When collecting blood, when should the technician release the tourniquet?

The appropriate time to release the tourniquet during blood collection is after the collection is complete. This practice is crucial for several reasons.

Releasing the tourniquet immediately after the last sample tube is filled allows for normal blood flow to resume, which helps reduce discomfort for the patient. Keeping the tourniquet on longer than necessary can lead to a range of issues, such as hemoconcentration, where the concentration of cells and proteins increases due to the restriction of blood flow. This can potentially affect lab results, leading to inaccurate readings and unnecessary complications in diagnosis or treatment.

While the technician may feel tempted to release the tourniquet while the last tube is filling, doing so can lead to an incomplete collection or inadequate sample volume. Timing the release after the entire process ensures that the technician can properly manage the blood flow and collection process, thereby optimizing the quality of specimens sent to the lab for analysis.

Releasing the tourniquet within a specific timeframe, such as 1 minute or 2 to 3 minutes, can also be detrimental, as it does not align with the best practice of ensuring completion of the blood draw before alleviating the pressure, which can prevent complications and ensure accurate test results.