Statin use and risk of delirium in the critically ill.

Abstract

Delirium is common in intensive care unit (ICU) patients and is a predictor of worse outcomes and neuroinflammation is a possible mechanism. The antiinflammatory actions of statins may reduce delirium. To determine whether critically ill patients receiving statin therapy had a reduced risk of delirium than those not on statins. A prospective cohort analysis of data from consecutive ICU patients admitted to a UK mixed medical and surgical critical care unit between August 2011 and February 2012; the Confusion Assessment Method for ICU was used to determine the days each patient was assessed as being free of delirium during ICU admission. Delirium-free days, daily administration of statins, and serum C-reactive protein (CRP) were recorded. Four hundred and seventy consecutive critical care patients were followed, of whom 151 patients received statins. Using random-effects multivariable logistic regression, statin administration the previous evening was associated with the patient being assessed as free of delirium (odds ratio, 2.28; confidence interval, 1.01-5.13; P < 0.05) and with lower CRP (β = -0.52; P < 0.01) the following day. When the association between statin and being assessed as free of delirium was controlled for CRP, the effect size became nonsignificant (odds ratio, 1.56; confidence interval, 0.64-3.79; P = 0.32). Ongoing statin therapy is associated with a lower daily risk of delirium in critically ill patients. An ongoing clinical trial, informed by this study, is investigating if statins are a potential therapy for delirium in the critically ill.