California Phlebotomy Certification Practice Exam

What effect does using povidone iodine during a capillary specimen collection have on potassium levels?

1. Decreased potassium level

2. No effect on potassium level

3. Increased potassium level

4. Potassium level stabilizes

The correct answer is: Increased potassium level

When povidone iodine is used during a capillary specimen collection, it can lead to an increase in potassium levels in the sample. This occurs because povidone iodine is known to have a high concentration of potassium, which can contaminate the blood specimen. When the specimen is collected from a capillary source, especially if the skin is not allowed to dry completely or if there’s leakage of the disinfectant into the sample, this external potassium can artificially elevate the measured levels of potassium. This is significant in laboratory diagnostics since inaccurate potassium readings can lead to misdiagnosis or inappropriate treatment. Understanding this interaction is important for phlebotomists and healthcare providers to ensure the integrity of the laboratory results and to avoid the potential for clinical errors caused by contamination during specimen collection.