What is the maximum duration a tourniquet should be left on during venipuncture?

The maximum duration a tourniquet should be left on during venipuncture is 60 seconds. Keeping the tourniquet on for longer than this can lead to complications such as hemoconcentration, where blood components—like proteins and cells—concentrate due to the decreased volume of plasma. This change can potentially affect test results by giving an inaccurately high concentration of certain substances, leading to misinterpretation of the patient's health status.

Additionally, prolonged application of the tourniquet can cause discomfort and, in some cases, damage to the underlying tissue or veins, which may result in bruising or other complications. For these reasons, adhering to the 60-second guideline is crucial in clinical practice to ensure both patient safety and the integrity of the blood samples being collected.