- QUANTITATIVE SWEAT CHLORIDE TEST-(+)
- ↳ production of sweat is stimulated, sweat is collected (>75mg is needed), and sweat electrolytes are measured.
- ↳ normal: <40mEq/L
- ↳ (+) >60mEq/L
- ↳ infants: >40mEq/L (dx in infants younger than 3 mos of age)
- ↳ Chloride concentration of 40-60mEq/L are highly suggestive of CF and require a repeated test.
immunoreactive trypsinogen analysis and direct DNA analysis for mutant genes.
(+)atelectasis (partial or complete collapse of the lung) and obstructive emphysema (the air sacs of the lungs are damaged and enlarged).
PULMONARY FXN TEST:
(+)abn small airway fxn.
STOOL, FAT, ENZYME ANALYSIS:
72-hr stool sample is collected to check fat or enzyme (trypsin) content, or both (food intake is recorded).