Intraoperative Nasal Insulin Effect on Plasma and CSF Insulin Concentration and Blood Glucose

Intranasal insulin is reported to improves memory performance in patients suffering from cognitive impairment. The investigators have previously shown that intraoperative insulin administration preserves both short and long-term memory function after cardiac surgery. Applying intranasal insulin bypasses blood-brain barrier and cause elevation of insulin concentrations in the cerebrospinal fluid without major effects on peripheral insulin level. Patients undergoing major surgery are exposed to carbohydrate and insulin metabolism alteration. The goal of the study is to study the effect of intranasal insulin on blood glucose, plasma and cerebrospinal insulin concentration in patients undergoing cardiac surgery or endovascular thoracic aneurysm repair.