pediatrics
Dehydration in Children
Diagnosis of Dehydration in Children
Clinical evaluation In general, dehydration is defined as follows: Mild: No hemodynamic changes (about 5% body weight in infants and 3% in adolescents) Moderate: Tachycardia (about 10% body weight in infants and 5 to 6% in adolescents) Severe: Hypotension with impaired perfusion (about 15% body weight in infants and 7 to 9% in adolescents) However, using a combination of symptoms and signs to assess dehydration is a more accurate method than using only one sign. Another way to assess the degree of dehydration in children with acute dehydration is change in body weight; all short-term weight loss>1%/day is presumed to represent fluid deficit. However, this method depends on knowing a precise, recent preillness weight. Parental estimates are usually inadequate; a 1-kg error in a 10-kg child causes a 10% error in the calculated percentage of dehydration—the difference between mild and severe dehydration. Laboratory testing is usually reserved for moderately or severely ill children, in whom electrolyte disturbances (eg, Hypernatremia , 