediate surroundings
Starts to become unconscious
The patient can become excited and unmanageable
Nausea and vomiting can occur
This is an undesirable stage
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38. Four Stages of Anesthesia-cont’d
Stage III: General Anesthesia
The stage of anesthesia that begins when the patient becomes calm after stage II
The patient feels no pain or sensation
The patient will become unconscious
This stage of anesthesia can be met only under the guidance of an anesthesiologist in a controlled environment such as a hospital
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39. Four Stages of Anesthesia-cont’d
Stage IV: Respiratory Failure or Cardiac Arrest
The stage at which the lungs and heart slow down or stop functioning
If this stage is not reversed quickly, the patient will die
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40. General Anesthesia-cont’d
Patient Preparation
Preoperative physical examination.
Laboratory tests.
Patient or legal guardian must sign a consent form.
Preoperative Instructions
Dentist will review the procedure, as well as the risks.
Must not have anything to drink or eat 8 to 12 hours before receiving general anesthesia.
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41. Record Keeping for Sedation Methods
Always document the following measures and observations:
Review of patient’s medical history.
Preoperative and postoperative vital signs.
Patient’s tidal volume if using inhalation sedation.
Time anesthesia began and ended.
Peak concentration administered.
Amount of postoperative time (in minutes) for patient recovery.
Adverse events or patient complaints.
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