1. Clean the lobe of the ear or tip of a finger with alcohol
2. For ear—glass slide is placed behind the ear lobe
and held firmly in place. This provides a firm site for
3. Pierce the lobe of the ear by a firm stroke against the
glass slide (or pierce the finger-tip). Discard the glass
slide if ear lobe has been incised. Start the stop watch
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 on a fresh area. When bleeding
slows, the wound is touched gently with a fresh area
of the filter paper at 30 second intervals. When blood
no longer stains the filter paper, the watch is stopped
The normal range is up to 6 minutes. Between 6 and 10
minutes, the results are borderline. Over 10 minutes is
1. In children, heel should be used.
2. In suspected cases of a bleeding disorder, the bleeding
may not be controlled easily from the ear lobe hence,
fingertip puncture wounds are better.
3. The area to be punctured should not be congested.
4. The size and depth of the wound may vary if one does
not have a standardized technique.
5. If bleeding persists for more than 15 minutes it should
be stopped by placing a dry gauge sponges over the site
and applying finger pressure (the filter paper used to
collect the drops of blood can be dried and saved as a
(Preferred because of greater ease of standardization).
1. Cleanse the inner aspect of the forearm with spirit and
2. Place a blood pressure cuff on the upper arm, inflate
at 40 mm Hg, and maintain the same throughout the
3. Select an area on the forearm—Volar aspect which is
devoid of superficial veins. Stretch the skin laterally
between the thumb and forefinger and hold in a taut
4. Take a cork, through which a no. 11 surgical blade has
been inserted with the tip extending 3 mm beyond the
cork surface (both cork and blade should have been
sterilized before), the blade should be withdrawn from
the cork and autoclaved before being used again.
5. Hold the cork with the thumb and forefinger of the
free hand, and with the heel of the hand resting on
the patient’s arm, quickly make two skin punctures
(actually they are small incisions) in the selected area.
It is important that the surface of the cork meet the skin
to ensure a 3 mm deep incision. Holding the skin taut
prevents the test area from being depressed when the
6. Timing is begun as soon as the incisions are made and
7. Using the edge of a piece of a filter paper to collect the
blood, gently touch paper to the drop of blood, which
Clinical Hematology: Bleeding Disorders 275
forms over the wound every 30 seconds. Do not rub or
remove the clot. Do not touch the skin. Any disruption
of formed fibrin or clot will prolong the bleeding time.
8. The bleeding time is reported when no blood stain
is seen on the filter paper after a gentle touch. It is
reported in intervals of 30 seconds. One can measure
both wounds and average them, or take the reading of
the last one to stop bleeding.
Normal values are 1 to 6 minutes. More than 6 minutes
1. Results of duplicate tests performed on the same
individual should agree within 2 to 3 minutes at most.
2. Bleeding time is prolonged:
• When platelet count < 100,000/mm3
• In patients on aspirin therapy.
• In acquired fibrinogen disorders.
(If the platelets are young even in a thrombocytopenia
patient, the bleeding time may not be raised as young
platelets have enhanced hemostatic capabilities).
When platelet counts are low, one can calculate the
expected bleeding time with the following formula:
A bleeding time longer than that calculated from platelet
numbers alone, suggests defective platelet function in
addition to reduced number. It is also possible to detect
above-normal hemostatic capacity in cases in which
active young platelets comprise the entire population of
1. Bleeding time is prolonged when the level of platelets
is decreased or when the platelets are qualitatively
b. Platelet dysfunction syndromes
c. Decrease or abnormality in plasma factors such as
von Willebrand’s factor and fibrinogen
d. Abnormalities in walls of the small blood vessels—
2. Bleeding time can be either normal or prolonged
in von Willebrand’s disease. It will definitely be
prolonged if aspirin is administered prior to testing.
3. A single prolonged bleeding time does not prove the
existence of hemorrhagic disease because a larger
vessel may have been punctured. The puncture should
be done twice (on the contralateral side) and the
average of the bleeding times can be taken.
1. The normal range may vary when the puncture is not
2. Touching the incision during the test will break off any
fibrin particles and prolong the bleeding time.
3. Heavy alcohol consumption (as in alcoholics) may
cause bleeding time to be increased.
4. Prolonged bleeding time will result from the ingestion
of 10 g of aspirin up to 5 days before the test.
