A nurse is providing teaching to the parents of an infant who is to undergo pilocarpine iontophoresis testing for cystic fibrosis.
Which of the following statements should the nurse include in the teaching?
A.
“A nurse will insert an IV prior to the test.”
B.
“We will measure the amount of protein in your baby’s urine over a 24 hour period.”
C.
“The test will measure the amount of chloride in your baby’s sweat.”
D.
“Your baby will need to fast for 8 hours prior to the test.”
The Correct Answer and Explanation is:
The correct answer is C. “The test will measure the amount of chloride in your baby’s sweat.”
Explanation:
Pilocarpine iontophoresis, commonly known as the sweat chloride test, is a diagnostic tool used primarily for diagnosing cystic fibrosis (CF). CF is a genetic disorder that affects the respiratory and digestive systems due to the production of thick, sticky mucus. The sweat chloride test is crucial because it measures the amount of chloride in the sweat, which helps confirm the diagnosis of CF.
How the Test Works:
- Preparation: Pilocarpine iontophoresis involves the application of a small amount of pilocarpine (a medication that stimulates sweating) to the skin. The pilocarpine is delivered using a mild electrical current through electrodes placed on the skin.
- Sweat Collection: The stimulated sweat is collected using a special device or absorbent pads. This sweat is then analyzed to determine the chloride concentration.
- Interpretation: In CF patients, chloride levels in sweat are typically higher than normal. A chloride level greater than 60 milliequivalents per liter (mEq/L) is indicative of CF, though results can vary depending on age and other factors.
Why Other Options Are Incorrect:
- Option A (“A nurse will insert an IV prior to the test”) is incorrect because the sweat chloride test does not require intravenous access. The test focuses on sweat analysis, not blood or fluid analysis.
- Option B (“We will measure the amount of protein in your baby’s urine over a 24-hour period”) is incorrect because urine protein measurement is not related to the sweat chloride test. It may be used for different diagnostic purposes, such as assessing kidney function or other conditions.
- Option D (“Your baby will need to fast for 8 hours prior to the test”) is incorrect because fasting is not required for the sweat chloride test. Unlike some other diagnostic tests, pilocarpine iontophoresis does not require fasting or dietary restrictions.
In Summary: The sweat chloride test is a non-invasive and effective method for diagnosing cystic fibrosis by measuring chloride levels in sweat. Accurate preparation and understanding of the test help ensure proper diagnosis and subsequent management of CF.