Neonatal hypoglycemia and hypocalcemia

Neonates are at risk of developing hypoglycemia, particularly neonates of diabetic mothers.

 Hypoglycemia is defined by a plasma glucose concentration less than 40 mg/dL in the preterm neonate, less than 50 mg/dL for the term neonate younger than 3 days old, and less than 60 mg/dL in the term neonate older than 3 days of age. 

Neonates are at risk of hypoglycemia secondary to their poorly developed system for the maintenance of adequate plasma glucose concentrations. In addition, patients receiving total parenteral nutrition with high dextrose concentrations are at risk for hypoglycemia if the infusion is interrupted. Also, patients with poor nutritional status or liver disease often have inadequate hepatic glycogen stores and are also at risk. 

Preterm neonates also are at risk of developing hypocalcemia. 

Hypocalcemia in the neonate is defined by a plasma ionized calcium concentration less than about 1.1 mEq/dL. 

Fetuses develop their calcium stores during the third trimester, so that the preterm neonate has inadequate calcium stores at birth.

Hypocalcemia might occur intraoperatively as a result of citrated blood transfusions or during an exchange transfusion. The rapid infusion of citrate that occurs with citrated blood or fresh frozen plasma transfusions can result in hypotension secondary to hypocalcemia. The hypotension can be minimized by the administration of calcium gluconate, 1 to 2 mg intravenously for every 1 mL of blood transfused.