NHA Phlebotomy Certification Practice Exam

What is the primary purpose of applying a tourniquet during venipuncture?

1. To disinfect the area

2. To improve vein prominence

3. To ensure patient comfort

4. To prevent blood flow

The correct answer is: To improve vein prominence

The primary purpose of applying a tourniquet during venipuncture is to improve vein prominence. When a tourniquet is applied above the site where blood will be drawn, it temporarily restricts blood flow in the veins. This causes the veins to fill with blood, making them larger and more visible, which facilitates easier identification and access for the needle insertion. Improving vein prominence is crucial for successful venipuncture as it minimizes the chances of complications, such as hemolysis or difficulty in obtaining the sample. When the veins are more pronounced, it increases the likelihood of a successful draw on the first attempt, which is beneficial for both the patient and the healthcare provider. The other options, while related to the procedure, do not accurately reflect the main purpose of the tourniquet. Disinfection of the area is important for preventing infection but is achieved through cleaning methods rather than the use of a tourniquet. Patient comfort is always a consideration during medical procedures but is not the primary reason for applying a tourniquet. Lastly, while the tourniquet does temporarily prevent blood from flowing out of the vein, that is a secondary effect rather than the principal intent when it is utilized during the venipuncture process.