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Bleeding Time
Bleeding Time
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Bleeding Time
Category: Hemostasis.
Subcategory: Platelet-activity tests.
Material studied: Blood.
Estimated cost of test: $19.00.
Patient time for test: 30 minutes.
Reliability of test results: Good.
Available as home self-test? No.
Note: Bleeding time is measured by one of four methods -- Duke, Ivy, template or modified template.
BEFORE THE TEST
Purpose of test:
Assesses overall platelet response to injury.
Assesses functional capacity of vasoconstriction*.
Detects congenital and acquired blood disorders.
Where is test performed?
Commercial laboratory, hospital, doctor's office.
Who performs test?
Lab technician, nurse, doctor.
Risks and precautions:
If bleeding doesn't stop in 15 minutes, the test is discontinued.
Incisions leave two small, hairline scars that are barely visible when healed.
If blood-pressure cuff is applied on the arm too long (over 1 minute), it may cause an inaccurate test result. Request another sample to be collected to ensure accuracy.
Patient preparation:
Activity--No changes necessary.
Diet--Do not drink any alcohol for at least 24 hours before test.
Medicines--Inform the person performing the test if you have recently taken any medications listed under Taking these drugs may affect test results. You may be asked not to take this medication before the test.
Disrobing--None required. Roll up sleeve only.
THE TEST
Sensory factors:
Touching--You will feel mild discomfort when the needle is inserted into the vein or when the lancet pricks a finger, heel or ear lobe.
Seeing--You will see the technician, nurse or doctor, the basket or tray to hold the equipment, the needles, syringes, collecting tubes and bandages.
Feeling--Some degree of apprehension or fear is normal and should be expected. Discomfort disappears when the test is finished.
Other senses (taste, smell, hearing)--Not affected.
Equipment used:
Needles, syringes and heparinized* collecting tubes. Sterile, disposable equipment prevents contamination or spread of infection. There is no risk of becoming infected with the hepatitis virus, AIDS virus or any other infecting germ.
Description of tests:
Duke:
Small incisions are made in the ear lobe with a disposable lancet.
Operator blots the site every 30 seconds and measures the time until bleeding stops.
Ivy:
Operator wraps blood-pressure cuff around upper arm and inflates it to 40.
Three small punctures are made in the lower arm with a disposable lancet.
Operator blots the site every 30 seconds and measures (with a stopwatch) the bleeding time of each.
The average of the three is reported.
Template and Modified Template:
Operator wraps blood-pressure cuff around upper arm and inflates it to 40.
Template is applied to the arm to make two incisions.
Modified-template method uses a spring-loaded blade to make two incisions.
Operator blots the site every 30 seconds and measures the time until bleeding stops.
AFTER THE TEST
Immediate post-test care:
Apply pressure to the puncture site for 5 minutes.
Activity after test:
If you have a bleeding tendency, such as hemophilia*, keep a pressure bandage over the incision for 24 to 48 hours to prevent further bleeding.
If you do not have a bleeding tendency, a piece of gauze with a bandage should be sufficient. Check the incision site frequently.
Resume taking any medications that were withheld before the test.
Time before test results available: Up to 30 minutes.
TEST RESULTS
Test values:
Bleeding time depends on the elasticity of the blood-vessel wall and on the number and functional capacity of platelets.
Normal values:
Ivy method--Bleeding time is 1 to 7 minutes.
Duke method--Bleeding time is 1 to 3 minutes.
Template method--Bleeding time is 2 to 8 minutes.
Modified template method--Bleeding time is 2 to 10 minutes.
What ABNORMAL may indicate:
Hodgkin's disease*.
Acute leukemia*.
Disseminated intravascular coagulation.
Hemolytic disease* of the newborn.
Purpura*.
Liver disease.
Blood-factor deficiency*.
Taking these drugs may affect test results:
Acetylsalicylic acid.
Anti-coagulants.
Anti-neoplastics.
Aspirin and aspirin compounds.
Dextran.
Non-narcotic analgesics.
Non-steroidal anti-inflammatory drugs.
Pantothenyl alcohol and derivatives.
Streptokinase-streptodornase.
Sulfonamides.
Thiazides.
Other factors that may affect test results: None expected.
*See Glossary.
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