Etomidate is contraindicated in sepsis and critical illness because it causes which specific endocrine complication?

Explanation

## Etomidate and Adrenocortical Suppression **Key Point:** Etomidate inhibits 11β-hydroxylase, a key enzyme in the final step of cortisol synthesis, leading to acute adrenocortical suppression even with a single bolus dose. ### Mechanism of Endocrine Toxicity 1. **Target enzyme:** 11β-hydroxylase (cytochrome P450 enzyme in zona fasciculata) 2. **Effect:** Blocks conversion of 11-deoxycortisol → cortisol 3. **Onset:** Occurs within minutes of IV administration 4. **Duration:** Cortisol levels remain suppressed for 4–8 hours after a single dose; prolonged suppression with infusions ### Clinical Consequences | Scenario | Risk | Outcome | |----------|------|----------| | **Single bolus in healthy patient** | Low | Transient cortisol ↓; usually tolerated | | **Sepsis/critical illness** | **HIGH** | Loss of stress response → cardiovascular collapse, mortality ↑ | | **Prolonged infusion** | **HIGH** | Persistent adrenal suppression, ARDS, MOF | | **Combination with other agents** | **HIGH** | Additive immunosuppression | **High-Yield:** Etomidate is **absolutely contraindicated** in septic shock and critical illness because these patients depend on endogenous cortisol surge for hemodynamic stability and immune response. Etomidate-induced suppression can precipitate refractory hypotension and death. **Warning:** Even a single 0.2 mg/kg bolus of etomidate can suppress cortisol for hours — this is NOT a dose-dependent phenomenon but an intrinsic property of the drug. **Clinical Pearl:** In septic shock requiring induction, **propofol** or **ketamine** are preferred because they do NOT suppress cortisol. If etomidate must be used (rare), concurrent hydrocortisone (50 mg IV q6h) is mandatory. ### Comparison with Other Agents | Agent | Cortisol Effect | Use in Sepsis | |-------|-----------------|----------------| | **Etomidate** | ↓↓ (suppression) | **CONTRAINDICATED** | | **Propofol** | No effect | Safe (but hypotensive) | | **Ketamine** | No effect | **PREFERRED** | | **Thiopentone** | No effect | Safe (but hypotensive) | **Mnemonic:** **ETOMIDATE = Endocrine Toxicity — 11β-hydroxylase Inhibitor** — remember the enzyme it blocks.