| Bleeding time is a crude test of hemostasis.
It indicates how well platelets interact with blood
vessel walls to form blood clots. Bleeding time is used
most often to detect qualitative defects of 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.
There are several methods to perform the bleeding time
test:
- Ivy method: is the traditional
format for this test. In the Ivy method, a blood pressure
cuff is placed on the upper arm and inflated. A lancet
or scalpel blade is used to make a stab wound on the
underside of the forearm. The time from when the stab
wound is made until all bleeding has stopped is measured
and is called the bleeding time. Every 30 seconds,
filter paper or a paper towel is used to draw off
the blood. The test is finished when bleeding has
stopped completely.
- Template method: a template is
placed over the area to be stabbed and two incisions
are made in the forearm using the template as a location
guide.
- Duke method: a nick is made in
an ear lobe or a fingertip is pricked to cause bleeding.
A normal bleeding time for the Ivy method is less than
five minutes from the time of the stab until all bleeding
from the wound stops. Some texts extend the normal range
to eight minutes. Normal values for the template method
range up to eight minutes, while for the modified template
methods, up to 10 minutes is considered normal. Normal
for the Duke method is three minutes.
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