Changes

To perform the BMBT test, a standardised tool producing a uniform incision is used^{2, 3} 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 measured² 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 prolonged².

To perform the BMBT test, a standardised tool producing a uniform incision is used^{2, 3} 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 measured² 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 prolonged².

The BMBT is influenced by all the aspects of this phase, including vasoconstriction, platelet adherence and plately aggregation. Although this makes BMBT an effective screening test for the vascular/platelet (primary) phase of haemostasis, it also means it is not purely a test for thrombocytopathia, as it is often considered: BMBT depends on an intact vasospastic response and adequate platelet numbers as well as platelet function³.

Acquired platelet function abnormalities are often drug induced, for example by non-steroidal anti-inflammatory drugs<sup.2, 3</sup>, or caused by uraemia. Hereditary defects in platelet function also exist, and von Willebrand's disease is the most common of these.

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.

The BMBT is influenced by all the aspects of this phase, including vasoconstriction, platelet adherence and plately aggregation. Although this makes BMBT an effective screening test for the vascular/platelet (primary) phase of haemostasis, it also means it is not purely a test for thrombocytopathia, as it is often considered: BMBT depends on an intact vasospastic response and adequate platelet numbers as well as platelet function³. BMBT is also a fairly crude test, and has been found to be

 

normal in some patients with a known platelet function disorder and vice versa³. Therefore, the results of this test should be interpreted with some caution.

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==