The study has three distinct objectives: to investigate the efficacy of early statins administration during an ICU stay for the prevention of ICU delirium; to determine any improvement in related neurocognitive sequelae coupled with standard clinical outcomes; and to study the biological effect of simvastatin on systemic markers of inflammation as related to the number of delirium- and coma-free days, and the potential of cholinesterase activity and β-amyloid as predictors of the risk of delirium and long-term cognitive impairment [12,13]. Here, BCHE is linked to Cognitive impairment.