Continuous-Infusion Etomidate in a Patient Receiving Extracorporeal Membrane Oxygenation.

We describe a 16-year-old, 65-kg male deployed on extracorporeal membrane oxygenation (ECMO) for refractory respiratory failure secondary to ingestion of multiple substances. During his ECMO course, standard sedative and analgesic strategies failed and alternative medications were used. The patient received various dosages of fentanyl, morphine, hydromorphone, clonidine patches, dexmedetomidine, lorazepam, methadone, pentobarbital, olanzapine, and propofol. Despite administration of multiple agents, on day 29 of ECMO the patient experienced elevated blood pressures due to agitation, and continuous infusion etomidate was started. At the time of etomidate initiation, the osmolar gap was 8 mOsm/kg. During etomidate therapy, the blood pressure remained normal, sedative agents were slowly weaned, and the patient required few PRN medications. On day 6 of etomidate, the osmolar gap increased to 127 mOsm/kg and etomidate was discontinued. Continuous-infusion ketamine was started, but the blood pressure was not controlled. Metabolic acidosis is a known side effect of etomidate due to inclusion of propylene glycol as a pharmaceutical solvent in the formulation. Despite high-dose etomidate (20 mcg/kg/min) for approximately 6 days, our patient did not experience metabolic acidosis. Absence of this adverse effect caused us to question the role of the ECMO circuit. To our knowledge, this is the first report of the use of continuous-infusion etomidate during ECMO. Etomidate infusion could be considered in difficult-to-manage patients after other alternatives have failed.