Electrolyte Concentrations in Sweat and Saliva

Abstract

Studies conducted in our laboratories in connection with the diagnosis of cystic fibrosis of the pancreas in children led us to the comparison of electrolyte concentrations in the sweat and saliva in patients with this disease. The sodium and chloride determination in sweat as performed by di Sant' Agnese * proved to be a very dependable test in diagnosing cystic fibrosis of the pancreas. Chloride concentration above 60 mEq/liter occurred, with but few exceptions, in the sweat of those who had cystic fibrosis of the pancreas. Sodium concentrations presented a greater overlap, but no patients with cystic fibrosis of the pancreas had values of less than 80 mEq/liter. In order to collect sweat the children are placed in a plastic bag for about an hour, as described by Shwachman.³Because this procedure is uncomfortable and rather time-consuming, it may not always be easy to perform on older infants and