Venous Congestion And Cognitive Dysfunction After Cardiac Surgery

Postoperative cognitive dysfunction (POCD) is a common central nervous system complication after surgery and anesthesia. Its primary clinical manifestations include a significant decline in cognitive abilities after surgery and anesthesia, encompassing memory, attention, coordination, orientation, language fluency, and executive function. POCD may persist for weeks or even years, affecting patient recovery, prolonging hospital stays, and potentially leading to additional physical and mental illnesses, increased mortality, and a significant burden on patients and their families. In cardiac surgery patients, the incidence of POCD ranges from 30% to 80% in the weeks following the procedure. The brain tissue is enclosed in a rigid anatomical structure; when there is an obstruction to venous return from the brain, intracranial pressure can increase, and blood supply to the brain tissue can decrease, leading to central nervous system dysfunction. Systemic venous congestion can occur when there is right heart dysfunction or excessive volume load. When right heart failure and/or volume overload occurs, changes in right atrial pressure are transmitted to the venous system of organs throughout the body, with dilatation of the inferior vena cava (IVC), obstruction of blood return from the hepatic, portal, and renal veins, and abnormal venous flow signals and altered ultrasound Doppler flow patterns. The primary objective of this prospective cohort study is to explore if intraoperative systemic venous congestion is associated with POCD after cardiac surgery. This study will also investigate the relationship between intraoperative systemic venous congestion and postoperative complications, and the relationship between each separate venous congestion and POD after cardiac surgery.