Don't Sugar Coat It: Glycemic Control in the Intensive Care Unit

Stress hyperglycemia is the transient increase in blood glucose as a result of complex hormonal changes that occur during critical illness. It has been described in the critically ill for nearly 200 years; patient harm, including increases in morbidity, mortality, and lengths of stay, has been associated with hyperglycemia, hypoglycemia, and glucose variability. However, there remains a contentious debate regarding the optimal glucose ranges for this population, most notably within the past 15 years. Recent landmark clinical trials have dramatically changed the treatment of stress hyperglycemia in the intensive care unit (ICU). Earlier studies suggested that tight glucose control improved both morbidity and mortality for ICU patients, but later studies have suggested potential harm related to the development of hypoglycemia. Multiple trials have tried to elucidate potential glucose target ranges for special patient populations, including those with diabetes, trauma, sepsis, cardiac surgery, and brain injuries, but there remains conflicting evidence for most of these subpopulations. Currently, most international organizations recommend targeting moderate blood glucose concentration to levels <180 mg/dL for all patients in the intensive care unit. In this review, the history of stress hyperglycemia and its treatment will be discussed including optimal glucose target ranges, devices for monitoring blood glucose, and current professional organizations' recommendations regarding glucose control in the ICU.