## Clinical Context This patient has significant cardiovascular comorbidities — hypertension, coronary artery disease (CAD), and a reduced ejection fraction (EF 40%) — making him highly vulnerable to hemodynamic instability during induction. The anesthesiologist has already excluded propofol due to its vasodilatory and myocardial depressant effects. ## Why Etomidate Is the Most Appropriate Choice **Key Point:** Etomidate is the induction agent of choice in hemodynamically compromised patients because it produces minimal cardiovascular depression, maintaining heart rate, blood pressure, and cardiac output better than any other IV induction agent. **High-Yield:** Etomidate's cardiovascular profile: 1. Negligible effect on myocardial contractility 2. Minimal change in systemic vascular resistance (SVR) 3. Heart rate and blood pressure remain essentially unchanged 4. No histamine release 5. Preserves coronary perfusion pressure — critical in CAD Per Morgan & Mikhail's *Clinical Anesthesiology* and Miller's *Anesthesia*, etomidate is the preferred induction agent when cardiovascular stability is the primary concern (reduced EF, severe CAD, hemodynamic compromise). ## Why Ketamine Is NOT the Best Choice Here **Clinical Pearl:** Although ketamine stimulates the sympathetic nervous system and can maintain or increase blood pressure, this is a double-edged sword in CAD: - Ketamine increases heart rate, myocardial oxygen demand (MVO₂), and systemic blood pressure - In a patient with fixed coronary stenoses and reduced EF, tachycardia and increased afterload can precipitate myocardial ischemia or infarction - Ketamine is preferred in shock/hemorrhage states where sympathetic stimulation is beneficial, NOT in stable CAD with reduced EF where tachycardia is harmful ## Comparison of Induction Agents in Cardiac Compromise | Agent | BP Effect | HR Effect | Cardiac Output | Best Use | |-------|-----------|-----------|----------------|----------| | **Etomidate** | → | → | → | Reduced EF, CAD, hemodynamic compromise | | Ketamine | ↑ | ↑↑ | ↑ | Hemorrhagic/septic shock (not CAD with reduced EF) | | Thiopentone | ↓↓↓ | → | ↓↓↓ | Contraindicated here | | Propofol | ↓↓ | ↓ | ↓↓ | Contraindicated here | ## Adrenal Suppression — Contextual Note Etomidate causes transient adrenocortical suppression (inhibits 11β-hydroxylase) lasting 24–48 hours after a single induction dose. However, for an elective, short-duration laparoscopic procedure in a non-septic patient, this is clinically acceptable and does not outweigh the significant hemodynamic advantage etomidate provides over ketamine in this specific scenario. **High-Yield:** Etomidate is the induction agent of choice in: - Reduced ejection fraction / cardiomyopathy - Coronary artery disease (elective surgery) - Aortic stenosis - Any patient where hemodynamic stability is paramount ## Dosing Note Etomidate 0.2–0.3 mg/kg IV for induction; in elderly patients, reduce to 0.15–0.2 mg/kg. Pain on injection can be mitigated with prior lidocaine or using a large vein. *Reference: Morgan & Mikhail's Clinical Anesthesiology, 6th ed.; Miller's Anesthesia, 8th ed.*
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