Final answer:
During a routine venipuncture, the phlebotomist should request that the patient 'release the fist' when the last tube has been filled, before the tourniquet is removed.
Step-by-step explanation:
During a routine venipuncture, the phlebotomist should request that the patient 'release the fist' when the last tube has been filled, before the tourniquet is removed. This is important because releasing the fist before removing the tourniquet helps prevent excessive bleeding and minimizes the risk of hematoma formation. Once the tourniquet is removed, the phlebotomist should apply pressure to the puncture site to stop any bleeding.