What are platelet clumps and how can I avoid them?
Platelet clumps are formed during phlebotomy, in storage in the EDTA tube, or during preparation of the blood smear. They represent the normal adhesion tendency of platelets and are “artifacts” in that they are not circulating in the patient s blood. The clumping becomes important in interpretation of platelet numbers. When the platelets are not evenly distributed in the sample, the platelet count may underestimate the platelet number. At Phoenix Laboratory, certified laboratory technicians evaluate a blood smear from every CBC to estimate platelet numbers and for the presence of platelet clumps. Platelet clumping can be minimized by getting a “clean stick” during phlebotomy, immediately putting the blood into the EDTA tube, and gently mixing the sample. Sometimes this is not enough to prevent platelet clumping. When blood from a patient repeatedly has too many platelet clumps to accurately assess platelet numbers, a blood sample can be drawn into a heparin flushed syringe before putti
