Brain autopsy findings in intensive care unit patients previously suffering from delirium: A pilot study☆
Introduction
Delirium is defined as an acute change or fluctuation in mental status combined with inattention and either an altered level of consciousness or disorganized thinking [1]. This is a very prevalent condition, with 50% to 80% of patients in medical, surgical, or trauma intensive care units (ICUs) affected [1], [2], [3]. Delirium in ICU patients is associated with longer hospital stays [3], new cognitive impairment at discharge [4], and an increased risk of mortality [5]. Given our current knowledge and the emerging importance of this problem, work has begun to address possible interventions to prevent delirium in ICU patients [6], [7], [8]. Despite well-documented accounts of delirium as a problem for our ICU patients and possible strategies to prevent acute brain dysfunction, the neuropathologic findings of ICU patients who had delirium have only recently begun receiving attention, and very little is currently known.
The purpose of the present exploratory study and case series was to retrospectively examine the brain autopsies of deceased ICU patients in whom we had prospectively measured daily delirium and drug exposure data to determine if any common neuropathologic lesions were noted in these deceased critically ill patients.
Section snippets
Methods
From 2002 through 2008, a total of 379 patients admitted to a Vanderbilt University Medical Center medical, surgical, or trauma ICU suffering from delirium have been enrolled in the Maximizing Efficacy of Targeted Sedation and Reducing Neurologic Dysfunction (MENDS) trial [5], Modifying the Incidence of Delirium (MIND) study, and ongoing Bringing to Light the Risk Factors and Incidence of Neuropsychological Dysfunction in ICU Survivors (BRAIN-ICU) study. Data were gathered prospectively on
Results
Of the 379 patients available from within the databases, 34% died while in the ICU, and 7 (2%) had an autopsy of their brain by a neuropathologist (Table 1). These 7 patients were identified in the study databases, and information regarding the number of days each suffered with delirium, sedatives and/or analgesics received, cause of death, and number of days with hypotension and/or hypoxia are presented in Table 2. All patients included in this study were delirious at the time of death and
Discussion
The results of this pilot study complement past research [10], [11], [12], [13] regarding the hypothesis that impaired cerebral blood flow, cerebral hypoxia, and cerebrovascular disease may be involved in the development of delirium in ICU patients. Of the brain autopsies we analyzed, 86% showed evidence of hypoperfusion and gross and microscopic cerebrovascular disease. Given the results of past functional studies, these findings were expected and may represent a contributing factor to the
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No financial funds were needed in preparing this manuscript, and we have no conflicts of interest to disclose.