Dental Theraputic & Med Emergencies- Ch 37/TEST/COMPLETE

Anesthesia is the term

used for temporary loss of feeling or sensation

Anesthetics are the drugs

that produce the temporary loss of feeling or sensation

Methods of Pain Control

Topical anesthesia

Local anesthesia

Inhalation sedation

Antianxiety agents

Intravenous (IV) sedation

General anesthesia

Mind-body medicine

Topical Anesthesia

Provides a temporary numbing effect on nerve endings located on the surface of the oral mucosa

Supplied as:

• Ointments

• Liquids

• Sprays

• Patches

Local Anesthesia

First discovered in the mid-1800s and has greatly reduced pain during dental care

Local anesthesia is the agent most frequently used for pain control in dentistry

• Local anesthesia provides a safe, effective, and dependable method of anesthesia of suitable duration for virtually all forms of dental treatment

Characteristics of Local Anesthetics

Nonirritating to the tissues in the area of the injection

Associated with minimal toxicity

Rapid onset

Able to provide profound anesthesia

Sufficient duration of action

Completely reversible

Sterile or capable of being sterilized by heat without deterioration

Method of Action

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

Chemical Composition of Anesthetics

Two chemical groups

• Ester-type anesthetic solutions: Used primarily as topical anesthetics

• Amide local anesthetics: Metabolized by the liver

Each cartridge contains:

• Local anesthetic drug

• Sodium chloride

• Distilled water

Time Span of Anesthetics

Approximate time from induction to completion of the reversal process

• Short-acting: 30 minutes

• Intermediate: 60 minutes

• Long-acting: 90 minutes

Vasoconstrictors in Anesthetics

Indications for use

• Prolong the duration of an anesthetic agent by decreasing the blood flow in the immediate area of the injection

• Decrease bleeding in the area during surgical procedures

Types

• Epinephrine

• Levonordefrin

• Neo-Cobefrin

Ratio of Anesthetic Solution to Vasoconstrictor

1:20,000

1:50,000

1:100,000

1:200,000

Contraindications to Vasoconstrictors

Unstable angina

Recent myocardial infarction

Recent coronary artery bypass surgery

Untreated or uncontrolled severe hypertension

Untreated or uncontrolled congestive heart failure

Injection Techniques

The location and innervation of the tooth or teeth to be anesthetized will determine where topical anesthetic is placed, and the type of injection given

• Maxillary anesthesia

• Palatal anesthesia

• Mandibular anesthesia

• Periodontal ligament injection

Maxillary Anesthesia

Local infiltration is completed by injecting into a small, isolated area

Field block refers to the injection of anesthetic near a larger terminal nerve branch

Nerve block occurs when local anesthetic is deposited close to a main nerve trunk

Palatal Anesthesia

Local anesthesia in the palatal area may be necessary for procedures that involve the soft tissues of the palate

• Anterior (or greater) palatine nerve block

• Nasopalatine nerve block

Mandibular Anesthesia

Block anesthesia is frequently required for most mandibular teeth

Solution is injected near a major nerve, and the entire area served by that nerve branch is numbed

• Inferior alveolar nerve block (mandibular nerve block)

• Buccal nerve block

• Incisive nerve block

Periodontal Ligament Injection

Injection of the anesthetic solution under pressure directly into the periodontal ligament and surrounding tissues

Periodontal ligament injection is generally an adjunct (addition) to conventional techniques

Local Anesthesia Setup

Anesthetic syringe

Anesthetic cartridges

• Color-coding of local anesthetic cartridges

• Guidelines for handling anesthetic cartridges

Disposable needle

Guidelines for Handling Anesthetic Cartridges

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

Disposable Needle

Sterile needle used for injection is protected by a two-part plastic covering

Cartridge end (shorter end)

Needle hub

Injection end (protected by needle guard)

Lumen (hollow center of needle)

Gauge (thickness/size of needle)

Complications and Precautions

Injection into a blood vessel

Infected areas

Toxic reactions

• Localized reactions

• Systemic reactions

Temporary numbness

Paresthesia

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 method of anesthesia

• No risk of cross-contamination

• Reduced fear and anxiety in patients

• Patient control over own comfort level

Inhalation Sedation

Nitrous oxide/oxygen (N2O/O2)

• Combination of gases inhaled to help eliminate fear and to aid relaxation

History

• Use dates back to 1844

• Dr. Horace Wells was first to use on patients

Effects

• Nonaddictive

• Onset is easy, side effects are minimal, and recovery is rapid

• Produces stage I anesthesia

• Dulls the perception of pain

Advantages of N2O Use

Administration is simple and easily managed

The services of an anesthetist or other special personnel are not required

Excellent safety record

Side effects are minimal

The patient is awake

Recovery is rapid

Can be used with patients of all ages

Disadvantages of N2O/O2 Use

Some patients may experience nausea or vertigo

Patients who have behavioral problems may react in a negative way and act out those behavior issues

Medical Considerations to N2O Use

Pregnancy: First trimester

Nasal obstruction: Problems inhaling through the nose

Emphysema: Increased O2

Multiple sclerosis: Breathing difficulties

Emotional instability: Altered perception of reality

Chemical Makeup of Nitrous Oxide

Dinitrogen monoxide is a tasteless, sweet-smelling, colorless gas that is compressed into a blue cylinder

