We, therefore, conducted a prospective cohort study to investigate whether AChE, AChE normalized per gram of hemoglobin (AChE/Hgb), and BChE activities measured using point-of-care testing are associated with acute brain dysfunction (i.e., delirium and coma) during critical illness and whether they are predictive of long-term cognitive impairment, disability, and health-related quality of life in survivors of critical illness. This evidence concerns the gene BCHE and delirium.