Anesthesia Overview

  • Anesthesia Definition:

    • Control of pain during surgeries/procedures using anesthetics.

    • Manages breathing, blood pressure, blood flow, and heart rate.

  • Types of Anesthesia:

    1. General Anesthesia:

    • Induces unconsciousness.

    • Combines intravenous drugs and inhaled gases.

    1. Local/Regional Anesthesia:

    • Loss of sensation in a specific area without loss of consciousness.

  • Administration Methods:

    1. Inhalation:

    • Common method; anesthetic gas enters bloodstream via alveoli.

    1. Intravenous:

    • Injected into circulation through veins.

  • Administered Agents:

    • Inhalation:

    • Nitrous oxide, Halothane, Isoflurane, etc.

    • Intravenous:

    • Pentothal sodium, Fentanyl, Propofol.

  • General Anesthesia Stages:

    1. Stage 1: Induction (loss of consciousness)

    2. Stage 2: Excitement (increased HR, BP)

    3. Stage 3: Surgical anesthesia (unresponsiveness)

    4. Stage 4: Danger (medullary depression, risk of overdose).

  • Advantages/Disadvantages of General Anesthesia:

    • Advantages:

    • Patient unconscious, controlled respiration and cardiac function.

    • Disadvantages:

    • Can depress respiratory and circulatory systems.

  • Local Anesthesia Techniques:

    • Topical: Applied directly to skin/mucous membranes (e.g., lidocaine).

    • Infiltration: Injection into tissues to block nerve signals.

    • Nerve Block: Specific nerves are targeted to interrupt pain transmission.

  • Spinal Anesthesia:

    • Injection into subarachnoid space, affecting lower body sensation.

  • Epidural Anesthesia:

    • Injection into the epidural space, commonly used for labor pain management.

  • Complications of Anesthesia:

    • Risks of respiratory distress, cardiovascular effects, or overdose.

  • Terms and Abbreviations:

    • GETA: General Endotracheal Tube Anesthesia

    • SAB: Sub-arachnoid Block

    • PNB: Peripheral Nerve Block

    • TIVA: Total Intravenous Anesthesia.