How long should a tourniquet be applied to avoid complications?

Applying a tourniquet is an essential step in the venipuncture process as it helps to engorge the veins, making them more prominent and easier to access. However, the duration for which the tourniquet is applied is crucial to avoid complications such as hemoconcentration, which can affect test results and lead to patient discomfort.

The correct duration for applying a tourniquet is no longer than one minute. This time frame minimizes the risk of complications like the pooling of blood and the alteration of plasma components. If the tourniquet is left on for too long—more than a minute—arterial blood flow may become compromised, increasing potassium and protein concentrations in the blood sample, which in turn could lead to erroneous laboratory results.

Using a tourniquet for more than one minute can also lead to unnecessary pain and discomfort for the patient. Therefore, it is vital to limit the application time to under one minute to ensure both the integrity of the sample collected and the comfort of the patient.