C3 U2 Induction & GA

Introduction to Small Animal Anesthesia

  • Overview of the anesthesia process from induction to recovery.

  • Importance of patient preparation covered in the initial course.

  • Use of checklists to prevent critical steps from being missed, avoiding life-threatening events.

Anesthetic Protocols

  • Individualized protocols are necessary for each patient to minimize adverse effects.

  • Evaluation of physiologic abnormalities (dehydration, hypotension, anemia) helps ensure patient safety.

  • Importance of double-checking calculated doses, syringes, and labels between two personnel.

    • Triple Checks:

      • Drug name and concentration should be verified during:

        • Removal from the shelf

        • Drawing up

        • Returning to shelf

Induction and Maintenance Options

Induction Routes

  • IM Induction:

    • Not commonly used due to loss of control over anesthesia.

    • Slower onset (15-20 minutes for peak effect).

    • Common drugs: Propofol, Alfaxalone, Etomidate.

    • Longer recovery due to metabolism/redistribution.

  • IV Induction:

    • Allows for quicker unconscious state.

    • Peak effect lasts about 5 minutes; top-ups can be administered if needed.

    • Doses are titrated to effect to prevent over-sedation.

Total Intravenous Anesthesia (Teva)

  • IV Boluses:

    • Induction to effect with additional boluses every 3-5 minutes.

    • Gradual recovery after agent metabolism.

  • Constant Rate Infusion (CRI):

    • Rapid induction and short peak effect.

    • Surgical anesthesia maintained with adjustments based on patient assessment.

Inhalant Induction

  • Less common due to the availability of multimodal options.

  • Delay noted with vaporizer settings affecting onset time (around 10 minutes).

  • Recovery is gradual but relatively rapid post inhalant cessation.

Importance of Monitoring During Induction

  • Anesthetist should keep patients visible and separate from clinic chaos for effective monitoring.

  • Begin warming process to mitigate hypothermia.

  • Sedation does not typically include analgesic properties unless using dissociative agents.

  • Assess readiness for intubation through signs of unconsciousness and muscle relaxation.

Endotracheal Intubation

Preparation Steps

  • Essential equipment: at least 3 sizes of endotracheal tubes, stylet preparation.

  • Tube diameter and length considerations are crucial to avoid injuries (e.g., tracheal damage).

    • Proper placement evaluation via auscultation of lung sounds bilaterally.

Intubation Procedure

  1. Assess readiness (no swallowing reflex, relaxed muscles).

  2. Laryngoscope positioning for visualization of the airway.

  3. Rapid insertion of the endotracheal tube and securing post placement.

  4. Monitoring depth via capnograph and breath sound auscultation.

Vagal Tone and Complications

  • Increased vagal tone can lead to bradycardia; manageable with anticholinergics.

  • Risks include trauma, cuff over-inflation, and laryngeal swelling.

  • Importance of safety checks (circle checks) during the procedure.

Recovery Management

  • Continuous monitoring is essential during recovery; do not leave the patient unattended.

  • Anticipate and manage various recovery scenarios (e.g., pain, excitement).

  • Administer oxygen to support gas exchange and dilute inhalant residue in lungs until extubation.

Extubation Criteria

  • Signs for extubation readiness include the return of vital signs and reflexes.

  • Dogs typically extubated with a strong swallow reflex; cats with a strong pinna reflex to avoid laryngospasm.

General Nursing Care During Recovery

  • Promote smooth recoveries by avoiding stimulation and unnecessary tube manipulation.

  • Gentle techniques (pulling tongue, quiet communication) can aid in patient comfort.

  • Prioritize a longer, smoother recovery over a fast, excited one for both patient and anesthetist's well-being.