Learn Anesthesia

Analgesia

  • Remifentanil:
    • Mechanism: Ultra-short-acting μ-opioid receptor agonist, rapidly metabolized by plasma esterases.
    • Uses: Intraoperative analgesia, procedural sedation, controlled hypotension.
    • Best for: Short surgeries requiring precise, titratable analgesia with rapid offset.
    • Special considerations: No cumulative effect, risk of acute tolerance, can cause respiratory depression and hypotension.
    • Population/Clinical Use: Ideal for neurosurgery, cardiac surgery, and TIVA cases requiring fast recovery. Also good for quick pain relief during operations such as when incisions are being made.
  • Fentanyl:
    • Mechanism: Potent μ-opioid receptor agonist, metabolized in the liver.
    • Uses: Induction and maintenance of anesthesia, intraoperative and postoperative analgesia.
    • Best for: Hemodynamically stable patients, cases needing longer-acting opioid analgesia.
    • Special considerations: Minimal histamine release, can cause respiratory depression, chest wall rigidity in high doses.
    • Population/Clinical Use: Used in cardiac surgery (due to hemodynamic stability), epidural/spinal anesthesia, and general perioperative pain control.
  • Dexmedetomidine:
    • Mechanism: Selective α2-adrenergic agonist, providing sedation, anxiolysis, and analgesia without respiratory depression.
    • Uses: Sedation in ICU patients, intraoperative anesthesia adjunct, multimodal analgesia.
    • Best for: Patients at risk of respiratory depression, opioid-sparing anesthesia.
    • Special considerations: Causes bradycardia, hypotension, but preserves airway reflexes and natural sleep-like sedation.
    • Population/Clinical Use: Ideal for awake intubations, ICU sedation, and opioid-sensitive patients (e.g., OSA, elderly).

📚 References

1️⃣ Miller RD. Miller’s Anesthesia. 9th ed. Philadelphia, PA: Elsevier; 2020.

2️⃣ Morgan GE, Mikhail MS, Murray MJ. Morgan & Mikhail’s Clinical Anesthesiology. 6th ed. New York, NY: McGraw Hill; 2018.

3️⃣ Steiner J. Anesthesia Made Easy: The Survival Guide to Make Your First Anesthesia Rotation a Success. 2nd ed. Independently Published; 2019.