European Academy of Paediatric Societies edition:3 location:Copenhagen date:23-26 October 2010
Context Targeting normoglycemia with intensive insulin therapy (IIT) improved short-term outcome of pediatric intensive care unit (PICU) patients, but concomitantly increased the incidence of hypoglycemia (1). Both hyperglycemia and hypoglycemia may adversely affect the developing brain in children.
Objectives We studied the impact of targeting normoglycemia with IIT on circulating markers of brain injury in critically ill children.
Methods This was a pre-planned analysis of critically ill pediatric patients included in a randomized controlled study on IIT. Patients were assigned to IIT targeting normal-for-age fasting blood glucose levels throughout intensive care or insulin infusion only to prevent excessive hyperglycemia. Serum S100B and neuron-specific enolase (NSE), biomarkers of astrocytic and neuronal damage, respectively, were measured on fixed days (n=700) and in a “nested case-control” design before and after hypoglycemia (n=126).
Main results Admission levels of S100B and NSE differed according to diagnosis and illness severity (P<0.0001). IIT did not affect the time course of these markers. Patients experiencing hypoglycemia during intensive care had higher S100B and NSE from admission onwards than those without hypoglycemia. In the nested case-control study, both markers decreased after hypoglycemia (P=0.001 and P=0.009), unlike in the “controls” on matched days.
Conclusions IIT in PICU did not evoke neurological damage detectable by circulating S100B and NSE, despite increased incidence of hypoglycemia. Elevated markers in patients with hypoglycemia were not caused by hypoglycemia itself, but rather reflect an increased risk of hypoglycemia in the most severely ill. This risk is difficult to capture by the classical illness severity scores.