Sepsis-Associated Encephalopathy: from Pathophysiology to Progress in Experimental Studies

Sepsis is an organ dysfunction caused by an uncontrolled inflammatory response from the host to an infection. Sepsis is the main cause of morbidity and mortality in intensive care units (ICU) worldwide. One of the first organs to suffer from injuries resulting from sepsis is the brain. The central nervous system (CNS) is particularly vulnerable to damage, mediated by inflammatory and oxidative processes, which can cause the sepsis-associated encephalopathy (SAE), being reported in up to 70% of septic patients. This review aims to bring a summary of the main pathophysiological changes and dysfunctions in SAE, and the main focuses of current experimental studies for new treatments and therapies. The pathophysiology of SAE is complex and multifactorial, combining intertwined processes, and is promoted by countless alterations and dysfunctions resulting from sepsis, such as inflammation, neuroinflammation, oxidative stress, reduced brain metabolism, and injuries to the integrity of the blood-brain barrier (BBB). The treatment is limited once its cause is not completely understood. The patient's sedation is far to provide an adequate treatment to this complex condition. Studies and experimental advances are important for a better understanding of its pathophysiology and for the development of new treatments, medicines, and therapies for the treatment of SAE and to reduce its effects during and after sepsis.