Letter to Cuthbertson et al.

Excerpt

To the editor: Cuthbertson et al. questioned the safety of single-dose etomidate, a valuable drug for intubation of patients with sepsis [1]. The fatal flaw in Cuthbertson’s study was confounding by indication. Etomidate may have been chosen for sicker patients. The authors recommended that physicians enrolling patients in the study not use etomidate. Among induction agents, only etomidate and ketamine are considered hemodynamically safe. In light of the pressure not to use etomidate, physicians in this study probably chose etomidate only for the most unstable patients. From the authors: “Another possible explanation could be that etomidate was used more commonly in patients with higher severity of illness due to its improved cardiovascular stability… We do not know the patient’s severity of illness at the time etomidate was used so cannot say to what degree their severity of illness on trial entry and subsequent outcome was directly influenced by etomidate use… Data on reasons for etomidate use were not collected” (our emphasis). This prospective observational study did not collect data on the most obvious potential confounder. How can a claim about the effects of etomidate be made when relevant baseline information was not collected at the right time? …