Induction Dose of Etomidate for Adults
The recommended induction dose of etomidate for typical adult patients is 0.3 mg/kg IV, administered over 30 to 60 seconds, with a dosing range of 0.2 to 0.6 mg/kg depending on individual patient factors. 1
Standard Dosing Protocol
The FDA-approved dose for induction of anesthesia is 0.3 mg/kg IV, which represents the usual dose for most adult patients and those over 10 years of age 1
The acceptable dosing range extends from 0.2 mg/kg to 0.6 mg/kg, allowing for individualization based on hemodynamic status and clinical context 1
Administer the dose over 30 to 60 seconds to minimize side effects while achieving rapid loss of consciousness 1
Dose Modifications for Specific Populations
In hemodynamically compromised patients, consider reducing the dose to 0.15 mg/kg to minimize cardiovascular effects while maintaining adequate sedation 2
Geriatric patients may require reduced doses due to altered pharmacokinetics and increased sensitivity to anesthetic agents 1
Higher doses (>0.3 mg/kg) are associated with increased risk of respiratory depression, particularly in patients over 55 years of age 2, 3
Clinical Context: Rapid Sequence Intubation
For RSI in critically ill adults, the Society of Critical Care Medicine recommends etomidate 0.3 mg/kg IV as a first-line induction agent due to its favorable hemodynamic profile 2, 4
The 0.2-0.3 mg/kg dose range used in RSI studies showed no increased mortality compared to other induction agents (OR 1.17; 95% CI 0.86-1.60) 2, 5
When using etomidate for RSI, it must be followed immediately by a neuromuscular blocking agent (succinylcholine 1-1.5 mg/kg or rocuronium 0.9-1.2 mg/kg) to prevent awareness during paralysis 3, 4
Important Safety Considerations
Oxygen desaturation requiring supplemental oxygen occurs in approximately 5% of patients, with higher risk in those receiving doses ≥0.23 mg/kg 2
Myoclonus (involuntary muscle movements) occurs in more than 60% of patients when minimal premedication is used, though this is generally self-limited 6
Pain on injection occurs in up to 80% of patients when administered into small peripheral veins, but drops to approximately 7% when using larger veins 6
Postoperative nausea and vomiting occurs in up to 30% of patients and is unrelated to the dose administered 6
Critical Pitfall to Avoid
Do not use higher doses (>0.3 mg/kg) in elderly patients or those with respiratory compromise, as doses of 0.23 mg/kg or higher in patients over 55 years were associated with oxygen desaturation requiring bag-assisted ventilation in 4 of 5 cases 2. When hemodynamic instability is present, err on the side of lower dosing (0.15-0.2 mg/kg) rather than standard dosing 2.
Adrenal Suppression Controversy
While etomidate causes transient adrenal suppression (demonstrated by blunted ACTH stimulation tests at 4-6 hours post-dose), corticosteroid administration following etomidate is NOT recommended, as multiple RCTs showed no mortality benefit 2, 4
The clinical significance of this biochemical adrenal suppression remains unclear, as overall mortality was not increased in meta-analyses of critically ill patients 2, 5