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 
الأربعاء 4 أغسطس - 12:48
