Burst-suppression and Postoperative Delirium: Comment

The recent report by Pedemonte et al.1 of their substudy the Minimizing ICU Neurologic Dysfunction with Dexmedetomidine-induced Sleep (MINDDS) study2 emphasized relationship between electroencephalogram (EEG) burst-suppression during cardiopulmonary bypass and delirium in elderly patients undergoing cardiac surgery. It raises several important points regarding potential for cerebral monitoring to identify who may be at risk significant postoperative neurologic complications, including cognitive dysfunction. However, interpreting these complex relationships requires certain safeguards minimize false discovery, thus maximize confidence a study’s conclusions. These include, but are not limited to, clear adherence prespecified aims priori hypotheses, development data statistical analytic plan before accessing data, consideration moderating effects from intervention parent trial. In this case, example, were derived an ongoing randomized controlled trial investigating dexmedetomidine on delirium. would seem reasonable then any analysis adjusted use dexmedetomidine. Clarification as whether how was done useful.Several other aspects study might also benefit additional clarity. For reporting ordered prestated hypotheses seems have been modified. primary hypothesis stated introduction that “preexisting impairment accounts CPB.”1 is curious, then, article’s title, subsequent study, principally focuses opposed preexisting impairment. This particularly notable because power states “primary objective detect difference mean preoperative scores no groups.”1 current analysis, they state, likely underpowered.Although there potentially delirium, one could plausibly mediated via EEG burst-suppression, reported should baseline cognition burst suppression, delirium-related analyses being secondary, and/or exploratory, fully multiple comparisons. Indeed, although some mention made adjustments reduce it where done. Furthermore, authors “data plans defined written after accessed,”1 much mining undertaken settled which results chosen reported. actual found (assessed using abbreviated Montreal assessment) statistically (P = 0.965 table 1).These limitations dissuade reader considering described, fact quite meaningful. without adequate adjustment unit randomization, analytical developed accessed, organization around one, does raise question undue emphasis placed “positive” surrounding “negative” related cognition.The author declares competing interests.