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Hematology (S) > HEMA 1 (Hemostasis Test) > Flashcards

HEMA 1 (Hemostasis Test) Flashcards

1
Q

What are the factors to consider in hemostasis test?

A
  1. Temp
  2. Hemolysis
  3. Glass surface
  4. Tissue thromboplastin
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2
Q

What are the effects of temp in hemostasis?

A
  1. Room temp = labile factors (V, VIII) will deteriorate for an extended period of time
  2. Cold temp = activates factor VII and XI
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3
Q

What is the effect of hemolysis in hemostasis?

A

Hemolyzed RBCs act like tissue thromboplastin in activating plasma clotting factors

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4
Q

What are the effects of glass surface in hemostasis?

A
  1. The contact factors (HMWK, PK, XII, XI) will be activated prematurely by contact w/ glass
  2. Recommended materials are:
    a. Plastic
    b. Polystrene
    c. Silicone-coated glass
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5
Q

What is the effect of tissue thromboplastin in hemostasis?

A

Potent clot-activating substance found in fluids that escape from injured cells and tissue spaces

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6
Q

What are the technical errors that can cause hemolysis?

A
  1. Excessive stains through prolonged application of the tourniquet (> 1 min)
  2. Moisture / contamination in the needle, syringe, / bld container
  3. Using needle w/ too small a bore (20 G: most commonly used)
  4. Frothing of sx due to entry of air
  5. Expelling bld from the syringe through the needle
  6. Excessive and vigorous mixing of bld w/ the anticoagulant
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7
Q

What is the color of EDTA?

A

Lavender top

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8
Q

What are the fxns of EDTA?

A
  1. Prevents coagulation by chelating Ca
  2. For bld cell ct (RBC, WBC, PLT)
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9
Q

What is the bld to anticoagulant (B:AC) ratio of EDTA?

A

4:1

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10
Q

What is the color of 3.2% sodium citrate?

A

Light blue top

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11
Q

What are the fxns of 3.2% Na citrate?

A
  1. For coagulation test
  2. Preserves the labile clotting factors V and VIII better
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12
Q

*What is the sp content of 3.2% Na citrate?

A

0.109 M Na citrate

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13
Q

What is the B:AC ratio of 3.2% Na citrate?

A

9:1

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14
Q

What are the uses of citrated bld?

A
  1. Aggregation studies
  2. Coagulation studies
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15
Q

What is the sx used for aggregation studies and how is this sx obtained?

A

PRP

Centri @ 60 - 100 g for 30 mins

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16
Q

What is the sx used for coagulation studies and how is this sx obtained?

A

PRP

Centri @ 2,000 - 2,300 g for 10 - 15 mins

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17
Q

What are the anticoagulants used in PLT ct?

A
  1. EDTA
  2. 3.2% Na citrate
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18
Q

When to use 3.2% Na citrate as anticoagulant in PLT ct?

A

Can be used when PLT satellitism occurs

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19
Q

What must be done to PLT ct if 3.2% Na citrate is used as anticoagulant?

A

PLT ct is multiplied by 1.1

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20
Q

What is the counting chamber used in PLT ct?

A

Neubauer counting chamber

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21
Q

What is the pipet used in PLT ct?

A

RBC Thoma pipet

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22
Q

What is the dilution used in PLT ct?

A

1:100 / 1:200

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23
Q

What must be the characteristic of diluting fluid used in PLT ct?

A

Must preserve PLT integrity while inhibiting their aggregation

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24
Q

What are the methods that can be used in PLT ct?

A
  1. Tocantin’s method
  2. Brecker-Cronkite method
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25
Q

What is the diluting fluid used in Tocantin’s method?

A

Rees-Ecker

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26
Q

What is the stain used in Tocantin’s method?

A

Brilliant cresyl blue (BCB)

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27
Q

What is the formula (per uL) used for Tocantin’s method?

A

Total PLTs cted X 200 (dilution) X 10 (depth correction) / 1 (area correction)

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28
Q

What microscopy is used in Brecker-Cronkite method?

A

Phase-contrast microscopy method

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29
Q

What is the diluting fluid used in Brecker-Cronkite method and what is its fxn?

A

1% ammonium oxalate

Hemolyze the RBCs

30
Q

What is the formula (per uL) used for Brecker-Cronkite method?

A

Total PLTs X 200 (dilution) X 10 (depth correction) / 0.2 (area correction)

31
Q

What is the formula used for PLT ct?

A

PLT ct = ave no. of PLT cted X dilution factor X area correction factor X depth correction factor

32
Q

What is the normal value of PLTs in PLT ct?

A

150,000 - 450,000/uL

33
Q

How is estimation of PLT # done and what is the formula used?

A

Scan 10 OIFs for # of PLTs

Ave # of PLTs X 20,000

34
Q

How is PLT estimate interpretation done?

A

Examine under OIF

35
Q

What are the PLT estimate interpretation based on various PLT estimate values?

A

0 - 49,000: markedly decreased
50,000 - 99,000: moderately decreased
100,000 - 149,000: slightly decreased
150,000 - 200,000: low normal
200,000 - 399,000: normal
400,000 - 599,000: slightly increased
600,000 - 799,000: moderately increased
above 800,000: markedly increased

36
Q

What is clot retraction?

