Clinical Challenges of Glycemic Control in the Intensive Care Unit: A Narrative Review

Glucose control in patient admitted to the intensive care unit has been a topic of much debate over the past 20 years. The harmful effects of uncontrolled hyperglycemia and hypoglycemia in critically ill patients is well established. Although a large clinical trial in 2001 demonstrated significant mortality and morbidity benefits with tight glucose control in this patient population, the results could not be replicated by other investigators. The "Normoglycemia in Intensive Care Evaluation-Survival Using Glucose Algorithm Regulation" trial in 2009 established that tight glucose control was not only of no benefit, but in fact harmful due to the significant risk of hypoglycemia. The current guidelines suggest a moderate approach with the initiation of intravenous insulin therapy in critically ill patients when the blood glucose level is above 180 mg/dL. The most important factor that underpins glycemic management in intensive care unit patients is the consequent prevention of hypoglycemia. Robust glucose monitoring strategies and insulin protocols need to be implemented in order to achieve this goal.