pediatrics
Neonatal Hypernatremia
Key Points
Hypernatremia is usually due to dehydration (eg, caused by diarrhea, vomiting, high fever); sodium overload is rare. Signs include lethargy, restlessness, hyperreflexia, spasticity, hyperthermia, and seizures. Intracranial hemorrhage, venous sinus thrombosis, and acute renal tubular necrosis may occur. Diagnose by finding serum sodium concentration>150 mEq/L (>150 mmol/L). If the cause is dehydration, restore circulating blood volume with 0.9% saline and then give 5%dextrose/0.3% to 0.45% saline solution IV in volumes equal to the calculated fluid deficit. Rehydrate over 2 to 3 days to avoid a too-rapid fall in serum sodium, which can have significant adverse consequences. 