Anesthesia and Pain Control Chapter 37 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Fig Topical anesthetic. (Courtesy of Premier Dental Products.) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Chapter 37 Lesson 37.1 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Learning Objectives  Pronounce, define, and spell the Key Terms.  Discuss the importance of pain control in dentistry.  Describe the composition and application of topical anesthetics.  Demonstrate the placement of a topical anesthetic agent. (Cont’d) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Learning Objectives (Cont’d)  Discuss the composition and application of local anesthetic agents.  Demonstrate the preparation and management of the setup of a local anesthetic.  Assist during the administration of local anesthesia. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Anxiety and Pain Control A technique of various psychological, physical, and chemical approaches to prevent and treat preoperative, operative, and postoperative anxiety and pain Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Methods of Pain Control  Anesthetic agents  Inhalation sedation  Antianxiety agents  Intravenous (IV) sedation  General anesthesia Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Topical Anesthesia  Provides a temporary numbing effect on nerve endings located on the surface of the oral mucosa  Supplied as:  Ointments  Liquids  Sprays Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Local Anesthesia  The agent most frequently used for pain control in dentistry  Characteristics/advantages  Is nonirritating to the tissues in the area of the injection  Is miminally toxic  Rapid in onset  Delivers profound anesthesia  Duration of action is sufficient  Sterile  Completely reversible Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Mechanism 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Duration  Time from induction to completion of the reversal process  Short-acting  Local anesthetic agent lasting 60 to 180 minutes  Intermediate  Local anesthetic agent lasting 120 to 240 minutes  Long-acting  Local anesthetic agent lasting 240 to 540 minutes Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Vasoconstrictors  Indications for use  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  Neo-Cobefrin Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Ratio of Anesthetic Solution to Vasoconstrictor  1:20,000  1:50,000  1:100,000  1:200,000 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Contraindications to the Use of Vasoconstrictors  Unstable angina  Recent myocardial infarction  Recent coronary artery bypass surgery  Untreated or uncontrolled severe hypertension  Untreated or uncontrolled congestive heart failure Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

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 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Fig Maxillary injections. A, Local infiltration. B, Field block. C, Nerve block. (From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Anesthetic Cartridge  Precautions  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.  Never save a cartridge for reuse. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Fig Color-coding of local anesthetic cartridges. (From Malamed SF: Handbook of local anesthesia, ed 5, St Louis, 2004, Mosby.) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Local Anesthetic Cautions  Injection into a blood vessel  Infected area  Localized toxic reaction  Systemic toxic reaction  Temporary numbness  Paresthesia Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Electronic Anesthesia  A noninvasive method to block pain electronically with the use of a low-level 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  No risk of cross-contamination  Reduced fear and anxiety  Patient control over comfort level Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Chapter 37 Lesson 37.2 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Learning Objectives  Describe nitrous oxide/oxygen sedation and its use in dentistry.  Discuss the importance of reducing the dental team’s exposure to nitrous oxide.  Assist in the administration and monitoring of nitrous oxide/oxygen sedation. (Cont’d) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Learning Objectives (Cont’d)  Discuss IV sedation and its use in dentistry.  Discuss general anesthesia and its use in dentistry. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Inhalation Sedation  Nitrous oxide/oxygen (N²O/O²) is a combination of gases inhaled by the to help eliminate fear and to aid relaxation.  History  The use of nitrous oxide dates back to  Dr. Horace Wells was the first to use nitrous oxide on patients.  Effects  N²O/O² is nonaddictive.  Onset is easy, side effects are minimal, and recovery is rapid.  N²O/O² produces stage I anesthesia.  N²O/O² dulls the perception of pain. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Advantage of Using N ² O/O ²  Administration is simple and easily managed.  The services of an anesthetist or other special personnel are not required.  N ² O/O ² has an excellent safety record.  Side effects are minimal.  The patient is awake.  Recovery is rapid.  N ² O/O ² can be used with patients of all ages. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Contraindications to the Use of N ² O/O ²  Pregnancy: first trimester  Nasal obstruction: problems inhaling through the nose  Emphysema: increased O ²  Multiple sclerosis: breathing difficulties  Emotional stability: altered perception of reality Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Inhalation Sedation Equipment  Cylinders: Gases are dispensed from steel cylinders, which are colored green for O ² and blue for N ² O.  N ² O machines are portable or part of the dental unit.  Control valves control the flow of each gas.  A flowmeter indicates the rate of flow of the gases.  The two gases are combined in a reservoir bag, which the patient draws on for breathing. (Cont’d) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

