A 52-year-old male with hypertension and coronary artery disease is scheduled for elective laparoscopic cholecystectomy. The anesthesiologist must choose between propofol and etomidate for induction. Which feature best distinguishes etomidate from propofol in this high-risk cardiac patient?

Explanation

## Distinguishing Etomidate from Propofol: Hemodynamic Profile ### Cardiovascular Stability — The Key Discriminator **Key Point:** Etomidate is uniquely characterized by **minimal cardiovascular depression** and preservation of systemic vascular resistance and blood pressure, making it the agent of choice in hemodynamically unstable or high-risk cardiac patients. ### Comparative Pharmacology | Feature | Propofol | Etomidate | |---------|----------|----------| | **BP & SVR** | ↓↓ (20–30% reduction) | Maintained or ↑ | | **Heart Rate** | ↓ or unchanged | Unchanged or ↑ | | **Cardiac Output** | ↓ (due to ↓ SVR & contractility) | Maintained | | **Airway Reflexes** | Abolished | Preserved (relatively) | | **Onset Time** | 30–40 sec | 30–40 sec | | **Injection Pain** | Yes (common) | Minimal | | **Adrenal Suppression** | No | **Yes (single dose)** | ### Why Etomidate Excels in Cardiac Risk 1. **Sympathomimetic effect:** Etomidate causes mild catecholamine release, offsetting direct myocardial depression. 2. **Preserved baroreceptor reflexes:** Unlike propofol, etomidate does not cause profound vasodilation. 3. **Maintained coronary perfusion pressure:** Critical in CAD patients. **Clinical Pearl:** In a 52-year-old with CAD and hypertension, etomidate's hemodynamic stability is the **single most important advantage** over propofol. The trade-off is adrenal suppression with single bolus (though clinically insignificant in one-time induction). **High-Yield:** Etomidate is the **gold standard induction agent for hemodynamically unstable patients** — sepsis, hypovolemia, cardiogenic shock, severe cardiac disease. ### Why Other Options Are Incorrect - **Airway reflexes:** Both agents abolish airway reflexes; etomidate preserves them *relatively* better, but this is not the primary discriminator. - **Onset time:** Both have identical onset (30–40 sec); no difference. - **Injection pain:** Propofol causes pain; etomidate does not — but this is a minor comfort issue, not a clinically critical discriminator in a cardiac patient. [cite:KD Tripathi 8e Ch 12]