Measurement of the Electrical Conductivity of Sweat

Abstract

Abstract 1. A method has been described for the measurement of the electrical conductivity of thermally induced sweat. 2. Conductivity data of sweat samples collected from 124 children ranging in ages from 4 weeks to 16 years is presented. Forty-seven patients have cystic fibrosis of the pancreas and exhibit a mean value for the sweat conductivity of 16,150 micromhos/cm. In the remaining 77 subjects, of which 6 were healthy and the others had miscellaneous illnesses, the mean value for the sweat conductivity is 5,560 micromhos/cm. All of the subjects with sweat conductivities less than 9000 micromhos/cm. did not have cystic fibrosis; all of the subjects with sweat conductivities greater than 12,000 micromhos/cm., with one exception, had cystic fibrosis. The intermediate range (9000 to 12,000 micromhos/cm.) comprised less than 10 per cent of the subjects studied. It has been shown that measurement of chloride and/or sodium concentration in sweat is a more reliable diagnostic index of cystic fibrosis of the pancreas.