What is the purpose of using a tourniquet during blood collection?

The purpose of using a tourniquet during blood collection is to engorge the veins, which makes them more prominent and easier to access for a successful venipuncture. When a tourniquet is applied to the upper arm, it temporarily restricts blood flow, causing the veins to fill with blood and become distended. This physiological response is crucial for healthcare professionals when locating a suitable vein, especially in patients with difficult venous access. The visibility and palpability of these engorged veins facilitate the insertion of the needle, ultimately leading to a more efficient and less painful blood collection process.

Other options, while relevant to blood collection processes, do not accurately reflect the primary role of a tourniquet. For instance, a tourniquet does not prevent bleeding (which is managed differently during the collection), it is not intended for cleaning the area (which is typically done with antiseptic wipes), and it does not serve to stabilize the patient, as stabilization involves different techniques and equipment.