5. Other drugs that may cause the bleeding time to be
• Streptokinase—streptodornase
1. Explain the purpose and procedure of the test to
2. Warn patient not to consume aspirin for 5 days prior
3. Advise patient not to consume alcohol in any form.
Capillary Tube Method of Wright
Blood is collected in about a dozen capillary tubes from
a finger prick made after aseptic precautions. The tubes
are sealed with plasticine and immersed in water bath at
C. After 4 minutes, remove the first tube from the bath
and expel the blood in it with one end immersed in a dish
containing water. Repeat this every 30 seconds with the
other tubes till the blood is expelled in a worm clot and note
An alternative way of determining the end point is to
break the capillary tubes every 30 seconds until a clot is
seen between the two broken ends. By these methods, the
normal clotting time is 5 to 10 minutes at 37oC and longer
if performed at room temperature. This test should be
avoided as tissue thromboplastin contaminates the oozing
blood and hence, false reports may be obtained.
Principle: Whole blood, when removed from the vascular
system and exposed to a foreign surface, will form a solid
the solid clot is a measure of the coagulation system.
2. Equipment for collection of blood
3. Clean, dry glass test tubes (10 × 75 mm)
1. Make a clean venipuncture with as little trauma to
(or time spent passing through) the connective tissue
between skin and vein as possible. One may routinely
or in selected cases use the two-syringe technique,
whereby one rinses the needle of all interstitial tissue
fluid by drawing back 1 cc. of blood after entering the
vein. Then remove the first syringe from the needle
and quickly place on a second clean and dry syringe
and draw back blood for the test.
2. Timing is begun when the blood first enters the syringe.
The second syringe in the ‘Two-syringe’ technique.
3. Draw 3–5 mL of blood and withdraw the syringe and
needle. Disconnect the needle. Place approximately
1 mL of blood in each of three (10 × 75 mm) test tubes.
4. Place the tubes in a stand so that they remain upright
and undisturbed, at room temperature for 10 minutes.
If a 37oC water bath is available one may do the entire
test at 37oC, and shorter clotting times will be found
(if the test has been done at 37oC, do not wait for more
5. After 10 minutes (or 5 minutes) take the first of the
tubes and gently tip it every 30 seconds to test for
clotting. Do not tip it further than necessary to get the
6. When the first tube is clotted (can be inverted without
blood running down the edge of the tube), record the
time and start the tipping of the second tube every 30
seconds until it is also found to be clotted. Then do
the same with the third tube (tipping is intended to
allow one to ascertain when blood is clotted—not as
a means of hastening clotting or of assuring mixing of
7. The time recorded for the clotting of the third tube is
taken as the clotting time (the purpose of the first two
tubes is to tell one when to start looking in the third
tube, since the agitation of tipping does hasten the
Some choose to tip the tubes in rotation (at 37oC) every
15 seconds, or tip all tubes at once, and average the
Normal times depend on method used. Normal range
at 37oC is usually 5 to 10 minutes. Normal times at room
temperature will vary with the degree of temperature
present and the method used. If one uses the method
which waits 10 minutes before starting to tip, then normal
values may go as high as 22 to 25 minutes, especially in
the cool season. Values shorter than 10 minutes should
be suspected and the test repeated using the two-syringe
technique to rule out contamination by tissue fluid (in the
heat of April, May or June warm tropical climate blood will
clot before 10 minutes without having been contaminated
by tissue fluids). If one uses the method which waits 5
minutes before tipping begins, normal results are between
8 to 18 minutes. Longer than 20 minutes is abnormal. If
clotting occurs in less than 7 minutes, the test should be
repeated using two-syringe technique.
1. The venipuncture must be without trauma to avoid
contamination with tissue thromboplastin.
2. If all three tubes are clotted at 10 minutes (or 5
minutes) when one starts to tip the first tube, the test
is unsatisfactory and should be repeated. If blood was
drawn by single syringe technique, the most likely
explanation is contamination, of the blood by tissue
thromboplastin. If a two-syringe technique is used, it
suggests that the patient’s blood is hypercoagulable.
3. Vigorous agitation of the tubes will significantly
shorten the coagulation time. So tipping should really
be very gentle just to see if the blood has clotted.
1. Severe deficiencies of any of the coagulation factors
must be present before the coagulation time will
be prolonged. Fibrinogen for example, needs to
be decreased to 50 mg/100 mL or less before the
coagulation time is affected, the normal range of
fibrinogen is 200 to 400 mg/100 mL.
2. When prothrombin is diminished to a level of 30% of
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