Page 1048 - Saunders Comprehensive Review For NCLEX-RN

FIG. 35-3 Various effects of exocrine gland dysfunction in cystic fibrosis.

Box 35-7

Quantitative Sweat Chloride Test

▪ Production of sweat is stimulated (pilocarpine iontophoresis), sweat is collected,
and sweat electrolytes are measured (more than 75 mg of sweat is needed).
▪ Normally, the sweat chloride concentration is less than 40 mEq/L (40 mmol/L).
▪ Chloride concentration greater than 60 mEq/L (60 mmol/L) is a positive test
result (higher than 40 mEq/L (40 mmol/L) is diagnostic in infants younger than
3 months of age.
▪ Chloride concentrations of 40 to 60 mEq/L (40 to 60 mmol/L) are highly
suggestive of cystic fibrosis and require a repeat test.

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