Anesthesia and Pain Control Chapter 37 Copyright © 2005 by 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 © 2005 by Elsevier Inc. All rights reserved.

Methods of Pain Control Anesthetic Agents Inhalation Sedation Antianxiety Agents Intravenous Sedation General Anesthesia Copyright © 2005 by 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 © 2005 by Elsevier Inc. All rights reserved.

Fig. 37-1 Topical anesthetic (Courtesy Premier Dental Products.) Copyright © 2005 by Elsevier Inc. All rights reserved.

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 Copyright © 2005 by Elsevier Inc. All rights reserved.

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. Copyright © 2005 by Elsevier Inc. All rights reserved.

Duration Length of time from induction until the reversal process is complete. Short-acting Local anesthetic agent lasting 60-180 minutes Intermediate-acting Local anesthetic agent lasting 120-240 minutes Long-acting Local anesthetic agent lasting 240-540 minutes Copyright © 2005 by Elsevier Inc. All rights reserved.

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 Copyright © 2005 by Elsevier Inc. All rights reserved.

Ratio of Anesthetic Solution to Vasoconstrictor 1:20,000 1:50,000 1:100,000 1:200,000 Copyright © 2005 by Elsevier Inc. All rights reserved.

Contraindications for Vasoconstrictors Unstable angina. Recent myocardial infarction. Recent coronary artery bypass surgery. Untreated or uncontrolled severe hypertension. Untreated or uncontrolled congestive heart failure. Copyright © 2005 by 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 © 2005 by Elsevier Inc. All rights reserved.

Fig. 37-4 Maxillary and Mandibular Injection Sites (From Malamed SF: Handbook of Local Anesthesia, ed 5, St. Louis, 2004, Mosby.) Copyright © 2005 by Elsevier Inc. All rights reserved.

Fig. 37-6 Local Anesthesia Setup Copyright © 2005 by Elsevier Inc. All rights reserved.

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 Copyright © 2005 by Elsevier Inc. All rights reserved.

Fig. 37-8 Color-Coding of Local Anesthetic Cartridges (From Malamed SF: Handbook of local anesthesia, ed 5, St. Louis, 2004, Mosby.) Copyright © 2005 by 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 © 2005 by Elsevier Inc. All rights reserved.

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 Copyright © 2005 by Elsevier Inc. All rights reserved.

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 Copyright © 2005 by Elsevier Inc. All rights reserved.

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 Copyright © 2005 by Elsevier Inc. All rights reserved.

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 Copyright © 2005 by Elsevier Inc. All rights reserved.

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. Copyright © 2005 by 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 N²O. Copyright © 2005 by Elsevier Inc. All rights reserved.

Fig. 37-10 Portable Nitrous Oxide System Unit Copyright © 2005 by Elsevier Inc. All rights reserved.

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. Copyright © 2005 by Elsevier Inc. All rights reserved.

Fig. 37-13 Scavenger system Copyright © 2005 by Elsevier Inc. All rights reserved.

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. Copyright © 2005 by 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. 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. Copyright © 2005 by Elsevier Inc. All rights reserved.

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. Copyright © 2005 by Elsevier Inc. All rights reserved.

Commonly Prescribed Sedatives Secobarbital sodium (Seconal) Chlordiazepoxide HCl (Librium) Diazepam (Valium) Chloral hydrate (Noctec): For children Copyright © 2005 by Elsevier Inc. All rights reserved.

Intravenous Sedation Antianxiety drugs administered intravenously throughout a procedure at a slower pace, providing a deeper stage I analgesia. Copyright © 2005 by Elsevier Inc. All rights reserved.

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. Copyright © 2005 by Elsevier Inc. All rights reserved.

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 Copyright © 2005 by 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. This controlled state loss of consciousness, produces stage III general anesthesia. Copyright © 2005 by Elsevier Inc. All rights reserved.

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 Copyright © 2005 by Elsevier Inc. All rights reserved.

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. Copyright © 2005 by Elsevier Inc. All rights reserved.

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 Copyright © 2005 by Elsevier Inc. All rights reserved.

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 Copyright © 2005 by Elsevier Inc. All rights reserved.

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 Copyright © 2005 by Elsevier Inc. All rights reserved.

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. Copyright © 2005 by Elsevier Inc. All rights reserved.

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. Copyright © 2005 by Elsevier Inc. All rights reserved.