Associations between markers of inflammation and cholinergic blockade and delirium in intensive care unit patients: A pilot study

The purpose of this study was to determine the associations of serum C-reactive protein (CRP) and plasma anticholinergic activity (PAA) with delirium in critically ill and injured patients. Prospective cohort study of 32 patients admitted a university-based intensive care unit. All patients were evaluated for delirium with the Confusion Assessment Method for the Intensive Care Unit, and blood was collected for measurement of serum CRP and PAA. These biomarkers and other factors, including patient demographics, intubation, and Acute Physiology and Chronic Health Evaluation (APACHE) Ⅱ and Sequential Organ Failure Assessment (SOFA) scores were compared between patients who developed delirium and those who did not. Furthermore, the levels of serum CRP and PAA were examined for correlation with each other. Intubated and mechanically ventilated patients were more likely to be delirious than non-intubated patients (p ＜ 0.001). The APACHE Ⅱ and SOFA scores were significantly higher in delirious patients than in non-delirious patients (p ＝ 0.007 and p ＝ 0.04, respectively). Serum CRP levels were significantly higher in intubated patients (p ＜ 0.02) as were PAA levels (p ＝ 0.001). A moderately strong correlation was found between serum CRP and PAA in the enrolled patients (Spearman's rho ＝ 0.65, p＜0.0001). Inflammation and cholinergic blockade, as measured by serum CRP and PAA levels, respectively, were associated with delirium in this study of critically ill patients, and serum CRP and PAA were correlated with each other.

delirium

inflammation

C-reactive protein (CRP)

acetylcholine

Confusion Assessment Method for the Intensive Care Unit (CAM-ICU)