Determination of Bleeding Time and Clotting Time Bleeding: means loss of blood from damaged or injured small vessels. Bleeding time: is the time interval from oozing of blood after a cut or injury till arrest of bleeding. Clotting: is the process or mechanism of preventing blood loss through the injured vessel.

1. Determination of Bleeding
Time and Clotting Time

2. Determination of Bleeding Time and
Clotting Time
Bleeding: means loss of blood from damaged or
injured small vessels.
Bleeding time: is the time interval from oozing of
blood after a cut or injury till arrest of bleeding.
Clotting: is the process or mechanism of prevention
the blood loss through the injured vessel.

3. Bleeding and Clotting Time

4. This process has three main steps
 1-contraction of blood vessel: contraction of the smooth
muscles in the wall of the blood vessel, this reduce the
blood flow and loss from the defect in the vessel wall.
 2-Aggregation of platelets: Activated platelets become
sticky and adhere to the defect to form temporary platelet
plug due to bind of platelets to collagen tissue.
 3- Formation of blood clot.

6. Clotting Time
 Clotting Time -
: The time required for blood
to form a clot.
 The normal range of clotting time in glass
tubes is 5 to 15 minutes.

7. Clotting Time
 The clotting time will be prolonged if the
volume of blood per tube or the diameter of
the tube is increased, or if the temperature
decreased.

8. Clotting Time

10. Capillary tube method
Procedure:
1-Prick a finger with a sterile lancet, fill 2 non
heparinzed capillary tube with blood (capillary
tube should touch the bleeding point), wipe
any excess blood from the outside of the tube.
2- Wait for 4 minutes, then cut the tube after
each 30 seconds.
3- Note the time if the fibrin thread is formed
between the 2 broken capillary tubes.

11. Clotting time of whole blood

12. Bleeding Time

13. Bleeding Time
 The time it takes for bleeding to stop (i.e. the time
it takes for a platelet plug to form) is measured.
 Normal bleeding time is 3 -6 minutes.
 Estimation of bleeding time is not a reliable test,
because the results at this test would vary
depending on the site and depth of puncture.

14. Bleeding Time
 More ever it is short timed during cold weather
due to capillary construction, and reverse case
in hot weather.
 A prolonged bleeding time may be a result
from decreased number of thrombocytes or
impaired blood vessels.

15. Bleeding Time
Bleeding time is a test of platelet function.

16.  Clinical Application Bleeding time is
prolonged in the following conditions:
 Platelet dysfunction.
 Blood vessel wall disorders.
 Haemophilia.
 Von Willebrand Disease.
 Thrombocytopenia.
 Vitamin K deficiency.
 Use of these medications as well prolong
bleeding time :
Aspirin and heparin.

17. Dukeś method
Procedure:
 Clean fingertip or earlobe with spirit and with sterile
lancet give at least 2 mm deep prick.
 Note the time.
 Every 30 second blot off the drop of blood by filter
paper until no more blood appear on the puncture
site, note the time at which the bleeding has stopped.

18. Bleeding time
Every 30 sec.
-