• The cylinder stores the liquid/gas combination in equilibrium at 650 lb to 900 lb per square inch

• Only the gas is delivered to the patient

Effects of Nitrous Oxide

Toxic substance if used improperly

Safest maximum allowable amount in the dental environment is 50 parts per million

Never administered unnecessarily or used for recreational purposes

• Could lead to abuse

Inhalation Sedation Equipment

Cylinders

• Gases are dispensed from steel cylinders, which are colored green for O2 and blue for N2O

N2O machines are portable or part of the dental unit

• Control valves control the flow of each gas

• A flow meter indicates the rate of flow of the gases

• The two gases are combined in a reservoir bag, which the patient draws on for breathing

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

Patient Assessment and Monitoring

Always review the patient’s medical history BEFORE administering N2O/O2 analgesia

• The sedative effects of N2O/O2 may enhance the effects of medications directly or indirectly

Obtain vital signs of blood pressure, pulse, and respiration before, during, and after administration

• Preoperative readings provide a baseline

• Postoperative readings are used to confirm the patient’s recovery or to identify adverse responses

Patient Education for Inhalation Sedation

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

Administration

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 N2O/O2 analgesia should end with the administration of 100% O2 for 3 to 5 minutes

Obtain postoperative vital signs and compare them with the preoperative recordings

Safety Work Practices for the Clinical Team

Used only for patient treatment

• Never administered for recreational purposes

Reducing N2O 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 N2O

Scavenger System

Essential for protection from the occupational risks of N2O

• Members of the dental team use a scavenger system to reduce the amount of N2O that escapes into the atmosphere of the dental suite, which is then inhaled

• Use of a scavenger system is recommended to reduce the N2O released into the treatment room

Antianxiety Agents

Sedatives are the drug of choice for physicians and dentists seeking to relieve anxiety in their patients

Criteria for use

• A patient is very nervous about a procedure

• A procedure is long or difficult

• The patient is mentally challenged

• The patient is a very young child requiring extensive treatment

Commonly Prescribed Sedatives

Secobarbital sodium (Seconal)

Chlordiazepoxide hydrochloride (Librium)

Diazepam (Valium)

Chloral hydrate (Noctec)

• For children

Intravenous (IV) Sedation

Antianxiety drugs administered IV throughout a procedure at a slower pace, providing a deeper stage I analgesia

Patient Assessment Before IV Sedation

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

IV Sedation

Patient monitoring

Physiologic measurements are recorded every 15 minutes

• Level of consciousness

• Respiratory function

• Oximetry

• Blood pressure

• Heart rate

• Cardiac rhythm

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

Pharmacologic makeup

• Combination of gases

• N2O/O2

• Halothane or enflurane mixture

• IV agents such as thiopental sodium and methohexital sodium

Four Stages of Anesthesia

Stage I: Analgesia

• At this stage the patient is relaxed and fully conscious

• Patient is able to keep mouth open without assistance and is capable of following directions

• Patient has a sense of euphoria and a reduction in pain

• Vital signs are normal

• Patient can move into different levels of analgesia

Stage II: Excitement

• At this stage the patient is less aware of his or her immediate surroundings

• Patient starts to become unconscious

• Patient may become excited and unmanageable

• Nausea and vomiting may occur

• This is an undesirable stage

Stage III: General anesthesia

• This stage begins when the patient becomes calm after stage II

• Patient feels no pain or sensation

• Patient will become unconscious

• This stage can be met only under the guidance of an anesthesiologist in a controlled environment such as a hospital

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

Patient Preparation

Preoperative physical examination

Laboratory tests

Signature of patient or legal guardian on a consent form

Patient Education

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

Patient Recovery

Once the procedure is completed, the patient is monitored closely until normal reflexes return

The patient should not be left alone while regaining consciousness

Mind-Body Medicine

Methods of reducing anxiety and pain through different nonpharmacologic techniques

Some common techniques include:

• Distraction (e.g., listening to music, watching iPad)

• Relaxation techniques

* Guided techniques

* Deep breathing

* Biofeedback

* Hypnosis

* Acupuncture

Documentation of Anesthesia and Pain Control

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

Analgesia

to be pain free without being unconsious

anesthetic

temporary loss of sensation or awareness with the use of drugs

anesthetic

A drug used to induce anesthesia, resulting in a temporary loss of sensation or feeling

aspiration

to draw back or draw within

diffuse

to spread out over a large area, to become less concentrated

duration

the length of time an anesthetic start to show signs of numbness to complete feeling

gauge

standard thickness, size, or measurement of something such as the thickness of an injection needle

induction

time from injection to effective anesthetic

innervation

the process by which nerves supply sensation or control to a specific area of the body.

lumen

the hollow center of the injection needle

oximetry

measurement of oxygen concentration in the blood

paresthesia

the loss of feeling

permeate

to spread/flow throughout

porous

describes an object with minute openings that allow the passage of gas or fluid

sedation

the process of calming or inducing sleepiness in a patient, often through medication.

systemic toxicity

a harmful effect affecting the entire body resulting from the absorption of toxic substances into the bloodstream.

tidal volume

amount of air inhaled and exhaled with each breath.

titrate

to determine the effective dosage of analgesic by increasing the dosage until the desired effect is achieved

vasoconstrictor

type of drug that constricts (narrows) blood vessels; used to prolong anesthetic action