The critically ill child: hypoglycemia

HYPOGLYCEMIA represents a significant emergency situation in pediatrics. Although recent studies indicate that cerebral tissue can utilize substrates other than glucose, cose, especially in the newborn period and during prolonged fasting,1 no substrate can successfully correct the neurophysiologic sequellae of glucose deprivation on the central nervous system. Since permanent neurological effects of hypoglycemia correlate with the duration of time that cerebral tissue is deprived of glucose, early recognition and treatment of hypoglycemia is essential. The diagnosis of hypoglycemia obviously depends on demonstration of a significant reduction in blood glucose concentration. Diagnostic criteria, similar to those developed by Cornblath and Schwartz,2 have been widely accepted: two or more blood glucose values of less than 30 mg/100 ml in full-term infants; concentration of blood glucose less than 20 mg/100 ml in the neonate weighing less than 2,500 gm; blood glucose values of less than 40 mg/100 ml in the older infant and child. Since hypoglycemia is defined in terms of the concentration of blood glucose, it is essential to utilize analytic methods which are specific for glucose. The most common method utilizes glucose oxidase, although other methods provide appropriate specificity. A rapid modification of the glucose oxidase method is represented by Dextrostix,* although accurate application of this diagnostic aid to hypoglycemia requires considerable training and experience.3 Recently, a modification of the Dextrostix method has been reported, enabling reproducible measurement of values in the range of 20 to 40 mg/100 ml.4 Confirmation of results obtained by Dextrostix with reliable laboratory methods should be effected upon recognition of hypoglycemia.