Effects of statins on short and long-term cognitive impairment in patients with critical illness: a systematic review and meta-analysis

Purpose: The aim of the current study was to determine whether statins are effective in prevention of delirium and cognitive impairment in critically ill patients. Methods: A systematic search was performed of MEDLINE, EMBASE, the Cochrane Central Register, and all available Chinese databases to identify publications from inception to February 2018. Adults with no history of cognitive dysfunction, treated with statins in intensive care units, were included from observational studies and high-quality randomized controlled trials (RCT) after formal bias assessment. Results: Nine studies were included in the quantitative synthesis. Short-term trials included 2 RCTs, 5 prospective studies, and 2 retrospective studies. Pooled data demonstrated no reduction in delirium prevalence (RR, 0.93; 95% CI, 0.71-1.22). Long-term cognition studies included only one RCT, with a follow-up duration of 12 months. Results revealed no reduction of impaired cognition in statin-treated patients (OR, 1.07; 95% CI, 0.53-2.19). Conclusion: Despite some encouraging observational studies, present data shows no benefit for statins in reducing delirium for intensive care and long-term cognitive impairment.