Association of Plasma Biomarkers for Neurological Injury and Postoperative Delirium After Cardiac Surgery

Delirium is one of the most common complications after cardiac surgeries, incidence of which is 20\~70%. Causes and pathophysiology of delirium has not been elucidated yet, however, inflammatory response of the nervous system, imbalance of neurotransmitters and ischemia-reperfusion injury of brain tissue are thought to play a big role. 'Neurofilament light (Nfl)' and 'Tau' are proteins that comprise neurons, which are released into blood during acute brain injury. Increased serum concentrations of these markers are acknowledged to be associated with worse clinical outcomes in patients with acute brain injury. These proteins are also closely linked to degenerative changes in the nervous system and cognitive decline in Alzheimer's disease. Therefore, the increase in blood levels of 'Nfl' and 'Tau' may be related to the development of delirium. The aim of this study is to investigate the association between 'Nfl' and 'Tau', serum markers of damage of the nervous system, and the development of delirium after cardiac surgery.