Basic Principles on Anesthesia's Role in Neuromonitoring

Oct 17, 2024

Review flashcards

Lecture Notes: Neuromonitoring and Anesthetics

Key Individuals and Companies

  • Sam Johnson: Chief Development Officer at Accurate Neuromonitoring, previously COO of NeuroAlert.
  • Frank: CEO at Accurate Neuromonitoring.
  • Accurate Neuromonitoring: Acquired NeuroAlert, operates extensively in New York, New Jersey, and Georgia.

Clinical Assignments

  • Chiara: Clinicals in the Atlanta area, potential opportunities with Accurate Neuromonitoring.
  • Mara: Clinicals in New York area might be impacted.

Clinical Preparation

  • Gather immunization records and have a current TB skin test.
  • Required vaccinations: Flu (upcoming), MMR, Varicella, Tdap.
  • CPR training: Can be renewed with Adam over Zoom.

Role of Anesthesia in Neuromonitoring

  • Anesthesia can lead to false positives in neuromonitoring.
    • False Positives: Alerts given without surgical cause.
    • False Negatives: Assuming anesthesia change causes signal drop, missing actual surgical cause (iatrogenic events).
  • Importance of understanding anesthesia's impact on neuromonitoring.

Types of Anesthetic Agents

Inhalational Agents

  • Main Issue: Cause more false positives.
  • Changes in anesthesia levels (MAC) can affect motor evoked potentials.

Intravenous Agents

  1. Bolus: Large single dose injected through IV (e.g., Propofol).
  2. Infusion: Steady state delivery over time.

Specific Drugs

  • Propofol (Diprivan): Induction agent, quick on/off, impacts EEG in high doses.
  • Barbiturates: Act on GABA-A receptors, can cause burst suppression.
  • Benzodiazepines: Anti-anxiolytics, usually pre-op, can cause 'benzo buzzing'.
  • Opioids: Pain management, Remifentanil preferred for short half-life.
  • Ketamine: Enhances signals, risks emergence delirium.
  • Etomidate: Previously common, now less due to adrenal suppression.
  • Dexmedetomidine (Presidex): Offers sedation and analgesia without respiratory depression.

Neuromuscular Blocking Agents (NMBAs)

  • Depolarizing (e.g., Suxamethonium): Short-term paralysis, causes muscle fasciculations.
  • Non-Depolarizing (e.g., Rocuronium): Longer-lasting, competitive inhibition at receptor sites.
  • Reversal: Sigamidex for non-depolarizing agents.

Vasoactive Drugs

  • Vasoconstrictors: Increase blood pressure (e.g., Ephedrine).
  • Vasodilators: Reduce blood pressure (e.g., Nitroprusside).

Heart Rate Management

  • Bradycardia (<50 bpm): Treated with Epinephrine or Atropine.
  • Tachycardia (>100 bpm): Treated with Beta Blockers or Calcium Channel Blockers.

BIS Monitor

  • Measures depth of anesthesia, uses EEG/EMG data.
  • Not always reliable, 45-second delay in data processing.

Anesthesia Techniques

TEVA (Total IV Anesthesia)

  • No inhalational agents; preferred for neuromonitoring.

Balance Technique

  • Combination of IV and low-level inhalational agents.

Nitrous Narcotic Technique

  • Uses nitrous oxide, less common today.

Conclusion

  • Understand how various anesthetic techniques and drugs impact neuromonitoring.
  • Balance anesthesia needs with monitoring effectiveness.

Upcoming Topics

  • Detailed study on pathology and its implications in neuromonitoring.

These notes cover the extensive discussion on the role and impact of different anesthetic techniques and medications in the context of neuromonitoring, touching on their implications for clinical practices and patient safety.