Dehydration: Isonatremic, Hyponatremic, and Hypernatremic Recognition and Management.

Dehydration is one of the leading causes of pediatric morbidity and mortality throughout the world. Diarrheal disease and dehydration account for 14% to 30% of worldwide deaths among infants and toddlers. (1) In the United States, as recently as 2003, gastroenteritis was the source for more than 1.5 million office visits, 200,000 hospitalizations, and 300 deaths per year. The rotavirus vaccine has significantly decreased the incidence of rotaviral gastroenteritis, and now norovirus is the leading cause in the United States. Water, which is essential for cellular homeostasis, comprises about 75% of body weight in infants and up to 60% in adolescents and adults. Without water intake, humans would die within a few days. (2) The human body has an efficient mechanism of physiologic controls to maintain fluid and electrolyte balance, including thirst. Thesemechanisms can be overwhelmed in disease states such as gastroenteritis because of rapid fluid and electrolyte losses, leading to dysnatremia, which is the most common electrolyte abnormality in hospitalized patients. (3) AUTHOR DISCLOSURE Dr Powers has disclosed no financial relationships relevant to this article. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.