Test Code SWEAT SWEAT CHLORIDE ANALYSIS

Important Note

Please call NorDx Customer Solutions at 800-396-5814 or 207-396-7830 to schedule testing at Bramhall (Maine Medical Center) Campus.

Additional Codes

Software	Test Code
Label Text	SWEAT
EPIC	LAB10270

Performing Laboratory

NorDx Laboratories

Useful For

Diagnosing cystic fibrosis

Method Name

Chloridometer Titration Method

Wescor Macroduct

Reference Values

Sweat Chloride results should always be evaluated in light of the patient’s clinical course.

Interpretation:

CF Unlikely: ≤ 29 mmol/L

Intermediate: 30-59 mmol/L

Indicative of CF: ≥ 60 mmol/L

DIAGNOSTIC CRITERIA:

The test results should be consistent with the clinical picture; no single laboratory result is sufficient to establish or rule out the diagnosis of CF. The criteria for the diagnosis of CF include; the presence of one or more characteristic phenotypic features, or a history of CF in a sibling, or a positive newborn screening test result; and an increased sweat chloride concentration by pilocarpine iontophoresis on two or more occasions, or identification of two CF mutations or demonstration of abnormal nasal epithelial ion transport. Two percent of patients with documented CF have sweat chlorides less than or equal to 60 mEq/L. Therefore, a normal sweat chloride value cannot be used as the sole criterion for exclusion of a CF diagnosis.

Reference: Adapted from – CLSI. Sweat Testing: Sample Collection and Quantitative Chloride Analysis; Approved Guideline – Third Edition; CLSI Document C34-A3; December 2009; Vol. 29: No. 27

Days and Times Test Performed

Monday through Friday

Report Available

1 Day

Specimen Type

Sweat – Minimum sweat volume is 15 ul from each collection site.

Specimen Collection and Handling

1. Sweat production is induced by an iontophoresis procedure and the chloride concentration is quantitated by mercuric titration.

2. Minimum age for testing is 48 hours.

Add On Capable

Not Permitted

Advance Beneficiary Notice Requirements

This test, when ordered on Medicare patients, is subject to the National Coverage Determination (NCD) policies. Please verify that the diagnosis code (ICD code) you have chosen demonstrates medical necessity for the test as documented in the physician’s patient record. The CMS web site is available to assist you with this verification. A properly executed Advance Beneficiary Notice (ABN) must be submitted with the specimen if medical necessity is not demonstrated by the ICD code chosen.

Performing Laboratory Location