How should a phlebotomist respond if a vein collapses during a blood draw?

When a vein collapses during a blood draw, it is essential for the phlebotomist to take immediate steps to manage the situation effectively. Releasing the tourniquet and adjusting the needle can allow blood flow to return as it alleviates pressure on the vein, which may help in reestablishing access for blood collection. By slightly adjusting the needle's position, the phlebotomist can potentially reposition it to enter the vein again without having to change sites.

Using a larger needle is typically not appropriate in cases of vein collapse, as it may cause further damage or discomfort and does not address the underlying issue of the collapsed vein. Continuing to collect blood from the same site can cause additional complications and may lead to further collapse. Simply informing the patient and ending the draw may be necessary if the vein cannot be successfully accessed again, but it is often more effective to try to adjust the needle first to prevent the need for a new puncture site.