(M) Lesson 5: Platelet Count and Function Test (Part 1)

Question 1

Platelet counts are important in helping diagnosing what type of disorders?

Answer 1

Bleeding

Question 2

Relative platelet count provides what in the peripheral blood?

Answer 2

Estimate number of platelets

Question 3

Platelets are counted under what objective?

Answer 3

OIO

Question 4

What is the normal value of platelets?

Answer 4

150,000 to 400,000

Some books say 450,000

Question 5

How many fields should be counted for platelets under OIO?

Answer 5

10 fields

Question 6

T or F: Platelets are the same regardless of age group.

Answer 6

False

In newborns, platelets are higher/elevated.

Question 7

How do we differentiate platelets from debris?

Clue: The unique characteristic of platelets.

Answer 7

Platelets are granulated.

Question 8

When there is a deficiency of dense granules, platelets appear as?

Answer 8

Pale or gray

Question 9

Four (4) reagents/equipment needed for platelet count

Answer 9

1. Glass slides
2. Wright Stain
3. Microscope
4. EDTA (Blood sample)

Question 10

Reagents and Equipment

What are the two (2) methods that may be used in staining?

Answer 10

1. Quick Staining Method (Dipping)
2. Rack Method (Flooding)

Question 11

Reagents and Equipment

T or F: Capillary blood may be used for platelet count in place of venous blood.

Answer 11

T

However, it is not preferred since it has interstitial fluid and must also be free-flowing.

Question 12

What are the two (2) types of specimen that may be used for platelet count?

Answer 12

1. Whole Blood (venous)
2. Blood from heel or fingertip (capillary)

When using capillary blood, you have to wipe away the first drop of blood.

Question 13

Platelet aggregation may be caused by what?

Answer 13

Traumatic venipuncture

Question 14

Platelet aggregation caused by traumatic venipuncture causes (falsely decreased/falsely increased) platelet count.

Answer 14

Falsely decreased

Question 15

Falsely decreased platelet count may be indicative of what two (2) phenomena?

Answer 15

1. Pseudothrombopenia
2. Pseudoleukocytosis

Question 16

This phenomena happens when EDTA is used in place of citrate in platelet count procedures.

Clue: causes platelets to bind with WBCs (e.g. neutrophils)

Answer 16

Platelet satellitosis

Question 17

Platelet satellitosis may also be caused by non-immunologic factors such as?

Two answers.

Answer 17

1. Thrombospondin
2. Alpha Granule Proteins

Question 18

What is the remedy for difficulties such as platelet aggregation and platelet sattelitosis?

Answer 18

1. Redraw with citrate
2. Perform manual count
3. Multiply by 1.1

Question 19

FIll in the blanks.

1. Prepare a ____ and stain it with routine hematological stain.
2. Place the prepared slides under the microscope and focus the ____ portion of the smear using the ____ objective.
3. Using the ____ method on moving the slide while focused, observe ____ fields and count the total number of platelets seen.
4. Get the average platelet per field by dividing the ____ of platelets counted with 10.
5. Calculate the relative platelet count using the formula (____)

Answer 19

1. Prepare a blood smear and stain it with routine hematological stain.
2. Place the prepared slides under the microscope and focus the thin portion of the smear using the oil immersion objective.
3. Using the battlement method on moving the slide while focused, observe 10 fields and count the total number of platelets seen.
4. Get the average platelet per field by dividing the total number of platelets counted with 10.
5. Calculate the relative platelet count using the formula (Relative Platelet Count = Average platelet per field x 20,000)

Question 20

What are the three (3) different methods in observing fields under the microscope?

Answer 20

1. Battlement Method
2. Longitudinal Method (Head to Tail)
3. Cross-Sectional Method (Edges)

Question 21

Which part of the blood smear do we count on?

Answer 21

Monolayer

Question 22

Match the following.

1. 0 to 49,000/uL
2. 50,000 to 99,000/uL
3. 100,000 to 149,000/uL
4. 150,000 to 199,000/uL
5. 200,000 to 400,000/uL
6. 401,000 to 599,000/uL
7. 600,000 to 800,000/uL
8. Above 800,000/uL

A. Normal
B. Slightly Decreased
C. Moderately Decreased
D. Low Normal
E. Moderately Increased
F. Slightly Increased
G. Marked Increase
H. Marked Decrease

Answer 22

1. H
2. C
3. B
4. D
5. A
6. F
7. E
8. G

Question 23

Match the following.

1. 3 to 10 platelets
2. 8 to 20 platelets

A. Per 100 RBC observed
B. Per 150 RBC observed
C. Per 200 RBC observed

Answer 23

1. A
2. C

Question 24

What is the manner of reporting for semi-quantitative platelet estimate?

Answer 24

Increase, adequate, or decrease

Question 25

What are the two (2) methods in manual absolute platelet counting?

Answer 25

1. Rees and Ecker Method 2. Unopette System

Question 26

# Unopette or Rees and Ecker **Blood Used:** EDTA anticoagulated blood

Answer 26

Both

Question 27

# Unopette or Rees and Ecker * **Diluting Fluid Used:** Brilliant Cresyl Blue + Formalin + Distilled H2O + Citrate

Answer 27

Rees and Ecker | **Note:** Those are components of the Rees and Ecker diluting fluid.

