Managing the dehydrated child.

Hypotonic fluid losses lead to hypertonic dehydration. Because the extracellular fluid compartment has the ability to draw fluid from the intracellular compartment, intravascular volume is better maintained in hypertonic dehydration than in isotonic or hypotonic dehydration. When the amount of weight loss is known, the fluid deficit can be easily calculated; otherwise, a clinical assessment of the percentage of dehydration is required.