HEMA LAB Flashcards
first response of the body following blood vessel injury.
Primary hemostasis
the main players in their stage to prevent undue loss of blood
latelets and the vascular responses
There are three stages involved in primary hemostasis and these are:
platelet adhesion, platelet activation and platelet aggregation
The interval required for the blood to stop flowing from a skin incision.
Bleeding time
It measures the ability of blood vessels to control bleeding injury by formation of platelet plug or hemostatic plug.
Bleeding time
METHOD FOR BLEEDING TIME
DUKE’S METHOD
MODIFIED IVY’S METHOD
COPLEY- LALITCH METHOD
The Lobe of the ear is the site of choice for puncture.
DUKE’S METHOD
Reference Range of Dukes method
2-4 minutes (however, normal persons may occasionally give up values up to 5 minutes
It is a standardized and the average of bleeding time from three separate incisions in the forearm is noted.
Capillary pressure
This provides a very accurate technique if the incisions are identical.
MODIFIED IVY’S METHOD
Placed around the patient’s upper arm in modified method
sphygomomanometer cuff
sphygomomanometer cuff pressure is raised to
40mmHg
Modified ivys method depth wound
3mm along flexor (inner) aspect of the forearm
The blood pressure cuff is will be
decompressed
interval before repeating the ivy’s method
5 minutes
COPLEY- LALITCH METHOD depth
6mm
COPLEY- LALITCH METHOD Reference Ranges
3 minute
MODIFIED IVY’S METHOD Reference Range
1/2 - 7
Prolonged bleeding time is seen: (10)
When the blood platelets are greatly reduced 2. Thrombocytopenic purpura
3. Acute Leukemia
4. Aplastic anemia
5. In injury to capillary wall
6. Scurvy ( deficiency of Vit. C)
7. Toxins (infection, chemical, snake venom)
8. Allergy
9. In prothrombin deficiency
10. Destructive disease of the liver with
hemorrhagic tendencies
When blood coagulation is complete, the clot normally undergoes
Retraction
expressed from the clot and the clot becomes denser
serum
In normal clot retraction requires a normal number of
Platelets
Calcium
ATP,
Fibrinogen and Fibrin.
An abnormal clot retraction time is found in
Glanzmann’s thrombasthenia and thrombocytopenia.
The formed clot will be small and there will be increased amounts of red blood cells expressed from the clot. (RBC fall out)
Dysfibrinogenemia/ Hypofibrinogenemia
Clot retraction may also be abnormal in? where the protein interferes with fibrin formation. In DIC, the formed clot will appear small and ragged, and increased RBC fall out.
Paraproteinemias
Anemia states, the reverse occurs and the degree of clot retraction is
Increase
METHODS OF CLOT RETRACTION (2)
Single Tube Method
Hirshboeck method/Castor Oil method
mL venous blood in a clean dry centrifuge tube.
5mL
Insert a coiled wire in the bottom of the tube
( ? mm thick, with a cm diameter coil)
1 mm
Incubate at 37 oc for ? hour after clotting has occurred.
1 hour
Gently lift the wire and allow the attached clot to drain for
2 minutes
Reference range of single tube method
44 – 67%
Color of serum that appears within the first hour. In 18- 24 hours, the volume varies from 40% to 57% of the total amount of blood.
Clear Pale Yellow
When the clot is defective ad incapable of proper retraction, the volume of serum is less than ?
40%
Serum may appear ? after meals or in diabetes and leukemia.
milky
It may be deep ? in hemolytic jaundice leukemia and in obstructive jaundice or in carotenemia.
Yellow
Puncture sterilized finger, wipe off first drop, suck 20 ml of blood in a
Salhi’s Pipette
Start the timing and observe for a visible dimpling or a ? on the surface of the drop of blood. Note the time. This indicates the end front of the test.
nipple-like protrusion
Clot retraction is reported ? if dimpling happens after 1 hour. Record the time.
delayed
Clinical Significance of Hirshboeck method
Platelet disorders (Glanzmann’s thrombasthenia) , Thrombocytopenia.
Also called the tourniquet test,
Capillary Fragility test
Is a clinical diagnostic method used to assess the fragility of the capillary walls.
Capillary Fragility
measures platelet’s ability to maintain capillary integrity.
capillary fragility
The capillary or resistance test can be done using the following methods:
Rumpel-Leede/Hess test positive pressure technique/Tourniquet test
Suction Cup/ Petechiometer Method/
Negative Pressure Technique
Appearance of few petechiae after the test indicates a positive test which indicates weakness of the capillary walls or capillary permeability and fragility.
Rumpel-Leede/Hess test positive pressure technique/Tourniquet test
Mark a definite area ( ? cm in a diameter) on the forearm.
5cm
The upper edge which is ?cm below the bend of the elbow.
4cm
Place a blood pressure cuff on the arm and raise the pressure to ? mmHg of mercury and leave it for 8 minutes.
80mmHg
Pin point hemorrhagic spots.
Petechiae
Hemorrhage of blood into small area of the skin.
Purpura
Blood escapes into a larger into the skin
Ecchymosis
Nose bleeding
Epistaxis
Leakage of blood into join cavities
Hemarthrosis
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Hematemesis
Swelling or tumor in the tissue, body cavities contain clotted blood
Hematoma
Blood in urine
Hematuria
Hemoglobin presence in urine
Hemoglobinuria
Reference Range of Tourniquet Test
1-10 Petechiae
The cup is applied to the outer surface of the arm for a period of one minute at 200 mmHg and the resistance of the capillaries is expressed as the negative pressure required to produce a macroscopic petechiae.
Suction Cup Technique
Noramal Value of Suction Cup Technique
less than 4 Petechiae
Clinical Significance of Suction Cup Technique
Increased in Purpura, Dengue Fever ad Scurvy
