Preventive effect of liraglutide on postoperative delirium in elderly patients undergoing cardiac surgery: protocol for a single-centre, randomised, double-blind, placebo-controlled trial.

INTRODUCTION: Postoperative delirium (POD) is a common and serious complication after cardiac surgery, particularly in elderly patients, and is associated with adverse short- and long-term outcomes. Effective preventive strategies remain limited. Liraglutide, a glucagon-like peptide-1 receptor agonist, has demonstrated potential neuroprotective, anti-inflammatory and metabolic benefits, which may reduce the incidence of POD. METHODS AND ANALYSIS: This is a single-centre, randomised, double-blind, placebo-controlled trial in elderly patients undergoing elective cardiac surgery. Participants will be randomised in a 1:1 ratio to receive liraglutide or placebo from the day before surgery until postoperative day 3. A total of 260 patients are planned to be enrolled in this study. The primary endpoint is the incidence of POD within 7 days, assessed using the Confusion Assessment Method (CAM) or CAM-intensive care unit. Secondary outcomes include delirium severity, neurocognitive and psychological function, cardiac function, clinical outcomes, major adverse cardiovascular events within 1 year and perioperative biomarker changes. Exploratory outcomes include functional MRI in selected subgroups and additional biomarker analyses. ETHICS AND DISSEMINATION: The protocol has been approved by the Medical Ethics Committee of Nanjing Drum Tower Hospital. Written informed consent will be obtained from all participants. Findings will be disseminated in peer-reviewed journals and academic conferences. TRIAL REGISTRATION NUMBER: ChiCTR2500106943.