A decision-theoretic approach to consistent tight glycemic control in critical care patients

Insulin alone may be insufficient to regulate blood glucose concentrations in critical illness. Previously we have presented ´Glucosafe´, a decision support system that recommends insulin infusion rates and rates of enteral and intravenous feeding, based on penalty functions. This study presents a general method by which the scaling of these penalty functions can be optimized. The method is based on an analysis of scaling factors under simulation of steady-state conditions in different insulin resistance states, and analysis of the obtained optimized values under simulations of hyper- and hypoglycemia. Optimization resulted in recommendations that kept blood glucose concentrations close to normal, the total amount of nutrition and the amount of ingested calories close to 100% of daily requirements, and insulin doses at levels that not unduly put the patient at risk of hypoglycemia.