When the platelet count and the blood film examination are normal, the bleeding time is performed to detect abnormal platelet function. The test measures platelet plug formation in vivo. Bleeding stops within 3 to 8 minutes and there is a progressive prolongation with platelet counts less than 75 x 109/l. A prolonged bleeding time is also found in patients with disorders of platelet function. The time-consuming and skill-intensive platelet aggregation studies may be of help in delineating platelet functional defects. In recent years, other less labour-intensive methods may speedily provide objective information on platelet function have become available. These include PFA-100 (platelet function analyser-100). The PFA-100 can be performed on whole blood, and would readily provide the necessary information on platelet competence.21
Was this article helpful?