Qualitative Assessment of Platelet/BLEEDING TIME Flashcards
- Included in the laboratory examination of primary hemostasis
- Done when a patient has normal platelet count (NV: 150-400k/uL) but with bleeding risk/history
Qualitative Assessment of Platelet
Suggestive of bleeding history → assessment of Platelet function test is conducted
Platelet count
- Reflects the platelet function
- Provides an estimate of the integrity of the platelet plug
- Measures the interaction between capillaries and platelet
BLEEDING TIME (OBSOLETE)
T/F. In BLEEDING TIME (OBSOLETE), An infrequently performed in vivo measurement of platelet adhesion (vWF and GP1b) and aggregation (GP2b3a and active ionized calcium ions) on locally injured vascular sub-endothelium
True
T/F. BLEEDING TIME (OBSOLETE) is performed bedside along with clotting time (for post-surgical procedures)
False, BLEEDING TIME (OBSOLETE) Performed bedside along with clotting time (for pre-surgical procedures)
✓ Phlebotomist’s uses a lancet to make a SMALL, CONTROLLED puncture wound (earlobe or fingertip)
✓ Inaccurate because the puncture site and depth is not standardized
Duke’s Method
Less callous finger use in Duke’s Method?
Ring finger (side)
T/F. In Duke’s Method, Puncture site is blotted with filter paper every 30 seconds until the bleeding stopped
* No blood = Recorded time
* Do not wipe the first drop of blot
* Do not squeeze the finger during the procedure
True
Duke’s Method Reference Interval:
2 – 9 minutes (universally accepted)
✓ Modified and standardized method
✓ A calibrated spring-loaded lancet was triggered on the volar surface of the forearm a few inches distal to the antecubital crease
✓ Puncture site is blotted with filter paper every 30 seconds until the bleeding stopped.
Standardized/Modified Ivy Method
In Standardized/Modified Ivy Method, A blood pressure cuff is inflated to ___ mmHg
40
In Standardized/Modified Ivy Method, Lancet is calibrated to 3mm deep *controlled 2 puncture sites because it is prone to?
hematoma
Standardized/Modified Ivy Method Reference Interval:
2 – 9 minutes (universally accepted)
✓ Degree of clot retraction is directly proportional to the number of platelets and inversely proportional to the hematocrit and the level of fibrinogen
✓ Obsolete test
✓ Evaluates how well platelets keep the clot adhered to the sides of specimen tube
Clot retraction
In Clot retraction what type of specimen and tube top are used?
whole blood in red top tube
Examine the clot at 1, 2, 4, and 24 hours for clot retraction. What causes if the px does not respond properly?
hemophilia
In Clot retraction By 30 minutes: Clots starts to?
shrink
T/F. In Clot retraction, after clot forms, remaining 70-60% consist of serum and RBC ‘fall-out’ from clot?
False, After clot forms, remaining 40-60% consist of serum and RBC ‘fall-out’ from clot
Must have normal fibrinogen and hematocrit for test to be accurate
Clot retraction
Capillary Fragility Test was also known as
RUMPEL–LEEDE CAPILLARY FRAGILITY TEST OR TOURNIQUET TEST
The test is defined by the World Health Organization as one of the necessary requisites for diagnosis of dengue fever.
Capillary Fragility Test
T/F. In Capillary Fragility Test, A blood pressure cuff is applied and inflated to a point between the systolic and diastolic blood pressures for 5 minutes and then check for petechiae.
True
T/F. In Capillary Fragility Test, Do not count near the edges of torniquet, count above the site.
False, Do not count near the edges of torniquet, count below the site
Capillary Fragility Test
Petechiae:
Purpura:
Ecchymosis:
Capillary Fragility Test
Petechiae: <3mm
Purpura: 3mm-1cm;
Ecchymosis: >1cm
