Tight Glycemic Control and Point-of-Care Testing

According to the hypothesis of tight glycemic control (TGC), inpatient morbidity and mortality will be reduced by processes and practices that ‘‘tightly’’ maintain blood glucose levels within a strictly defined range regardless of diabetic status (diabetes or not), acuity of illness, or admitting diagnosis. Until 2001, inpatient glycemic management focused solely on the diabetic patient with few reported studies that discussed hyperglycemic management of the nondiabetic patient. However, scattered studies looked at the prognostic impact of hyperglycemia in the nondiabetic inpatient population. One such study from 1975 dealt with the prognostic impact of hyperglycemia in the post–myocardial infarction population. 1 This study noted that patients with higher fasting blood-glucose levels within 72 hours of admission had a higher mortality. For the last 35 years, the prevailing notion was that hyperglycemia in the acutely ill nondiabetic inpatient was a consequence of illnesses as well as a marker of its severity. Hyperglycemia was also thought to be an adaptive response to injury necessary for survival and not necessarily a prognostic indicator of morbidity or mortality. 2,3 In this article, we discuss the current school of thought regarding prognostic implications of nondiabetic inpatient hyperglycemia, its management to achieve TGC, and the relationship of point-of-care testing to TGC. Inpatient hyperglycemia is referred to as stress hyperglycemia and has both endogenous and exogenous metabolic pathways. Endogenously, acute illness triggers insulin resistance (in 80% of critical-care patients), as well as a release of hormones associated with elevated blood-glucose levels, such as glucagon, epinephrine, cortisol, and growth hormone. 3 Exogenously, hyperglycemia results from the use of total parenteral nutrition and dextrose infusions. 4