To find Bleeding time of a given subject By Duke Method :
Introduction:
Bleeding time (BT) is the time interval from oozing of blood after a cut or injury till arrest of bleeding. Usually, it is determined by Duke method using blotting paper or filter paper method. Its normal duration is 3 to 6 minutes. It is prolonged in purpura.
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 other 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.Here in Duke method is explained.
Duke method :
a nick is made in an ear lobe or a fingertip is pricked to cause bleeding.
Requirements:
Subject, cotton Alcohol, Filter paper, Stop watch, Lancet.
Procedure:
1. Wash your hands properly with soap and allow it to dry.
2. Sterilize the finger tip using rectified alcohol and allow to dry.
3. Make a sufficiently deep prick in ear lobe using a sterile lancet, so that blood comes out freely without squeezing.
4. Note the time (start the stop-watch) when bleeding starts.
5. Mop the blood by touching the ear lobe with a filter paper.
6. This is repeated every 15 seconds, each time using a fresh portion of the filter paper, till bleeding stops.
7. Note the time (stop the stop-watch).
8. It is seen that the blood stains on the filter paper get smaller to disappear finally when bleeding stops.
Precautions:
9. Syringe should be sterilized
10. Carefully take blood at 15 degree angle to avoid double puncturing.
11. Clean the laboratory after performing pratical procedure.
Observations and Figures:
The bleeding time of subject was found to be 60 secs
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