Cystic fibrosis of the pancreas. Diagnosis by sodium electrode sweat tests.

One of the most difficult and unreproducible procedures in clinical laboratories has been the measurement of electrolytes in sweat. The iontophoresis techniques for the diagnosis of cystic fibrosis of the pancreas, which are widely used, are fraught with difficulties.Measurement of sweat electrolytes with sodium or chloride electrodes is gradually replacing the iontophoresis methods. A simple modification of the sodium electrode technique was used for diagnosis in 11 cystic fibrosis patients and in 260 normal children. The values obtained with the sodium electrode clearly separated the normal children from those with cystic fibrosis.