 Hyponatremia, has become increasingly recognized as a cause of morbidity and mortality in hospitalized children. The main etiology of hyponatremia in these children has been attributed to the use of hypotonic maintenance IV fluids. The practice of providing IV solutions containing 20-30 mmolL of Na is based on physiological needs proposed by Holliday and Segarin 1957, derived from studies of 61 adults and children. The presence of non-physiologic ADH secretion in the great majority of hospitalized children due to nausea, stress, pain, and surgical interventions, has confirmed that Holliday and Segars recommendations are frequently inappropriately applied. To avoid the development of hyponatremia, it has been suggested that isotonic 0.9 NaCldextrose 5 should be the standard maintenance IV solution. 