What is the recommended use of etomidate (amidate) in the emergency room (ER) setting, particularly for critically ill or injured patients with suspected head trauma, stroke, or severe respiratory distress?

Etomidate Use in the Emergency Room

Primary Recommendation

Etomidate (0.3 mg/kg IV) is the preferred first-line induction agent for rapid sequence intubation in critically ill patients in the emergency department, including those with suspected head trauma, stroke, or severe respiratory distress, due to its superior hemodynamic stability and cerebroprotective properties. 1, 2

Dosing and Administration

• Standard dose: 0.3 mg/kg IV administered as a single bolus over 30-60 seconds 2, 3
• In hemodynamically compromised patients, consider reducing to 0.15-0.2 mg/kg to minimize cardiovascular effects while maintaining adequate sedation 4
• Do NOT exceed 0.3 mg/kg, as higher doses (>0.3 mg/kg) increase risk of respiratory depression, particularly in patients over 55 years of age 2, 4
• Titration approach: The American Heart Association recommends incremental dosing of 20 mg every 10 seconds until loss of consciousness rather than rapid bolus 1

Specific Clinical Scenarios

Head Trauma and Stroke Patients

• Etomidate is ideal for patients with suspected intracranial pathology because it decreases intracranial pressure by 20-30% while maintaining cerebral perfusion pressure 3
• Cerebral blood flow reduction is uniform and proportional to decreased oxygen utilization, providing cerebroprotection 3
• For patients with GCS ≤8, etomidate provides optimal conditions while protecting against secondary brain injury 2

Hemodynamically Unstable Patients

• Etomidate has minimal cardiovascular effects and maintains cardiac output, peripheral circulation, and pulmonary circulation even in patients with severe cardiovascular disease 3
• Unlike thiopental, propofol, or midazolam, etomidate does not cause significant hypotension in most patients 5
• Critical caveat: Geriatric patients with hypertension may experience decreases in heart rate, cardiac index, and mean arterial blood pressure 3

Severe Respiratory Distress

• Etomidate causes only slight elevation in PaCO2, making it safer than alternatives in respiratory compromise 3
• Oxygen desaturation occurs in approximately 5% of patients, with higher risk at doses ≥0.23 mg/kg in patients over 55 years 4

Critical Sequencing Requirements

• The sedative-hypnotic agent (etomidate) MUST be administered BEFORE the neuromuscular blocking agent to prevent awareness during paralysis 1, 2, 4
• Follow etomidate immediately with either:
  • Succinylcholine 1-1.5 mg/kg IV (first-line when no contraindications) 1, 4
  • Rocuronium 1.0-1.2 mg/kg IV (when succinylcholine contraindicated) 2, 4
• Administer the neuromuscular blocker as early as practical after induction to minimize apnea time 2

Adrenal Suppression Controversy

• Etomidate causes transient adrenal suppression lasting 6-8 hours that is unresponsive to ACTH stimulation 3, 6
• This represents blockage of 11-beta-hydroxylation within the adrenal cortex 3
• However, corticosteroid administration following etomidate is NOT recommended, as multiple RCTs showed no mortality benefit 1, 4
• Meta-analyses demonstrate no mortality difference between etomidate and other induction agents (OR 1.17; 95% CI 0.86-1.60) 4
• The most recent 2025 meta-analysis of 23,926 patients confirmed no significant difference in 30-day survival between etomidate and ketamine (OR 0.92,95% CI 0.68-1.24) 7

When to Consider Ketamine Instead

• Pediatric patients with septic shock: Ketamine is explicitly recommended over etomidate due to adrenal suppression concerns 4
• Adult septic patients: While evidence is mixed, some guidelines suggest ketamine preference in sepsis, though the 2025 meta-analysis showed no survival difference 4, 7
• Patients with depleted catecholamine stores: Ketamine may cause paradoxical hypotension despite sympathomimetic properties 1, 4
• Important consideration: Ketamine requires higher post-intubation vasopressor support (OR 0.71,95% CI 0.53-0.96) compared to etomidate 7

Common Pitfalls and How to Avoid Them

• Have vasopressors immediately available as both etomidate and the intubation procedure can cause hypotension in critically ill patients 2
• Ensure full neuromuscular blockade before attempting intubation using a peripheral nerve stimulator if uncertain 1
• Position patient in semi-Fowler position (head-up tilt) to improve first-pass success and reduce aspiration risk 2, 4
• Maintain mean arterial pressure >90 mmHg and systolic blood pressure >110 mmHg during the procedure in head-injured patients 2
• When using rocuronium, ensure sugammadex is available for reversal in "cannot intubate, cannot ventilate" scenarios 1, 2

Minor Side Effects

• Pain on injection, myoclonic movements, and hiccups may occur but are not clinically significant 5
• Vomiting occurs in approximately 4-10% of patients 4
• Nausea and vomiting are transient and manageable 5

Onset and Duration

• Onset of action: 5-15 seconds (typically within one minute) 3, 5
• Duration of anesthesia: 3-5 minutes with standard 0.3 mg/kg dose 3, 5
• Rapid metabolism in the liver with elimination half-life of approximately 75 minutes 3