NHA Phlebotomy Certification Practice Exam

What is the potential consequence of using a needle that is too large for a particular vein?

1. Improved blood flow

2. Increased risk of hemolysis

3. Faster blood draw

4. Less discomfort for the patient

The correct answer is: Increased risk of hemolysis

Using a needle that is too large for a particular vein can lead to an increased risk of hemolysis. Hemolysis occurs when red blood cells are broken down, and this can happen if the blood is subjected to excessive shear stress as it flows through a larger gauge needle. The larger diameter may create more turbulence and force in the blood sample, leading to the destruction of red blood cells. This can compromise the quality of the blood specimen and may affect the accuracy of various laboratory tests, especially those measuring cell components or hemoglobin. In the context of phlebotomy, it's important to select the appropriate needle size based on the size and type of the vein to minimize any potential damage to blood cells and ensure that samples are collected safely and effectively.