Mechanisms and Intervention Strategies of Perioperative Glycemic Variability on Postoperative Delirium

Delirium is a sudden change in attention, thinking, and awareness that can occur after heart surgery. It may slow recovery and is associated with longer hospital stays and poorer health outcomes. Patients undergoing heart surgery with cardiopulmonary bypass, also known as a heart-lung machine, may experience changes in blood sugar levels and in the body's response to insulin around the time of surgery. This study aims to investigate how fluctuations in blood sugar levels, known as glycemic variability, are related to postoperative delirium. It will also examine whether insulin resistance, a condition in which the body responds less effectively to insulin, helps explain this relationship. The study will evaluate intranasal insulin, which is insulin administered through the nose to reach the brain. Researchers will assess its effects on blood sugar fluctuations, insulin resistance, and the occurrence of postoperative delirium in patients undergoing heart surgery with cardiopulmonary bypass. The findings may help guide future approaches to protecting brain function and improving recovery after heart surgery.

Inclusion Criteria: * Age ≥ 18 years * Scheduled for elective cardiac surgery with CPB Exclusion Criteria: * History of psychiatric disorders, neurological diseases, or mild cognitive impairment (MCI) (Mini-Cog score \< 3) * Severe diabetes mellitus * Participation in other interventional studies * Coexistence of severe organic diseases * Nasal deformities, nasal diseases, or history of nasal surgery