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→Buccal Mucosal Bleeding Time
===Buccal Mucosal Bleeding Time===
===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 bleeding may not be easily stopped.
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 bleeding may not be as easily stopped.
The buccal mucosal bleeding time (BMBT) is one of the only clinically available methods of measuring platelet
function. It is performed by use of a standardized bleeding device to make an incision in the buccal mucosa of the
upper lip. The duration of time between making the incision and the cessation of bleeding is measured. The upper
lip is kept turned up (usually by a gauze muzzle) through out the procedure and blood is gently absorbed away
from the incision without disturbing the clot. A normal BMBT is considered to be approximately 3 minutes and
greater than 5 minutes is considered prolonged.
Abnormalities in platelet function and significant thrombocytopenia (<50,000/microL) will cause prolongations in
the BMBT. Causes 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.
When a small slit is made in the skin, the hemostatic mechanisms necessary for coagulation are activated. Without the aid of external pressure, bleeding usually stops within 7 to 9 minutes.
When a small slit is made in the skin, the hemostatic mechanisms necessary for coagulation are activated. Without the aid of external pressure, bleeding usually stops within 7 to 9 minutes.