[Cystic fibrosis revealed by dehydration with hypochloronatremic alkalosis in 3 infants and a neonate].

BACKGROUND--Acute dehydration with hypochloronatremic metabolic alkalosis is a classical complication of cystic fibrosis of the pancreas. Its progressive development as a revealing manifestation of the disease is rare as is its appearance in newborns. Case n. 1.--A 13 month-old girl was admitted because of status epilepticus. She was severely dehydrated (20% weight loss) but had normal diuresis. Investigations showed metabolic alkalosis, hypochloronatremia and hypokalemia. All the manifestations disappeared within 5 days with treatment but three sweat tests were abnormal. Case n. 2.--A 7 month-old girl was admitted because she suffered from progressive loss of weight (10%); she was dehydrated and had metabolic alkalosis plus hypochloronatremia, but her diuresis was normal. Two sweat tests were abnormal. Case n. 3.--A 4.5 month-old boy was admitted because he suffered from severe (12%) weight loss. His diuresis was normal despite dehydration; metabolic alkalosis and hypochloronatremia were found. Two subsequent sweat tests were abnormal. Case n. 4.--A 3 day-old girl was admitted suffering from meconium ileus. Two initial mechanism analysis for protein were abnormal. She had a cardiorespiratory arrest on the 13th day of life, when she had lost 14% of her birth weight; investigations showed metabolic alkalosis, hyponatremia (83 mEq/l), hypochloremia (45 mEq/l); kalemia was 5.9 mEq/l. Peritoneal dialysis was needed to correct hydroelectrolytic changes. A sweat test performed on the 26th day of life was also abnormal. Investigations performed during the periods of dehydration, and repeated later, showed transient functional kidney failure. None of the four patients had any respiratory or gastrointestinal clinical manifestations of cystic fibrosis. CONCLUSION--Metabolic alkalosis with hypochloronatremia plus progressive, severe dehydration in infants whose diuresis is paradoxically normal must be followed by examination for cystic fibrosis.