LA Intro

LA Intro

1. DEFINITION

   • Anesthesia - Insensitivity to pain, especially as artificially induced by the administration of gases or the injection of drugs before surgical operations

2. TYPES

   • Local
   • Regional
   • General

3. INDICATION

   • Topical anesthesia
     • anesthetize the skin, mucous membranes or cornea
     • absorption when the mucosa is dried
     • Comes as form of solution, ointment, cream or spray
   • Others (Eg. Iontophoresis)
     • small electric current to force molecules of the anesthesia into the tissue
     • Does not need injection
     • Can be used for child
   • Injection
     • Infiltration
       • Most common
       • injected directly into subcutaneous tissue just under the skin
       • Epinephrine can be added to decrease dosage and prolong its duration of action
     • Regional nerve block
       • Blocks the conductivity of sensory nerves
       • • injected into or adjacent to a peripheral nerve or nerve plexus

4. MECHANISM

   • Local anesthetic will bind to a receptor inside the sodium channels and antagonize it
   • closing the sodium channels
   • nerve membrane become less permeable to sodium
   • prevent depolarization and nerve activity
   • patient will not feel any pain

5. COMPONENTS

   • Local anesthetic drug
   • Vasoconstrictor drug
   • Preservative for vasoconstrictor drug
   • Sodium chloride
   • Distilled water
   • General preservatives

6. CONTRAINDICATIONS

   • Diabetics
   • Uncontrolled hypertension
   • Pregnancy (1st and 2nd trimester)

7. Commonly used LAs

   • Lidocaine
   • Mepivacaine
   • Prilocaine
   • Bupivicaine
   • Articaine