An assessment of body water metabolism and electrolyte balance plays an important role in the early medical management of preterm infants and sick term infants coming to neonatal intensive care. Intravenous or intra-arterial fluids given during the first several days of life are a major factor in the development, or prevention, of morbidities such as intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC), patent ductus arteriosus (PDA), and bronchopulmonary dysplasia. Clinicians must pay close attention to the details of maintaining and monitoring body water and serum electrolytes, and the management of fluid infusion therapies.
Bodily fluid balance is a function of the distribution of water in the body, water intake, and water losses. Body water distribution gradually changes with increasing gestational age of the fetus. At birth these gestational changes in body water are reflected in the developing maturity of renal function, trans-epidermal insensible water losses, and neuroendocrine adaptations. One must account for these variables when deciding the amount of infusion fluids to administer to an infant.