Neonatal glucose metabolism: differential diagnoses, evaluation, and treatment of hypoglycemia.

Hypoglycemia is one of the most common clinical care issues facing the neonatal practitioner. Increasing evidence indicates that neonatal hypoglycemia may have long-term neurologic effects. Care is complicated by the lack of a clearly defined threshold for hypoglycemia in term and preterm infants, however, and by highly variable clinical signs and symptoms. Furthermore, many infants with low blood glucose measurements do not exhibit obvious signs of impairment. The complexity of neonatal glucose metabolism is illustrated by the variety of conditions producing or associated with both neonatal hypo- and hyperglycemia. Maintenance of euglycemia is especially challenging in the sick or low birth weight neonate. This article defines euglycemia by its range and reviews the differential diagnoses and etiology of hypoglycemia--as well as the principles of its management--in the neonatal period.