Anesthesia and Sedation 20 Anesthesia and Sedation

Anesthetics and Sedation Reduce pain Relieve anxiety Different levels of sedation can be achieved based upon procedural need and patient response Many patients are very anxious about dental care and treatment. Sedation is one method of managing the anxiety of the patient. Anesthesia can also be used to control the pain the patient experiences. Depending on the need, various levels of sedation can be achieved from conscious sedation to deep sedation.

Conscious Sedation Causes an altered state of consciousness Patient can still communicate May experience headache, nausea, brief periods of amnesia Conscious sedation places the patient in an altered level of consciousness. The patient is still able to communicate and respond to questions. This form of sedation serves to lower levels of pain and discomfort. The patient may experience a headache, nausea, and brief periods of amnesia following conscious sedation.

IV Sedation Administered directly into the bloodstream Patient may be conscious but in a deeply relaxed state Patient has no memory of events taking place while sedated Anesthetics are administered directly into the bloodstream and remain in place throughout the procedure. The patient may remain conscious but is in a deeply relaxed state. The patient often has no recollection of the events that took place while under anesthetic. This form of sedation keeps patient’s relaxed, comfortable, and pain free.

Oral Sedation Prescription taken before appointment May make the patient calm and drowsy or calm and relaxed Oral sedation is achieved by taking a medication the night before a dental procedure. This may be prescribed for the patient who is extremely anxious about the procedure to be done. Benzodiazepine is often used and can be a sedative hypnotic, which makes the patient calm and drowsy or an anti-anxiety drug, which makes the patient calm and relaxed.

Inhalation Sedation Odorless and colorless gases Inhaled through mask Patient doesn’t remember much of procedure Inhalation sedation may be used when it is difficult to achieve IV sedation. The anesthetics are administered in a gas form by inhalation through a mask. This will cause the patient to become sleepy and serves to relieve pain. The patient often doesn’t remember much of the procedure. It is not long-lasting so the patient must be carefully monitored.

Intramuscular Sedation Injection into muscle of upper arm or thigh Not commonly used Takes 20 to 30 minutes to take effect Intramuscular sedation is injection of an anesthetic directly into the muscle of the upper arm or thigh. It is not commonly used but may be seen in pediatric practices. It takes 20 to 30 minutes for the anesthetic to take affect with this route of administration.

General Anesthesia Creates an unconscious state Must be carefully controlled Sensation and feeling is lost General anesthesia provides a deep level of sedation that creates an unconscious state. The patient’s vital signs must be closely monitored and the patient will be on a ventilator for the duration of the sedation. General anesthesia alters and depresses the patient’s central nervous system. The patient will loose all sensation and feeling.

Topical Anesthesia Numbs a particular area Used prior to local anesthetic Desensitizes the oral mucosa A topical anesthetic is often used prior to the local anesthetic. The nerve endings in the mucosa are desensitized causing numbness. This alleviates the sensation of the pinch of the needle used to inject the local anesthetic.

Local Anesthesia Produces a deadened or pain free area Sensory impulses are temporarily blocked Affects the nerve fibers carrying messages to brain Local anesthetics are used to reduce the sensation of pain, touch, and heat to a particular area. This type of anesthetic works on the nerve fibers to block sensory impulses.

Topical Anesthetics Used for the following: Subgingival scaling Root planing Seating crowns Placing matrix bands Periodontal probing Preparation for local sedation Repress gag reflex We want the patient to be cooperative, conscious, and relaxed. Topical are available in gels, ointments, liquids, or sprays. This anesthetic helps prepare the area to accept a needle without pain. Usually benzocaine or lidocaine. Can cause an allergic reaction up to 24 hours after the application. This reaction may cause swelling, redness, ulcerations, difficulty swallowing and difficulty breathing. A toxic reaction can also occur and initially the patient will become more talkative, apprehensive, and excited with an increase in pulse and blood pressure.

Placing Topical Anesthetic Determining factors for how much a patient should receive may include: Age Weight Physical condition Liver function Topical 5% to 10% anesthetic solution Local consists of 2% anesthetic solution. Patient reactions may include: Talkative Apprehensive Excited Increased pulse and blood pressure Patient becomes sleepy afterward

Local Anesthetics Used to manage pain Can be short, intermediate, or long in duration Vasoconstrictor Local anesthetics are primarily used to alleviate and control pain during a procedure. They come in liquid form and are injected into the tissues. A short-duration local will last about 30 minutes. An intermediate-duration local will last about 60 minutes. A long-duration local will last longer than 90 minutes. Local anesthetics may contain vasoconstrictors, which constrict blood vessels to reduce blood flow to the area of the injection site. Vasoconstrictors reduce the levels of anesthetics entering the blood stream thus reducing the chances of a toxic reaction and decreases blood flow at the site. Epinephrine is the most commonly used.

