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Fluids and Electrolytes

Disorders affecting the body fluids and electrolytes are treated by supplying maintenance requirements, correcting volume and electrolyte deficits, and by replacing ongoing abnormal losses.


Maintenance Fluid and Electrolytes

Sensible losses, primarily urinary, account for approximately 50% of daily fluid requirements.

Caloric requirements for growth can be estimated as equivalent on a kcal-for-mL basis to water requirements.

Factors that increase the requirements for calories and water are fever (10% for each degree), physical activity,

Abnormal losses, such as those arising from nasogastric aspiration, prolonged diarrhea or burns, should be measured, and replaced on a volume for volume basis.

Estimation of Deficit

Estimation of volume depletion should assess fever, vomiting and/or diarrhea, and urine output. The type and amount of fluid loss are determined. Recent feeding, including type and volume of food and drink, and weight change are determined.

The physical examination aids in estimating the extent of dehydration. anuria

The percent dehydration is used to calculate the milliliters of body water deficit per kilogram of body weight.

Isonatremic Dehydration

The most common cause of dehydration in infants is diarrhea.

Children who have a brief illness and anorexia usually present with isotonic dehydration.

Oral Rehydration

Moderate volume depletion should be treated with oral fluids. The majority of patients who have gastroenteritis can be treated with oral rehydration therapy.

Small aliquots of oral hydration solution (Ricelyte, Pedialyte, Resol)