Screening for cystic fibrosis with chloride electrode. An investigation of sweat chloride with chloride electrode orion 417 in normal persons and in patients with cystic fibrosis.

An investigation of sweat chloride with chloride electrode Orion 417 in normal 
persons and in patients with cystic fibrosis. Sweat chloride values examined 
with Orion 417 direct-reading skin electrode were collected in a group 
of 811 normal persons and a group of 91 patients with 
cystic fibrosis and were evaluated for differences attributable to age and 
sex. In the normal group no significant difference was found between 
the two sexes. In the normal group the values among newborns 
are found to be considerably higher than in the rest of 
childhood. During the first month of life the values decrease to 
a steady level, which is maintained from the age of 1 
month to 15 years. After the age of 15 a steady 
increase takes place. With data gathered from the normal group we 
propose the following upper limits of "normal" for the sweat chloride 
test: 1 month - 15 years: Chloride 40 meq/l. 16 - 
25 years: Chloride 55 meq/l. Upon examination of the Cystic Fibrosis 
group, the sweat chloride values in all age groups were found 
to be above the upper limits of normal. The method is 
found valuable for large scale screening purposes for Cystic Fibrosis. 