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

Abstract

1. Karen S. Powers, MD, FCCM* 1. *Pediatric Critical Care, Golisano Children’s Hospital, University of Rochester School of Medicine, Rochester, NY. Clinicians need to recognize the signs and symptoms of dehydration to safely restore fluid and electrolytes. After completing this article, readers should be able to: 1. Understand that the signs and symptoms of dehydration are related to changes in extracellular fluid volume. 2. Recognize the different clinical and laboratory abnormalities in isonatremic, hyponatremic, and hypernatremic dehydration. 3. Know how to manage isonatremic dehydration. 4. Know how to manage hyponatremic dehydration. 5. Know how to manage hypernatremic dehydration. 6. Recognize how to avoid as well as treat complications of fluid and sodium repletion. 7. Understand which patients are candidates for oral rehydration. 8. Know the proper fluids and methods for oral rehydration. 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. These mechanisms 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) Infants and young children are …