In this episode, I’ll discuss the use of etomidate in the ICU.
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Etomidate
Etomidate is a non-barbituate, benzylimidazole general anesthetic agent.
By far the most common use for etomidate in ICU patients is as an induction agent during rapid sequence intubation.
Etomidate can also be used for deep sedation for procedures such as joint reduction or cardioversion, but this is most commonly done in the emergency department.
Dose, duration, & administration
The dose of etomidate as an induction agent is 0.3 mg/kg IV push. Expect this dose to provide sedation for between 3 and 5 minutes. Note that if a paralytic is used, this duration of action is shorter than either succinylcholine or rocuronium. A pharmacist present during rapid sequence intubation should account for the difference in duration between the sedative and paralytic used and ensure the patient does not experience anesthetic awareness by facilitating additional sedation for the patient.
The rapid offset of etomidate is due to redistribution. For this reason, etomidate must be administered quickly, over 30-60 seconds. Administering too slowly will prevent adequate sedation from occurring.
Etomidate can cause considerable pain on injection so it should be given through the largest vein possible.
If etomidate is used for procedural sedation, the dose is 0.1 to 0.2 mg/kg. This dose produces deep sedation where the cardiovascular and respiratory systems should continue to function. However, the care team should be prepared to rescue the patient with airway maneuvers or intubation if they slip into a state of general anesthesia.
Adverse effects
Myoclonus occurs frequently after etomidate is given but this has no clinical significance.
Etomidate should be hemodynamically neutral, without effect on the heart rate or blood pressure. An exception to this rule are patients who are elderly with significant cardiac disease. Consider cutting the dose in half or using another induction agent for these patients.
Adrenal insufficiency occurs after continuous infusion of etomidate; not with single doses. This is why etomidate is never used for sedation as a continuous infusion. In fact, etomidate can be used off-label as a continuous infusion for Cushing Syndrome.
Conflicting data from retrospective studies raised the possibility that single doses of etomidate used for rapid sequence intubation could cause adrenal insufficiency. It appears that it does slightly increase the risk of adrenal insufficiency. However prospective trials demonstrate that using a single dose of etomidate has no effect on clinically meaningful patient outcomes.
New molecule based on etomidate
A branded alternative to etomidate is undergoing animal studies. This new medication is called ET-26 HCl. It has anesthetic potency and hemodynamic stability similar to etomidate, but it causes less adrenocortical hormone synthesis suppression than etomidate while having similar spatial orientation recovery from anesthesia.
Whether the decrease adrenal suppression is clinically relevant will no doubt be a matter of future debate.
Even if it does not replace etomidate as an induction agent the possibility exists that it may become a new option for continuous sedation in critically ill patients.
Airway pharmacology in-depth
If you would like to know more about the role of a pharmacist during intubation, I go in-depth on the topic in my Airway Pharmacology Masterclass that is available in my Critical Care Pharmacy Academy.
I cover how the decision to intubate is made, all medications used to facilitate airway placement, types of airway scenarios, and medications used to treat the complications from airway placement.
You can learn more at pharmacyjoe.com/academy.
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