Bleeding time tests
Duke's method:
1- Clean the lobe of ear or tip of finger with alcohol and let it dray .
2-for ear glass slid is placed behind the ear lobe and hold firmly in
place, this provides a firm site for incision .
3-Pierce the lobe for the ear by a firm stroke against the glass slide
if the ear lobe has been increased , start the stop watch when the stab
was made.
4-Bleeding of the wound should be allowed to proceed without pressure
and the blood is allowed to drop on the filter paper .the paper should
be moved so that each drop will fall an afresh area , when blood slows ,
the wound is touched gently with a fresh area of the filter paper at 30
sec. intervals.
When blood no longer stains the filter paper ,the watch is stopped and
the time record.
Normal values = up to 6 min.
Over 10 min. is definitely abnormal.
Precaution:
-in children heel should be used .
-in suspected cases of bleeding disorder the bleeding may not be
controlled easily from the ear lobe lance fingertip puncture are better .
-the area to be punctured should not be congested .
-the size and depth of the wound may vary if one does not have a
standardized technique .
-if the bleeding persists for more than 15 min it should be stopped by
placing a dray gauze and applying finger pressure .
Ivy's method :-
1-Clean the inner aspect of the forearm .
2-Place a blood pressure cuff on the upper arm , inflate at 40 mm/Hg and
maintain the same throughout the test.
3-Select an area on the forearm velar aspect with is devoid of
superficial veins . stretch the skin laterally between the thumb and
forefinger and hold in a taut position.
4-Using a lancet a skin puncture is made on ventral surface of the arm
(3mm incision ).
5-With filter paper the blood is gently blotted until bleeding ceases.
Normal values : 2½ min. to 7 min.
Clotting time test :
Capillary tube method of Wright :
Blood is collected in capillary tubes about 12 tubes from a finger prick
made after aseptic precaution , the tubes are sealed with plasticine
and immersed in water bath at 37cº . after 4 min. remove the
first tube from the bath and expel the blood in it with one end immersed
in dish containing water . Repeat this every 30 sec. with the other
tubes till the blood is expelled in warm clot and note the time .
* an alternative way determining the end point is to break the capillary
tubes every 30 sec. until clot is seen between the two broken ends by
these methods normal clotting time is 5-10 min. at 37cº.
Lee and White's method
1-Make a clean vein puncture with as little trauma to the connection
tissue between skin and vein as possible.
2-Timing is begun when the blood first enters the syringe.
3-Drow 3-5 ml of blood and withdraw the syringe and the needle ,
disconnect the needle , place approximately 1 ml of blood in each of
3test tubes.
4-Place the tubes in a stand and put them in water bath at
37cº. wait for 5 min. (if in room temp. wait for 10 min. )
5-take the first tubes and gently tip it every 30 sec. to test for
clotting , after every 30 sec. check another tube for clotting .
6-Record the clotting time for each tube , sum all the times and divided
by three .
Normal at 37cº = 5-10 min.
موضوع: BT & CT 
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