Assessment of Haemostasis

ASSESSMENT OF PRIMARY HEMOSTASIS 1.BLEEDING TIME Bleeding time is used to measure the duration of bleeding after a measured skin incision. Bleeding time may be measured by one of three methods: template, Ivy, or Duke. The template method is the most commonly used and the most accurate because the incision size is standardized. Bleeding time depends on the elasticity of the blood vessel wall and on the number and functional capacity of platelets. Although this test is usually performed on patients with a personal or family history of bleeding disorders, it's also useful- along with a platelet count for preoperative screening.The test is usually not recommended for patients with a platelet count of less than 75,000/u1. Purpose • To assess overall hemostatic function (platelet response to injury and functional capacity of vasoconstriction). • To detect congenital and acquired platelet function disorders. Bleeding time is used most often to detect qualitative defects of platelets, such as Von Willebrand's disease. The test helps identify people who have defects in their platelet function. This is the ability of blood to clot following a wound or trauma. Normally, platelets interact with the walls of blood vessels to cause a blood clot. There are many factors in the clotting mechanism, and they are initiated by platelets. The bleeding time test is usually used on patients who have a history of prolonged bleeding after cuts, or who have a family history of bleeding disorders. Also, the bleeding time test is sometimes performed as a preoperative test to determine a patient's likely bleeding response during and after surgery. However, in patients with no history of bleeding problems, or who are not taking anti-inflammatory drugs, the bleeding time test is not usually necessary. Precautions Before administering the test, patients should be questioned about what medications they may be taking. Some medications will adversely affect the