For what purpose is chlorhexidine primarily used during a blood draw?

Chlorhexidine is primarily used as an antiseptic during a blood draw to reduce the risk of infection. It effectively kills a wide range of bacteria, viruses, and fungi on the skin, thereby rendering the site of the venipuncture sterile. This reduction in microbial load is essential in preventing contamination of the blood samples and minimizing the possibility of introducing pathogens into the bloodstream.

When preparing a patient for a blood draw, healthcare professionals typically clean the skin with chlorhexidine to ensure that the area is free from any potential infectious agents. This practice is vital in both clinical and research settings, as maintaining aseptic technique is crucial for obtaining accurate and reliable test results and for protecting patient health.

The other options do not accurately describe the primary use of chlorhexidine in this context. While it is not used as a stabilizer for blood specimens, a preservative in serum tubes, or for balancing blood pH, its primary role remains focused on infection control during procedures that involve breaches in the skin barrier, such as phlebotomy.