Glycaemic Control in Cardiac Surgery Patients: a Double-Edged Sword

Glycaemic management is of paramount importance in the cardiac surgery setting. A growing body of evidence confirms a J-shaped relationship between blood glucose (BG) level and perioperative morbidity and mortality. On one hand, acute hypoglycaemia causes irreversible cerebral damage. On the other hand, hyperglycaemia increases the risk of infections, acute kidney injury, atrial fibrillation, low cardiac output syndrome, cerebrovascular accidents and cognitive impairment. Also, high BG variability, even within the therapeutic window, may deteriorate the outcome. Therefore, moderate perioperative insulin management is usually recommended, with target BG adjusted to individual needs and possibilities. Continuous BG monitoring is a promising tool that should help practitioners in everyday decision-making process of glycaemic control. This review summarises the current evidence-based knowledge on the perioperative management of hyperglycaemia.