pediatrics
Dehydration in Children
Practical Rehydration Example
A 7-month-old infant has diarrhea for 3 days with weight loss from 10 kg to 9 kg. The infant is currently producing 1 diarrheal stool every 3 hours and refusing to drink. Clinical findings of dry mucous membranes, poor skin turgor, markedly decreased urine output, and tachycardia with normal blood pressure and capillary refill suggest 10% fluid deficit. Rectal temperature is 37°C. Serum measurements are sodium, 136 mEq/L (136 mmol/L); potassium, 4 mEq/L (4 mmol/L); chloride, 104 mEq/L (104 mmol/L); and bicarbonate, 20 mEq/L (20 mmol/L). Fluid volumeis estimated by deficits, ongoing losses, and maintenance requirements. The total fluid deficit given 1 kg weight loss=1 L. Ongoing diarrheal losses are measured as they occur by weighing the infant’s diaper before application and after the diarrheal stool. Baseline maintenance requirements by the weight-based Holliday-Segar method are 100 mL/kg×10 kg=1000 mL/day=1000 mL/24 hours or 40 mL/hour. Electrolyte lossesresulting from diarrhea in a eunatremic patient (see table) are an estimated 80 mEq of sodium and 80 mEq of potassium. 