To the Editor:

We have read with interest the article by Eun-Ah et al. [1], but feel that two aspects of this study must be clarified and discussed.

First, the authors may have underestimated hypoactive delirium, as this is often misdiagnosed and mistreated due to inconsistencies in the diagnosis itself. Delirium subtypes were designated as hypoactive, hyperactive, or mixed based on observed behavior and Emergence Delirium (ED) was rated using a four-point scale and the Pediatric Anesthesia Emergence Delirium tool, both of which cannot assess hypoactive delirium [2]. Consequently, raters could not properly assess hypoactive and mixed delirium. To correctly assess pediatric delirium, the Cornell Assessment Pediatric Delirium or the PreSchool Confusion Assessment Method for the ICU should have been used [3].

Finally, the results of this study do not support the conclusion as there was no placebo group. Hence, it is unclear that dexmedetomidine and midazolam are efficacious in preventing ED.