Role of Blood–Brain Barrier Permeability in Delirium Pathophysiology and Treatment

Delirium is a serious neuropsychiatric condition marked by acute confusion and cognitive decline, commonly affecting postoperative and critically ill patients. It is especially prevalent in older adults and those requiring intensive care, including patients undergoing major surgery or receiving mechanical ventilation. For anesthesiologists, delirium is a critical and often underrecognized postoperative complication with complex perioperative contributors. Intensive care unit patients with delirium face increased mortality, cognitive impairment, and persistent symptoms beyond discharge. Despite its clinical significance, the pathophysiology of delirium remains poorly understood, with no standardized classification or targeted therapy. In light of emerging evidence connecting blood-brain barrier (BBB) permeability to the onset of delirium, we found that BBB dysfunction may represent a key mechanism underlying its pathophysiology. Through a thorough examination of predisposing and precipitating factors that impair both BBB integrity and cognitive function, we identified many points of connection between BBB dysfunction and delirium specifically. We include here a summary of our diagnostic approach with the aim of improving therapeutic strategies based on preserving BBB function to prevent or mitigate delirium.