Cognitive Functioning After Circulatory Shock: A Prospective Observational Study

Cognitive impairment in intensive care unit (ICU) survivors is multifactorial and can affect especially memory, attention, and executive functions. This study aimed to determine the cognitive functioning of patients with circulatory shock immediately after ICU discharge and 3 months later.

This study, ASSESS-SHOCK 2, is a preplanned sub-study of the observational ASSESS-SHOCK study conducted at Helsinki University Hospital ICU. We included adults with circulatory shock, defined as hypotension requiring vasopressor infusion and concomitant signs of hypoperfusion. We excluded patients with severe neurological or psychiatric diagnoses, impairment of hearing or vision, developmental disability, and language barriers. Cognitive functioning of patients was assessed within 3 days of ICU discharge and 3 months thereafter with the Montreal Cognitive Assessment (MoCA) test. We defined cognitive impairment as MoCA score < 26 points. We also included data of 48 volunteer controls, tested once, to analyses.

Fifty-five patients underwent an assessment within 3 days of ICU discharge, and 36 of them completed a follow-up assessment at 3 months. At discharge median MoCA-score was 22 (IQR 17-25). At the 3 months follow-up, the median MoCA-score was 26.5 points (IQR 24.25-28) showing improvement from discharge to follow-up (p < 0.001). The prevalence of cognitive impairment at discharge was 78.2%, and, at the 3-month follow-up 44.4%. In the control group, the median MoCA score was 27 points (IQR 25-28) and the prevalence of cognitive impairment 33%.

We found cognitive impairment in more than three out of four ICU survivors immediately after ICU treatment for circulatory shock. We observed an improvement in cognitive functioning between ICU discharge and 3 months follow-up. These results have importance considering the optimal timing of information given to patients and when involving patients in decision-making.

This study used the MoCA score to investigate the change in cognitive impairment in patients who survived circulatory shock, from the time of discharge from intensive care to 3 months after discharge. Scores indicated more severe cognitive dysfunction compared to controls at the time of discharge, but these improved to match control scores 3 months later. The findings have important implications for strategies to inform and support newly discharged ICU survivors who have experienced circulatory shock.