When should a tourniquet be released after venipuncture?

Releasing the tourniquet immediately after blood flow is established is the appropriate practice to minimize potential complications and ensure the accuracy of the specimen collected. When the tourniquet is in place, it causes venous distension, making the veins more prominent and easier to access. However, keeping the tourniquet on for too long can lead to hemoconcentration, which can alter the composition of the blood sample and affect test results.

By releasing the tourniquet right after blood flow is achieved, it allows for normal venous blood flow to resume, thereby reducing the risk of complications such as hemoconcentration and discomfort for the patient. This standard practice helps to ensure that the collected sample reflects the true physiological state of the patient at the time of blood collection.