1. Part 6 Local Anesthetics

2. procaine普鲁卡因 lidocaine利多卡因 tetracaine 丁 卡 因

3. Local anesthetics 1. Pharmacological effects1. Pharmacological effects (1) Local anesthetic effects(1) Local anesthetic effects inhibiting Na + inward flow and the conduction of nerve fibers sensory (fine – thick)  CNS(inhibiting - excitatory)  ANS  motor nerves  muscles sensory (fine – thick)  CNS (inhibiting - excitatory)  ANS  motor nerves  muscles

4. The mechanism of local anesthetics Blocking Na + channels on the nerve fibers

5. The mechanism of local anesthetics Intracellular blockade of Na + channel

6. Local anesthetics (2) Systemic effects （ Adverse effects ）(2) Systemic effects （ Adverse effects ） Depressing CNS ： excitation - depression Cardiovascular effects ： heart depression; vasodilatation; lowering BP Cardiovascular effects ： heart depression; vasodilatation; lowering BP combined with epinephrine: reducing absorption and systemic effects combined with epinephrine: reducing absorption and systemic effects ( but contraindicated in: terminal tissues; epinephrine contraindications ) ( but contraindicated in: terminal tissues; epinephrine contraindications )

7. 2. Clinical uses2. Clinical uses (1) Surface anesthesia ( 表面麻醉 ）(1) Surface anesthesia ( 表面麻醉 ） penetration (2) Infiltration anesthesia （ 浸润麻醉 ）(2) Infiltration anesthesia （ 浸润麻醉 ） (3) Conduction anesthesia （ 传导麻醉 ）(3) Conduction anesthesia （ 传导麻醉 ） Local anesthetics

8. (4) Epidural anesthesia ( 硬脊膜外麻醉 )(4) Epidural anesthesia ( 硬脊膜外麻醉 ) Avoiding misdirection into cerebrospinal fluid (5) Subarachnoid anesthesia ( 蛛网膜下腔麻(5) Subarachnoid anesthesia ( 蛛网膜下腔麻 醉, 腰麻 ） 醉, 腰麻 ） head-up position; head-up position; hyperbaric solution; hyperbaric solution; hypotension: prevention with ephedrine hypotension: prevention with ephedrine Local anesthetics

10. 3. Adverse effects3. Adverse effects (1) Systemic effects(1) Systemic effects depression of CNS: excitation – depression – respiratory depression depression of CNS: excitation – depression – respiratory depression cardiovascular effects: hypotension; arrhythmia cardiovascular effects: hypotension; arrhythmia (2) Allergic reactions(2) Allergic reactions urticaria, bronchoconstriction; anaphylactic shock urticaria, bronchoconstriction; anaphylactic shock Local anesthetics

11. 4. Special agents4. Special agents Efffect Toxicity Pene- Uses Efffect Toxicity Pene- Uses tration tration procaine weak weak weak can not be used 普鲁卡因 (allergic) for surface skin allergic test skin allergic test lidocaine stronger lower stronger for various uses ； 利多卡因 anti-arrhythmia tetracaine stronger stronger stronger mainly for surface 丁卡因 Local anesthetics