Question

The newborn’s blood sodium level is low, at only 128, and they are receiving intravenous treatment in the hospital. What might cause this condition?

Answer

Low sodium hypernatremia in newborns can be caused by various factors:

  1. When fluid loss occurs, solute loss exceeds water loss, leading to hypervolemic hyponatremia.
  2. With a normal extracellular fluid volume, loss due to endocrine diseases or mediator abnormalities, such as syndrome of inappropriate antidiuretic hormone (SIADH) or thyroid dysfunction, adrenal cortex dysfunction.
  3. An increase in extracellular fluid volume, such as excessive hypotonic fluid intake or renal dysfunction leading to dilution of extracellular sodium, also known as dilutional hyponatremia. The symptoms of hyponatremia vary with the rate of blood sodium decrease. If changes in cell volume cause hypervolemic hyponatremia, symptoms may include severe circulatory collapse, cold extremities, weak pulse, decreased urine output, and sunken forehead.