Postoperative delirium biomarker identified An interdisciplinary team of HMS researchers at Beth Israel Deaconess Medical Center has identified a single protein present in the blood that is associated with increased risk of postoperative delirium. The finding sheds light on a potential pathophysiological mechanism underlying delirium and paves the way for a noninvasive, cost-effective test to guide prediction, diagnosis, and monitoring of delirium. Preoperative blood tests for these proteins could help physicians determine which patients are at higher risk for developing this form of confusion. Delirium, a common syndrome among older adults, is a form of acute confusion that is characterized by poor attention, disorientation, impaired memory, delusions, and abrupt changes in mood and behavior, particularly in critically ill patients in the ICU, in older patients with multiple health issues, and in those who have recently undergone surgery. Patients who experience delirium are also at increased risk of long-term cognitive decline.