Glycemic targets and approaches to management of the patient with critical illness

Hyperglycemia during critical illness is associated with adverse outcome. The proof-of-concept Leuven studies assessed causality, and revealed that targeting strict normoglycemia (80-110 mg/dL) with insulin improved outcome compared with tolerating hyperglycemia to the renal threshold (215 mg/dL). A large multicenter trial (NICE-SUGAR [Normoglycaemia in Intensive Care Evaluation and Survival Using Glucose Algorithm Regulation]) found an intermediate blood glucose target (140-180 mg/dL) safer than targeting normoglycemia. Differences in design and in execution of glycemic control at the bedside may have contributed to these results. In NICE-SUGAR (Normoglycaemia in Intensive Care Evaluation and Survival Using Glucose Algorithm Regulation), the blood-glucose target range in the control group was lower, there were problems to reach and maintain normoglycemia in the intervention group, and inaccurate handheld blood glucose meters and variable blood sampling sites were allowed. Inaccurate tools led to insulin-dosing errors with consequently (undetected) hypoglycemia and unacceptable blood glucose variability. Also, the studies were done superimposed upon different nutritional strategies. Thus, such differences do not allow simple, evidence-based recommendations for daily practice, but an intermediate blood glucose target may be preferable while awaiting better tools to facilitate safely reaching normoglycemia.