What is the primary reason for using a tourniquet during venipuncture?

The primary reason for using a tourniquet during venipuncture is to restrict blood flow and engorge veins. By applying the tourniquet, the blood flow to the area where the venipuncture will occur is temporarily halted. This action causes the veins to fill with blood, making them larger and more visible. The engorged veins are easier to access, allowing for a more successful and efficient blood draw.

Using a tourniquet does not directly prevent infection; infection control measures typically involve proper skin preparation and wearing gloves. While maintaining patient comfort is important, the application of a tourniquet can sometimes cause discomfort or a sensation similar to pressure, so its primary purpose is not comfort. Additionally, the act of cleaning the area prior to drawing is about sanitization and minimizing the risk of contamination, rather than the purpose of the tourniquet itself.