Hypochloremic metabolic alkalosis as presentation of cystic fibrosis. Report of two cases

Introduction: We describe the cases of two patients with hypochloremic metabolic alkalosis either as the initial presentation of cystic fibrosis (case 1) or as part of a second cystic fibrosis exacerbation (case 2). Clinical cases: Two patients, 6 and 9 months old, were brought to the hospital because of cough, fever, and dyspnea. The first had a syndrome of recurrent bronchial obstruction, without the diagnosis of CF on admission. Both presented with difficulty for breathing, dehydration, and malnutrition. Arterial blood gases showed metabolic acidosis, hypokalemia, and severe hypochloremia. Treatment with sodium chloride and potassium improved their electrolyte balance and acid-base status. They did not have renal or gastrointestinal losses of chloride. CF and pseudo-Barter's syndrome were diagnosed. Conclusion: Metabolic alkalosis can be the initial manifestation of CF in infants with recurrent bronchiolitis and short stature suspicious of having CF. It can also be the expression of an acute exacerbation in patients with known CF. Opportune diagnosis and treatment are important to decrease morbidity.