Glycemic Targets and Approaches to Management of the Patient with Critical Illness

Abstract

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.

Hyperglycemia-induced diaphragm weakness is mediated by oxidative stress

“…The obvious treatment for hyperglycemia in critical illness is insulin therapy; however, the data that indicate that this approach prevents ICU acquired diaphragm weakness show that strict glycemic control with intensive insulin therapy is required. Moreover, recent studies suggest that this approach increases ICU mortality, primarily due to complications arising from hypoglycemia [73-75], and as such, current clinical recommendations for the management of hyperglycemia in critically ill patients do not support the use of strict glucose control. Importantly, the data from the present study show that hyperglycemia-induced respiratory muscle weakness can be prevented by administration of a superoxide scavenger (PEG-SOD), as this agent dramatically restored diaphragm function in hyperglycemic animals despite having no effect on glucose levels.…”

Nutritional Support in Hospitalized Patients with Diabetes Mellitus

“…Although there is ongoing debate on the optimal target blood glucose level, current studies suggest an optimal glycemic target of 140À180 mg/dL. Efficacy has been shown in cardiothoracic patients, however, when they have been treated with the goal blood sugar in the 100À140 mg/dL range [2,36,37].…”

Insulin treatment guided by subcutaneous continuous glucose monitoring compared to frequent point-of-care measurement in critically ill patients: a randomized controlled trial

“…The outcomes of two large intervention studies are in some way contradictory but the consensus is that hyperglycemia should be corrected, while avoiding hypoglycemia and high glucose variability [3][4][5][6][7][8]. On the basis of the available evidence, it seems preferable to maintain a blood glucose level around 8.0 mmol/L for the majority of critically ill patients [9,10].…”