Question 28

# Unopette or Rees and Ecker * **Diluting Fluid Used:** Ammonium Oxalate

Answer 28

Unopette System

Question 29

# Unopette or Rees and Ecker * **Pipette Used:** Either WBC or RBC pipette

Answer 29

Rees and Ecker

Question 30

# Unopette or Rees and Ecker * **Pipette Used:** Unopette System | Teh, ewan ko na lang talaga pag nagkamali ka.

Answer 30

Unopette System

Question 31

# Unopette or Rees and Ecker * **Dilution Made:** 1:100, 1:20, 1:200

Answer 31

Rees and Ecker

Question 32

# Unopette or Rees and Ecker * **Dilution Made:** 1:100

Answer 32

Unopette System

Question 33

# Unopette or Rees and Ecker * **Square Used:** Either WBC or RBC squares

Answer 33

Rees and Ecker

Question 34

# Unopette or Rees and Ecker * **Square Used:** RBC square

Answer 34

Unopette System

Question 35

This specific absolute platelet counting method is what is common in hospitals and is sold by the kit.

Answer 35

Unopette System

Question 36

Aralin niyo na lang yung procedures ng Rees and Ecker, mwa.

Answer 36

Go niyo na.

Question 37

What is the purpose of the wet filter paper in the petri dish?

Answer 37

To prevent evaporation

Question 38

* Reference method for platelet counting * Uses a **phase contrast microscope** * Uses **ammonium oxalate** as a diluting fluid

Answer 38

Brecher-Cronkite Method

Question 39

The tourniquet should be placed ____ inches or ____ cm above the site of puncture.

Answer 39

3 to 4 inches or 7.5 to 10 cm

Question 40

If a touriniquet is unavailable, a BP cuff may be used set to how much pressure?

Answer 40

40 to 60 mmHg

Question 41

What is more clinically significant: prolonged or shortened bleeding time?

Answer 41

Prolonged

Question 42

* The tourniquet should be released within ____ * It should also be released as soon as ____

Answer 42

* Should be released **within 1 minute** and as soon as **the vein is entered**

Question 43

This needle gauge is most commonly used in venipuncture.

Answer 43

21 gauge (green)

Question 44

Why is plastic or silicone-coated syringe preferred over glass syringes?

Answer 44

Because platelets have clotting factors that activate upon contact with glass

Question 45

* The choice of coagulant for coagulation studies * Has **two formulations:** 3.2% (0.109 M) and 3.8% (0.129 M) * Preserves the labile clotting factors * Satisfactory for platelet aggregation studies * **Ratio of AC to Blood:** 1:9

Answer 45

Citrate

Question 46

# Match the following. 1. Inhibits the fibrinogen-thrombin reaction 2. Factor V is not stable in its presence 3. Inactivates thrombin A. EDTA B. Heparin

Answer 46

1. A 2. A 3. B

Question 47

What are the two (2) methods in extracting blood for platelet counting?

Answer 47

1. Syringe Method 2. ETS Method

Question 48

This is the **preferred** method of collection of blood for platelet counting.

Answer 48

ETS method

Question 49

Please read the procedures na lang for blood collection. Alam niyo na yan, malaki na kayo. 😘

Answer 49

Go niyo na, mwa.

Question 50

What three (3) changes occur in the sample for platelet counting?

Answer 50

1. Effect of pH 2. Effect of temperature 3. Centrifugation

Question 51

# Effect of pH * If testing is **not done immediately,** samples should remain?

Answer 51

Unopened

Question 52

# Effect of pH Platelets are stable for ____, meaning there will be **no changes in PT or APTT results.**

Answer 52

6 hours

Question 53

# Effect of Temperature * ____ and ____ are likely to deteriorate.

Answer 53

Factor V and VIII

Question 54

# Effect of Temperature * ____ and ____ will be **prematurely activated** at ref temperature (1 to 6 deg Celsius)

Answer 54

Factor VII and XI

Question 55

# Effect of Temperature * Samples should **not be frozen** if testing can be done within ___

Answer 55

Within 2 hours after collection

Question 56

Please memorize the hemostasis specimen storage times and temperature.

Answer 56

Thanks, lods.

Question 57

# Centrifugation What type of plasma is required for platelet counting?

Answer 57

Platelet-free plasma

Question 58

T or F: Hemolysis should be avoided.

Answer 58

T

Question 59

# PRP or PPP? * Sample is centrifuged at 60 to 100 x g for 10 minutes at room temperature * Plasma is removed immediately with a plastic or siliconized pipette * For **platelet aggregation studies**

Answer 59

PRP

Question 60

# PRP or PPP? * Applicable for **coagulation studies** * Recentrifuging the sample remaining from the PRP at 2000 x g for 10 minutes

Answer 60

PPP

Question 61

What are the six (6) technical errors that may cause hemolysis?

Answer 61

1. Needles with **too small bore** 2. **Frothing of sample** due to entry of air 3. **Excessive stasis** through prolonged applicaion of the tourniquet 4. Expelling blood from the syringe **through the needle** 5. **Moisture or contamination** in the needle, syringe, or blood container 6. **Excessive and vigorous mixing** of blood with the anticoagulant

Question 62

Please study the hemostasis specimen collection and management that require specimen rejection.

Answer 62

Last na yan, gaur.