A

When coagulation is complete, the clot normally undergoes clot retraction (serum is expressed from the clot), and the clot becomes denser

37
Q

What is the characteristic of clot retraction?

38
Q

What are the uses of clot retraction?

A
  1. Screening test for PLT fxn
  2. Useful index of PLT activity
39
Q

True or False

Clot retraction is poor when PLT ct is > 100,000/uL

A

False, because clot retraction is poor when PLT ct is < 100,000/uL

40
Q

Abnormal clot retraction result indicates what dses?

A
  1. Glanzmann’s thrombasthenia
  2. Paraproteinemia (multiple myeloma)
    => PROs interfere w/ fibrin formation
41
Q

What are responsible for clot retraction?

A
  1. Actin
  2. Myosin
  3. Thrombosthenin
42
Q

What is clot retraction test?

A
  1. A normal clot contracts and in so doing it express serum
  2. The degree of clot retraction can be measured on the amt of serum expressed
43
Q

What are the 2 types of tests in clot retraction test?

A
  1. Qualitative test
    a. Hirschboeck method
  2. Quantitative test
    a. Stefanini method
    b. MacFarlane method
44
Q

What is the use of qualitative test (in clot retraction test)?

A

For presence / absence of retraction

45
Q

What is the use of quantitative test (in clot retraction test)?

A

Estimate the amt / degree of retraction

46
Q

Hirschboeck method is also known as what?

A

Castor oil method

47
Q

What is the positive result in Hirschboeck method?

A

Dimpling / extrusion of droplet-like serum on top portion of the drop of bld

48
Q

What is the normal value of Hirschboeck method?

A

15 - 45 mins

49
Q

What are the interpretations if the results of clot retraction test have:
1. Dimpling in < 15 mins
2. Dimpling in > 45 mins

A
  1. Thrombotic tendency
  2. Hemorrhagic tendency
50
Q

What are the normal characteristics of extruded serum (in clot retraction test) and what are their indications?

A
  1. Milky
    a. Leukemia
    b. Diabetes
    c. After means
  2. Dark yellow
    a. Jaundice
  3. Cloudy
    a. Multiple myeloma
51
Q

What are the characteristics of Stefanini method?

A
  1. Clot retraction starts within 1 hr
  2. It is complete within 18 - 24 hrs
52
Q

What are the manners of reporting of Stefanini method?

A
  1. Normal or complete retractility
  2. Partial retractility
  3. Poor retractility
  4. Very poor retractility
53
Q

What is the normal value of McFarlane method?

54
Q

What is the formula of McFarlane method?

A

% Clot retraction = amount of serum left in tube / amount of whole blood used X 100%

55
Q

What are the tests for hemostasis?

A
  1. Bleeding time
  2. Whole bld clotting time
  3. Manual detection of fibrin clot
  4. Tourniquet test
  5. PLT aggregometry
  6. Poor man’s PLT aggregation
  7. Prothrombin time (PT)
  8. Activated partial thromboplastin time (APTT)
  9. Stypven time
  10. Thrombin time (TT)
  11. Reptilase time (RT)
  12. Plasma recalcification time
  13. Duckert’s test
  14. Substitution test
  15. Fibrinosticon
  16. Ethanol gelation test
  17. Protamine sulfate
  18. Euglobulin clot lysis time
  19. PLT neutralization procedure
  20. Fibrinogen assay
  21. Bethesda assay
  22. Diluted Russel Viper Venom TIme (DRVVT)
  23. D-dimer test
56
Q

What is bleeding time?

A

The time it takes for a std wound to stop bleeding

57
Q

What is the use of bleeding time?

A

Screening test for primary hemostasis

58
Q

What is the normal value of bleeding time?

A

2 - 4 mins

59
Q

What are the other types / methods of bleeding time?

A
  1. Duke
  2. Ivy
  3. Mielke
60
Q

What is the procedure in Duke (bleeding time)?

A
  1. Earlobe / fingertip was punctured using a sterile bld lancet
  2. The wound should be blotted every 30 secs
61
Q

What are the characteristics of Duke (bleeding time)?

A
  1. Not precise
  2. Accurate
62
Q

What is the procedure in Ivy (bleeding time)?

A

BP cuff (40 mmHg)

63
Q

*What is the procedure in Mielke (bleeding time)?

A

Standardization of wound

64
Q

What is the use of WB clotting time?

A

For primary hemostasis

65
Q

What is the principle of WB clotting time?

A

When venous bld is put into a foreign substance, it will form a solid clot

66
Q

What must be considered in WB clotting time?

A

Clotted sx = low result

67
Q

What are the other methods of WB clotting time?

A
  1. Lee and White method
  2. Capillary method / Dale and Laidlaw
68
Q

What is used in Lee and White method?

A

75 x 100 mm test tube

69
Q

What is the normal value of Lee and White method (WB clotting time)?

A

5 - 15 mins

70
Q

What is the normal value of capillary method / Dale and Laidlaw (WB clotting time)?

A

2 - 4 mins

Hematology (S) (5 decks)

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