But they note that no studies so far have been powered to detect such an effect.
“Debate about the clinical significance of etomidate’s effects on adrenal function has emerged in the critical care and emergency medicine literature after publication of data demonstrating the importance of intact adrenal function for survival in critical illness,” the investigators said in a March 26th online report in the Annals of Emergency Medicine.
Lead author Dr. Corinne M. Hohl, from the University of British Columbia, Vancouver, Canada, and colleagues conducted a systematic review of 20 relevant studies identified through a search of MEDLINE, EMBASE, and other sources. They included 18 randomized controlled trials, 1 nonrandomized trial, and 1 retrospective study. Overall, the randomized trials involved 951 patients, but two trials accounted for most of the subjects (one with 110 and the other with 469). The nonrandomized and retrospective study included 106 and 159 patients, respectively.
Compared to induction with other agents, etomidate induction resulted in significantly lower mean cortisol levels 1 to 4 hours later. The differences in levels ranged from 6.1 to 16.4 micrograms/dL.
At 7 to 12 hours after induction, however, cortisol values were “at or above baseline.”
None of the studies suggested that etomidate increased mortality. One trial (in 60 trauma patients) linked use of the drug with longer ventilation and hospital stays – but baseline injury severity scores were higher in the etomidate group.
The authors point out that while they saw no significant effect of the transient adrenal impairment on mortality, “no studies to date have been powered to detect a difference in mortality or time in the hospital, the ICU, or receiving ventilator support.”
Therefore, they conclude, until an effect on mortality can be conclusively excluded, it might be prudent to use other induction agents for rapid sequence intubation.
Ann Emerg Med 2010.