Possible Complications of Local Anesthetics Toxic reactions Patient becomes ill Many factors Paresthesia Numbness does not go away as expected Patient with toxic reaction possibly because of an overdose, the type used, absorption rate, or individual characteristics. Symptoms may include: Drop in blood pressure Nausea and vomiting Pallor Convulsions Muscular twitching Apprehension Temporary numbness Paresthesia could last a few days or up to eight weeks. Causes for this may include: Nerve sheath damage during injection Hemorrhage: creating pressure on nerve Contamination of anesthetic

Types of Injections Local infiltration Field block Nerve block Injection near small terminal nerve branches Field block Injection near large terminal nerve branches Nerve block Injection near main trunk nerve Local infiltration used for various dental treatments include root planning, soft tissue inclusion for biopsy, gingivectomy, and frenectomy. Field block infiltration are given near the apex of the tooth and involve one or two teeth. Usually, the patient feels numb within two to three minutes. Nerve block eliminates sensations over a larger area than infiltration or field block. Used to numb an entire region. Usually takes effect within five minutes. Local infiltration - surrounding tissue or one tooth Field blocks - one or two teeth Nerve blocks - entire quadrant

Maxillary Arch Injection Sites Infiltration (field block) Anterior superior alveolar nerve block (infraorbital nerve block) Middle superior alveolar nerve block Posterior superior alveolar nerve block Greater palatine nerve block Nasopalatine nerve block Maxillary nerve block – all injections affect separate teeth and tissues.

Anesthetic Setup Health history, cotton tip applicator tip, topical.

Aspirating Syringe Various types of syringes may be used in dental procedures; most common is the aspirating syringe. Aspirating syringe allows operator to verify that they have not penetrated a blood vessel. Harpoon of syringe is retracted; if blood appears in syringe then needle is repositioned. Parts of the Aspirating Syringe Thumb ring Finger grip/bar Syringe barrel Plunger Harpoon Threaded end of the syringe

Components of a Needle Needle length Short (1 inch) used in infiltrations and field blocks. Periodontal ligament injections. Long (1-5/8 inch) used for nerve blocks, maxillary and mandibular, reaches posterior areas, for areas that require penetration of thicker tissue. Needle Gauge Sizes... the smaller the gauge the larger the diameter of the needle. 25 gauge 27 gauge 30 gauge Needle Parts Bevel Shank Hub Syringe end

Needle Care and Handling Maximum of four penetrations Stick protection Caps and shields Proper disposal OSHA guidelines Sharps container Procedure if stick occurs OSHA Bloodborne Pathogens protocol Procedure if needle stick occurs Immediately squeeze the area of the needle stick or puncture to make it bleed. Go to a sink and wash the wound area with an antimicrobial soap. Notify the dentist and find out which patient the instrument was used on. Review the patent’s chart and medical history. Follow OSHA protocol for occupational exposure to Bloodborne Pathogens.

Anesthetic Cartridge Components Parts of the Anesthetic Cartridge Glass cartridge Rubber stopper or plunger Aluminum cap Diaphragm

Retracting Harpoon Left hand retraction of the piston rod of an aspirating anesthetic syringe.

Loading Cartridge into Syringe Technique for placing a cartridge in an aspirating syringe.

Engaging Harpoon Engage the harpoon with pressure on the finger ring (bar).

Placement of Needle into Syringe Open the cap of the needle.

Passing the Syringe After drying the inside tissue with a gauze, place topical anesthetic on injection site, and pass the syringe.

Disassembling the Syringe Retract the piston to release the harpoon from the cartridge and remove the cartridge from the syringe.

Intraosseous Anesthesia Cancellous bone injected directly Special equipment required Anesthetizes the following: Bone Soft tissue Root Teeth Single or multiple teeth Places local anesthetic directly into the cacellous bone. Lip and tongue do not become numb.

Periodontal Ligament Injection Used for pulpal anesthesia of one or two teeth in a quadrant May be an adjunct to another injection where patient is partially anesthetized Aids in diagnosing abscessed teeth This technique involves inserting the needle into the gingival sulcus along the axis of the tooth to be anesthetized.

Periodontal Ligament Injection System Developed in 1905; technique is becoming popular today again. Often used with other types of injections. Diagnosing abscessed teeth. Outcome is pulpal anesthesia. Technique Inserted into the gingival sulcus of the tooth Requires special pressure syringes

Intrapulpal Injection Delivered directly into nerve chamber Procedures Root canal therapy Severe abscess This injection may be used when there is difficulty in securing numbness in the patient by traditional methods.

Electronic Anesthesia Used with nitrous oxide provides a better effect Used in the following procedures: Placing restorations Muscle relaxation Determination of centric occlusion Used alone, electric anesthesia has had low to moderate levels of success. When used in combination with nitrous oxide the effects are improved. This type of anesthesia can be used in patients who have an adverse reaction or are allergic to local anesthetics or who are fearful of injections.

Computer-Controlled Local Anesthesia Delivery System Pain-free injections Used for all traditional infiltration and block injections The computer-controlled injection system uses a microprocessor to deliver controlled pressure and volume of anesthetics to a site. The microprocessor adjusts to the resistance of the tissues and offers a pain free injection.

Nitrous Oxide Safe, stable, non-flammable gas Relaxes and comforts the patient Some states allow dental assistants to perform this task under dentist supervision. Other states only allow assisting dentists. Nasal hoods, scavenging circuit. Asking the patient how they are feeling is key to adjusting the flow for that specific patient. First discovered by Joseph Priestly in the early 1770s. It was thought the gas would cure diseases. Horace Wells, a Connecticut dentist, was the first to use nitrous oxide as an anesthetic during dental surgery in the early 1800s.

Nitrous Oxide Contradictions Blocked nasal passage Emotional instability Drug users First trimester of pregnancy Risk of bone marrow suppression In-vitro fertilization procedures Neurological complaints