Long-term cognitive impairment after ICU treatment: a prospective longitudinal cohort study (Cog-I-CU).

In this prospective cohort study we aimed to investigate the trajectory of the cognitive performance of patients after discharge from an intensive care unit (ICU). Special consideration was given to patients with suspected premorbid cognitive impairment who might be at risk for the development of dementia. Clinical characteristics were collected until discharge. The premorbid cognitive state was estimated by a structured interview with a close relative. Cognitive outcome was assessed using the Consortium to Establish a Registry of Alzheimer's Disease (CERAD) Plus battery and the Stroop Color and Word Test at the time of discharge from ICU and 9 months later. The results of the study group were compared to an established healthy control group and to normative data. A total number of 108 patients were finally included. At the time of discharge, patients underperformed the healthy control group. In linear regression models, delirium during the ICU stay and the factor premorbid cognitive impairment were associated with poorer cognitive outcome (p = 0.047 and p = 0.001). After 9 months, in 6% of patients without evidence of premorbid cognitive impairment long-lasting deficits were found. In patients with suspected premorbid cognitive impairment, performance in tests of executive function failed to improve.