Comments on Etomidate Usage in the Emergency Department

Certainly for emergency medicine specialists, sedative hypnotic agents play an important role during difficult times in their professional life. These molecules are indispensable agents, especially in the emergency department, for the induction of “rapid sequence intubation” performed during unprepared conditions or “procedural sedation and analgesia” for children and adults. Though not a novel drug, etomidate challenges all algorithms prevalent in the field of anesthesia over the last 10 years. I wanted to remind you and share my humble opinions about this agent, which has been subjected to many positive and negative comments. Etomidate is a preferred induction agent because of its substantially increased lipid solubility for critically ill patients whose blood pressure should be maintained at a stable level. At the beginning, consciousness of the patient is impaired because of a first-pass effect through the brain following its intravenous injection. A single bolus dose induces hypnosis within 10 s and terminates within 3–5 min. It does not have any analgesic effect. It depresses electroencephalography (EEG) activity and cerebral blood pressure similar to the effects of barbiturates. Because it does not affect the mean arterial pressure and decreases intracranial pressure without lowering cerebral perfusion pressure, it is especially useful in hemodynamically instable patients with increased intracranial pressure. Because etomidate is the only intravenous anesthetic agent that does not affect histamine release, it is also safe in patients with a reactive airway. For “rapid sequence intubation” and “procedural sedation and analgesia,” its intravenous doses are 0.2–0.4 mg/kg in adults and 0.1–0.2 mg/kg in children. Its effects start at the most within 15 s and end at the most within 15 min. Its adverse effects are as follows: • Nausea and vomiting • Injection side pain: For the treatment of pain along the intravenous route, opening of a large vascular access, saline infusion, and the use of a local analgesic are recommended. • Myoclonus: This can be seen in one-third of cases and is caused by interruption of the inhibitory synapses on the thalamocortical pathway. The use of opioid analgesics and benzodiazepines as premedication can decrease this side effect. Unfavorable effects of this side effect on patient’s clinical status have not been reported so far. However, when it is manifested in cases where it cannot be discriminated from seizure activity, it can lead to the conduction of unnecessary tests and a prolonged stay of the patient in the emergency department. • Suppression of the adrenocortical hormone: This can emerge as a result of the inhibition of 11-β hydroxylase enzyme. It certainly suppresses adrenocortical hormone synthesis in a dose-dependent manner. A single dose inhibits adrenocortical hormone synthesis for 5 h. Some studies have demonstrated its suppressive effects even after 12 h following its use. Owing to the abovementioned characteristics, as an induction agent, etomidate essentially resembles propofol and thiopental. Its extremely rapid onset together with short-acting effects decreases intracranial pressure. However, etomidate does not decrease blood pressure or cerebral perfusion pressure while depressing intracranial pressure, which may confer major advantages to etomidate. Etomidate can also be compared with ketamine. Both of these drugs do not decrease blood pressure, and they can be used in patients with reactive airways. As an important advantage, ketamine also has an analgesic effect. Despite this, ketamine increases endogenous catecholamine sensitivity, which can create problems, especially in adult patients carrying a risk of coronary disease. Besides, as an important difference, ketamine increases intracranial pressure and secretions. Because recovery from ketamine anesthesia in adults is somewhat problematic, it has established its place in daily practice in the pediatric age group. In adults, ketamine has been replaced by an opiod-etomidate combination. After briefly giving a reminder of the effects of etomidate, let us now discuss the main controversies. Although, etomidate is believed to be mostly beneficial for hemodynamically instable, critically ill patients, for this patient group, including patients with sepsis, the adrenal insufficiency-inducing effects of etomidate could be associ-