Etomidate - Heart-friendly Induction Agent with Precautions.

    Etomidate is a hypnotic agent. It is a short-acting intravenous anaesthetic agent used for the induction of general anaesthesia and sedation. Of all of the available intravenous induction agents, etomidate consistently demonstrates the least direct myocardial depression in several in vitro models. Two well-designed studies using adult human atrial and ventricular tissue demonstrated no effect of etomidate on myocardial contractility in concentrations seen in clinical use.

    Dosing. Initial: 0.2 to 0.6 mg/kg IV over 30-60 seconds for induction of anesthesia; maintenance: 5-20 mcg/kg/minute.

Beneficial effects of etomidate are:

• rapid onset of action

• safe cardiovascular risk profile

• easy dosing profile

• slight suppression of ventilation

• lack of histamine liberation

• protection from myocardial and cerebral ischemia

• able to decrease intracranial pressure and maintain a normal arterial pressure in cases of traumatic brain injury 

But these beneficial effects of etomidate are offset by a number of adverse effects:

• Injection site pain. (Etomidate is water-insoluble and is thus formulated in propylene glycol, commonly producing pain on injection, which may be ameliorated by pretreatment with lidocaine and 1:1 dilution with sterile water. A new etomidate formulation dissolving the drug in a fat emulsion of medium and long-chain triglycerides virtually eliminates pain on injection in children

• Skeletal myoclonic movement

• Eye movement

• Hiccoughs are frequent

• Nausea and vomiting are frequent

• Etomidate will suppress adrenal function with a single induction dose.(A single dose of etomidate used for induction in pediatric patients undergoing cardiac surgery with cardio-pulmonary bypass suppresses the usual increase in plasma cortisol levels by inhibiting 11-ß-hydroxylase, the enzyme that converts 11-deoxycortisol to cortisol. Cortisol levels returned to normal 24 hours later. Thus, consideration should be given to administer additional supplemental corticosteroids in patients receiving corticosteroids or at risk of prolonged adrenal suppression.)

• Results of some studies. In a retrospective review of almost 32,000 people, etomidate, when used for the induction of anaesthesia, was associated 2.5-fold increase in the risk of dying compared with those given propofol.^wiki[29] People given etomidate also had significantly greater odds of having cardiovascular morbidity and significantly longer hospital stay.^wiki[29]