Neonatal dehydration and electrolyte disorders

Water constitutes the most prevalent substance within the human body, representing a fundamental component of bodily fluids. This vital element is indispensable for maintaining cellular homeostasis, accounting for approximately 75% of body weight in term infants. Water plays a pivotal role in a multitude of physiological processes. Dynamic alterations in body composition and fluid distribution are observed during the intrauterine period, labor, and the early postnatal period. The equilibrium of body fluid balance and distribution is contingent on the balance between water intake and loss. Dehydration is a prevalent issue in neonates, associated with considerable morbidity and mortality rates, and failure to promptly identify and manage this condition can result in severe complications. Dehydration is classified into three forms according to serum osmolality: hypernatremic, normonatremic (isonatremic), and hyponatremic dehydration. Sodium, potassium, magnesium, calcium, and phosphorus are vital for the maintenance of normal biochemical reactions and homeostatic functioning. Newborns in need of fluid electrolyte support should be evaluated by physical examination and other parameters (low urine volume, high urine density, high serum Na+), and treatment should be started rapidly.