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

The primary purpose of using a tourniquet during blood collection is to engorge the veins and make them more visible. By applying a tourniquet above the site where the blood will be drawn, venous blood flow is temporarily restricted, leading to an increase in pressure within the veins. This causes the veins to expand and fill with blood, making them stand out more clearly against the surrounding tissue. As a result, it becomes easier for the healthcare provider to locate a suitable vein for venipuncture, enhancing the efficiency of the blood draw and minimizing the likelihood of multiple needle sticks.

While factors like the speed of the collection process and patient comfort may be considered during the procedure, the primary and most critical objective of the tourniquet’s application is to improve vein visibility. This helps to ensure a successful blood collection with minimal discomfort to the patient.