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 N ² O. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Fig Nitrous Oxide gas lines are color-coded. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Exposure to Nitrous Oxide  Used only for patient treatment  Never administered for recreational purposes  How to reduce N ² O hazards to dental personnel  Use a scavenger system.  Use a patient mask that fits well.  Discourage the patient from talking.  Vent gas outside the building.  Routinely inspect equipment and hoses for leaks.  Use a monitoring-badge system to detect N ² O. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Fig Scavenger system attached to mask and evacuation unit to redirect unused nitrous oxide gas. (From Clark M and Brunick A: Handbook of nitrous oxide and oxygen sedation, ed 3, St Louis, 2008, Mosby.) (Courtesy of Accutron.) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Patient Preparation for Inhalation Sedation  Review the patient’s health history.  Obtain baseline 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. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

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.  The patient should refrain from talking or mouth-breathing.  The N ² O/O ² analgesia should end with the administration of 100% O ² for 3 to 5 minutes.  Obtain postoperative vital signs and compare them with the preoperative recordings. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Antianxiety Agents  Sedatives are the drug of choice for physicians and dentists seeking to relieve anxiety in their patients.  Criteria for use  A patients is very nervous about a procedure.  A procedures is long or difficult.  The patient is mentally challenged.  The patient is a very young child requiring extensive treatment. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Commonly Prescribed Sedatives  Secobarbital sodium (Seconal)  Chlordiazepoxide hydrochloride (Librium)  Diazepam (Valium)  Chloral hydrate (Noctec): for children Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

IV Sedation Antianxiety drugs administered IV throughout a procedure at a slower pace, providing a deeper stage I analgesia (Cont’d) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

IV Sedation (Cont’d)  Patient assessment  A health history is taken, a physical examination performed, and signed consent obtained.  Baseline vital signs are taken and recorded.  Oximetry and electrocardiography are performed and recorded.  The patient’s weight is taken and recorded for the determination of dosage. (Cont’d) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

IV Sedation (Cont’d)  Patient monitoring  Physiologic measurements are recorded every 15 minutes:  Level of consciousness  Respiratory function  Oximetry  Blood pressure  Heart rate  Cardiac rhythm Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

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—that produces stage III general anesthesia. (Cont’d) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

General Anesthesia (Cont’d)  Pharmacologic makeup  Combination of gases  N ² O/O ²  Halothane or enflurane mixture  IV agents such as thiopental sodium and methohexital sodium Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Four Stages of Anesthesia  Stage I: analgesia  At this stage the patient is relaxed and fully conscious.  The patient is able to keep his or her mouth open without assistance and is capable of following directions.  The patient has a sense of euphoria and a reduction in pain.  Vital signs are normal.  The patient can move into different levels of analgesia. (Cont’d) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Four Stages of Anesthesia (Cont’d)  Stage II: excitement  At this stage the patient is less aware of his or her immediate surroundings.  The patient starts to become unconscious.  The patient may become excited and unmanageable.  Nausea and vomiting may occur.  This is an undesirable stage. (Cont’d) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Four Stages of Anesthesia (Cont’d)  Stage III: general anesthesia  This stage of anesthesia 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. (Cont’d) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Four Stages of Anesthesia (Cont’d)  Stage IV: respiratory failure or cardiac arrest  At this stage the lungs and heart slow down or stop functioning.  If this stage is not reversed quickly, the patient will die. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

General Anesthesia (Cont’d)  Patient preparation  Preoperative physical examination  Laboratory tests  Signature of patient or legal guardian on a consent form  Preoperative instructions  The dentist will review the procedure, as well as the risks.  The patient must not have anything to drink or eat 8 to 12 hours before undergoing general anesthesia. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Recordkeeping for Sedation Methods  Always document the following measures and observations:  Review of the patient’s medical history  Preoperative and postoperative vital signs  Patient’s tidal volume if inhalation sedation is being used  Times at which anesthesia began and ended  Peak concentration administered  Postoperative time (in minutes) required for patient recovery  Adverse events and patient complaints Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.