Biomarker Predictors of Delirium in Acutely Ill Patients: A Systematic Review

Abstract

Delirium is a serious and common disorder that affects up to 80% of acutely ill patients, mainly the aged. In recent years, several studies pointed out possible biomarkers that could be used alone or in combination with other resources in the diagnosis and follow-up of critically ill patients who develop delirium. In this context, a systematic review was conducted to determine the predictive value of several biomarkers in acutely (critically and noncritically) ill adult patients with delirium. Studies that used the confusion assessment method (CAM) and CAM-intensive care unit as the diagnostic method were considered. The most recent search was performed in November 2017. There was no language restriction. Initially, 626 articles were screened and 39 were included in the study. A comprehensive evaluation of the abstracts resulted in the exclusion of 202 studies, leaving 39 articles as potentially relevant. Inflammatory markers, S100b and cortisol, could predict delirium occurrence in a specific subgroup population of critically ill patients.

Meta-analysis of ICU Delirium Biomarkers and Their Alignment With the NIA-AA Research Framework

“…Further studies directly examining post-ICU cognitive dysfunction and ADRD biomarkers are needed. In contrast to a recent systematic review 18 indicating that in studies of critically ill patients, S100 and CRP were associated with delirium, we did not find a significant association between ICU delirium and S100 or CRP in our pooled analyses. This discrepancy may be explained by differences in included studies.…”

“…This discrepancy may be explained by differences in included studies. As an example, for S100 , only 1 of the 6 studies by Michels et al 18 was included in our meta-analysis, whereas the other 2 studies in our meta-analysis 2 = 0.0; 2 = 0.8, df = 1 (P = .36); I 2 = 0%…”

CSF neurofilament light levels predict hippocampal atrophy in cognitively healthy older adults

“…Further, a few studies have assessed neuronal injury biomarkers in delirium. Some studies have found that neuronal injury biomarkers known to be increased in dementia are also increased in delirium (474), examples are S100β (448,475,476) and NFL (477,478), suggesting chronic neurodegeneration and/or acute neuronal injury in patients with delirium. A few studies have also assessed the relationship between AD biomarkers and delirium, one of these is paper III in this thesis.…”

Poor outcomes of delirium in the intensive care units are amplified by increasing age: A retrospective cohort study

“…Although the pathophysiology of ICU delirium remains unclear, existing studies related to ICU delirium mechanism have found that factors indicating systematic infl ammatory response, neuronal dysfunction and cortisol responses [37] are related to ICU delirium occurrence. Along with aging, endothelial function and cerebral perfusion get impaired, [38] the capacity of the brain to transmit signals and communicate reduces, [39] the hypothalamic-pituitary-adrenal (HPA) axis dysregulates, [40] and inflammatory response alters.…”