Acute Kidney Injury and Delirium: Kidney–Brain Crosstalk

Delirium is widely recognized as a form of fluctuating dysfunction of the brain and occurs in up to 70% of the critically ill [1]. It is associated with increased morbidity, longer hospital stay, cognitive decline with associated loss of quality of life, and death [1–4]. Recognition of delirium remains a challenge. Completion of delirium screening involves first using a validated sedation scale to assess eligibility for cognitive assessment, followed by a validated delirium screening tool. This may not be possible to complete if patients are in a coma, unable to understand the language or have established cognitive dysfunction (e.g., dementia, mental disorders) [5, 7]. Furthermore, delirium assessments will only reflect the cognitive state of the patient at the time of the assessment, making it difficult to capture this fluctuating cognitive disorder. As a result, the prevalence of delirium is likely to be underestimated. Furthermore, with no proven effective pharmacological therapy, delirium in the critically ill continues to pose a healthcare burden and a management conundrum for clinicians [8–10].