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→Buccal Mucosal Bleeding Time
The buccal mucosal bleeding time is a simple test that gives a rapid assessment of platelet function, providing platelet numbers are normal. If platelet numbers are below 50x10<sup>9</sup>/l, this test should not be performed since the results will be affected by thrombocytopenia, making them unreliable. The small wound inflicted may also not stop bleeding easily.
The buccal mucosal bleeding time is a simple test that gives a rapid assessment of platelet function, providing platelet numbers are normal. If platelet numbers are below 50x10<sup>9</sup>/l, this test should not be performed since the results will be affected by thrombocytopenia, making them unreliable. The small wound inflicted may also not stop bleeding easily.
To perform the BMBT test, a standardised device is used to make an incision in the buccal mucosa of the upper lip, and the time between making the incision and the cessation of bleeding is measured<sup>2</sup> During the procedure the lip should be kept turned outwards, with excess blood being gently absorbed without disturbing clot formation a away from the site of the incision. Normally, bleeding should stop within 3 minutes, and a BMBT of greater than 5 minutes is considered prolonged<sup>2</sup>. utes and
To perform the BMBT test, a standardised tool producing a uniform incision is used<sup>3</sup> to make an incision in the buccal mucosa of the upper lip, and the time between making the incision and the cessation of bleeding is measured<sup>2</sup> During the procedure the lip should be kept turned outwards, with excess blood being gently absorbed at a site away from the incision, without disturbing clot formation or applying pressure. Normally, bleeding should stop within 3 minutes, and a BMBT of greater than 5 minutes is considered prolonged<sup>2</sup>. utes and
greater than 5 minutes is considered prolonged.
greater than 5 minutes is considered prolonged.
The vascular platelet phase of hemostasis consists of a primary vasoconstriction that serves to decrease blood flow, followed by adherence of platelets to the ruptured endothelium (adhesion) and each other (aggregation). This platelet aggregate, called the platelet plug, stops the bleeding and forms a matrix for the clot. The bleeding time is an excellent screening test for the vascular platelet phase of hemostasis. It depends on an intact vasospastic response in a small vessel and an adequate number of functionally active platelets.
The vascular platelet phase of hemostasis consists of a primary vasoconstriction that serves to decrease blood flow, followed by adherence of platelets to the ruptured endothelium (adhesion) and each other (aggregation). This platelet aggregate, called the platelet plug, stops the bleeding and forms a matrix for the clot. The bleeding time is an excellent screening test for the vascular platelet phase of hemostasis. It depends on an intact vasospastic response in a small vessel and an adequate number of functionally active platelets.
Patients with abnormalities of the vascular platelet phase of hemostasis present with purpura (petechiae and ecchymoses) and spontaneous bruising. They may have mucosal bleeding and fundus hemorrhages. Commonly, the problem is either thrombocytopenia, easily evaluated by a platelet count, or abnormal platelet function, which can be diagnosed with platelet function studies. The most common acquired platelet function abnormalities are drug induced (aspirin and the nonsteroidal anti-inflammatory agents) and uremia. The most common hereditary abnormality is von Willebrand's disease.
Patients with abnormalities of the vascular platelet phase of hemostasis present with purpura (petechiae and ecchymoses) and spontaneous bruising. They may have mucosal bleeding and fundus hemorrhages. Commonly, the problem is either thrombocytopenia, easily evaluated by a platelet count, or abnormal platelet function, which can be diagnosed with platelet function studies. The most common acquired platelet function abnormalities are drug induced (aspirin and the nonsteroidal anti-inflammatory agents) and uremia. The most common hereditary abnormality is von Willebrand's disease.
auses of thrombocytopathia include uremia, non-steroidal drug therapy such as aspirin and von
Willebrands disease. Unfortunately the BMBT is a fairly crude test of platelet function and it has been found to be
normal in some patients with a known platelet function disorder and abnormal in patients with normal platelet
function. As such the results of this test should be interpreted with some caution.
==Tests Evaluating Secondary Haemostasis==
==Tests Evaluating Secondary Haemostasis==