[A case of hypernatremic dehydration due to breast-feeding].

The authors report an 11-day-old exclusively breast-fed female, with a birth weight of 3 300 g, who had suffered from dehydration stage I, with acute renal failure and metabolic acidosis, with 170 mmol/L of serum sodium. Renal ultrasounds were normal but the rate of sodium in mother's milk was three times higher than controls (87 versus 21 mmol/L). Intravenous rehydration allowed the correction of hydroelectrolytic disorders.