Qualitative Assessment of Platelet/BLEEDING TIME

Question 1

• 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

Answer 1

Qualitative Assessment of Platelet

Question 2

Suggestive of bleeding history → assessment of Platelet function test is conducted

Answer 2

Platelet count

Question 3

• Reflects the platelet function
• Provides an estimate of the integrity of the platelet plug
• Measures the interaction between capillaries and platelet

Answer 3

BLEEDING TIME (OBSOLETE)

Question 4

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

Answer 4

True

Question 5

T/F. BLEEDING TIME (OBSOLETE) is performed bedside along with clotting time (for post-surgical procedures)

Answer 5

False, BLEEDING TIME (OBSOLETE) Performed bedside along with clotting time (for pre-surgical procedures)

Question 6

✓ 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

Answer 6

Duke’s Method

Question 7

Less callous finger use in Duke’s Method?

Answer 7

Ring finger (side)

Question 8

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

Answer 8

True

Question 9

Duke’s Method Reference Interval:

Answer 9

2 – 9 minutes (universally accepted)

Question 10

✓ 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.

Answer 10

Standardized/Modified Ivy Method

Question 11

In Standardized/Modified Ivy Method, A blood pressure cuff is inflated to ___ mmHg

Answer 11

40

Question 12

In Standardized/Modified Ivy Method, Lancet is calibrated to 3mm deep *controlled 2 puncture sites because it is prone to?

Answer 12

hematoma

Question 13

Standardized/Modified Ivy Method Reference Interval:

Answer 13

2 – 9 minutes (universally accepted)

Question 14

✓ 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

Answer 14

Clot retraction

Question 15

In Clot retraction what type of specimen and tube top are used?

Answer 15

whole blood in red top tube

Question 16

Examine the clot at 1, 2, 4, and 24 hours for clot retraction. What causes if the px does not respond properly?

Answer 16

hemophilia

Question 17

In Clot retraction By 30 minutes: Clots starts to?

Answer 17

shrink

Question 18

T/F. In Clot retraction, after clot forms, remaining 70-60% consist of serum and RBC ‘fall-out’ from clot?

Answer 18

False, After clot forms, remaining 40-60% consist of serum and RBC ‘fall-out’ from clot

Question 19

Must have normal fibrinogen and hematocrit for test to be accurate

Answer 19

Clot retraction

Question 20

Capillary Fragility Test was also known as

Answer 20

RUMPEL–LEEDE CAPILLARY FRAGILITY TEST OR TOURNIQUET TEST

Question 21

The test is defined by the World Health Organization as one of the necessary requisites for diagnosis of dengue fever.

Answer 21

Capillary Fragility Test

Question 22

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.

Answer 22

True

Question 23

T/F. In Capillary Fragility Test, Do not count near the edges of torniquet, count above the site.

Answer 23

False, Do not count near the edges of torniquet, count below the site

Question 24

Capillary Fragility Test
Petechiae:
Purpura:
Ecchymosis:

Answer 24

Capillary Fragility Test
Petechiae: <3mm
Purpura: 3mm-1cm;
Ecchymosis: >1cm

Question 25

If 10 or more petechiae per square inch

Answer 25

POSITIVE

Question 26

If 20 or more petechiae per square inch

Answer 26

DENGUE HEMORRHAGIC FEVER

Question 27

Does not have high specificity since it is only a SCREENING TEST

Answer 27

Capillary Fragility Test

Question 28

Steps in Tourniquet Test (CDC Procedure)

Answer 28

1. Take the patient’s blood pressure and record it, for example, 100/70.
2. Inflate the cuff to a point midway between SBP and DBP and maintain for minutes. (100 +70) ÷ 2 = 85 mm Hg
3. Reduce and wait 2 minutes
4. Count petechiae below antecubital fossa
5. A positive test is 10 or more petechiae per 1 square inch.