Question
What are the causes of low sodium levels in newborns?
Answer
Low sodium levels in newborns can be caused by fluid loss where solutes are lost more than water, resulting in hypotonic dehydration; or when extracellular fluid volume is essentially normal but electrolyte loss is abnormal due to endocrine disorders, such as syndrome of inappropriate antidiuretic hormone secretion (SIADH) or dysfunction of the thyroid or adrenal cortex. It may also be due to excessive extracellular fluid volume, such as the intake of too much hypotonic fluid, renal dysfunction in water excretion, leading to dilution of extracellular sodium, known as dilutional hyponatremia. As hyponatremia progresses, fluids shift into the cells, which can manifest as symptoms of brain cell edema, such as drowsiness, listlessness, coma, and seizures. Accompanying low sodium levels can also lead to neuro muscular excitability changes, such as decreased muscle tone and weakened tendon reflexes. Depending on the child’s condition, if the blood sodium level is slightly low, treatment should not only identify the cause but also treat the symptoms accordingly.