Acid-base disturbances in dehydrated patients with cystic fibrosis : four case reports with review of literature.

Most episodes of vomiting, reduced intake and diarrhoea in children can be evaluated and treated without additional tests. However, when the degree of clinical dehydration is not in line with the patient's medical history, other diagnoses should be suspected. In the presence of a hyponatraemic hypochloraemic metabolic alkalosis, cystic fibrosis (CF) should be included in the differential diagnosis, especially if there is failure to thrive even in the absence of respiratory symptoms. Furthermore, young patients diagnosed with CF have a higher risk for an acute electrolyte decompensation caused by increased salt and fluid losses. We present 4 paediatric cases to raise the awareness of electrolyte disturbances in CF patients.