PREFINAL LABORATORY L2: CT/BT

Question 1

what does bleeding time evaluate

Answer 1

function of platelets, von Willebrand factor and small blood vessels

Question 2

is bleeding time a screening or diagnostic test

Answer 2

screening test

Question 3

bleeding time is directly affected by what factors

Answer 3

platelet count and platelet’s ability to form a plug

Question 4

it is required for platelet adhesion to a vessel wound with exposed subendothelial collagen

Answer 4

von Willebrand factor

Question 5

factors that may affect the result of bleeding time

Answer 5

1) deficiency in von Willebrand factor
2) thickness of bv
3) ability to constrict and retract of bv

Question 6

T or F:
Coagulation process does not affect the bleeding time

Answer 6

T
(unless there is a presence of severe deficiency)

Question 7

how can aspirin affect bleeding time

Answer 7

prolong bleeding time by helping not to have thrombus formation

Question 8

bleeding time should not be performed after taking aspirin for how many days

Answer 8

7 days

Question 9

bleeding time should not be performed after taking NSAIDs for how long

Answer 9

24 hours

Question 10

two methods of bleeding time

Answer 10

Ivy method
Duke method

Question 11

identify:
an incision on the volar surface of the arm is made

Answer 11

Ivy method

Question 12

in Ivy method, the sphygmomanometer is used and inflated up to how many mmHg

Answer 12

40 mmHg

Question 13

identify:
performed by making a puncture in the earlobe and the time required for the bleeding to stop is measured

Answer 13

Duke method

Question 14

In Duke method, what is the depth of the puncture using a sterile lancet

Answer 14

2-3 mm

Question 15

in Duke method, when is the stopwatch started

Answer 15

when the first drop of blood appears

Question 16

how many seconds is the interval in Duke method

Answer 16

15 or 30 seconds

Question 17

reference value of Ivy method

Answer 17

2-9 minutes

Question 18

reference value of Duke method

Answer 18

1-3 minutes

Question 19

in Ivy method, puncture must be made in an area that is free of

Answer 19

large superficial blood vessels

Question 20

depth of puncture in Ivy method

Answer 20

3 mm

Question 21

when is the sphygmomanometer removed in Ivy method

Answer 21

after the bleeding ceases

Question 22

assesses platelet function by measuring how quickly a blood clot shrinks and draws the edges of a broken blood vessel together

Answer 22

clot retraction test

Question 23

principle of clot retraction test

Answer 23

fresh whole clotted blood is placed in a 37C water bath and inspected at 1, 2, 4 and 24 hours for the presence of retracted clot

Question 24

when is maximum clot retraction observed

Answer 24

24 hours, time the dot occupies about half the original blood volume

Question 25

normally, when does clot retraction commences

Answer 25

within 30 seconds after the blood has clotted

Question 26

there should be appreciable clot retraction at the end of how many hours

Answer 26

1 hour

Question 27

most retraction occurs within how many hours

Answer 27

first 4 hours

Question 28

clot retraction should be complete within how many hours

Answer 28

24 hours

Question 29

abnormal clot retraction time is observed in what conditions

Answer 29

1) Glanzmann's thrombasthenia 2) thrombocytopenia 3) paraproteinemia (e.g. multiple myeloma)

Question 30

in what disease where there is a small clot formed with an increased amounts of red blood cells expressed from the clot

Answer 30

dysfibrinogenemia or hypofibrinogenemia

Question 31

term used to describe a small clot formed with an increased amounts of RBC expressed from the clot

Answer 31

RBC fall out

Question 32

what happens in paraproteinemia

Answer 32

there is interference of fibrin formation by abnormal proteins

Question 33

what happens in DIC

Answer 33

the formed clot will appear small and ragged with increased RBC fall out

Question 34

what is the degree of clot retraction in specimen with erythrocytosis

Answer 34

limited due to large volume of blood cells within the clot

Question 35

what is the degree of clot retraction in specimen with anemic conditions

Answer 35

increased

Question 36

manner of reporting of clot retraction

Answer 36

1) no retraction 2) partial retraction 3) complete retraction 4) very poor 5) poor 6) partial normal retraction

Question 37

methods of clotting time

Answer 37

Slide method Lee & White method

Question 38

principle of clotting time

Answer 38

the coagulation time of whole blood is the length of time required for a measured volume of blood to clot under specific conditions

Question 39

the lack of sensitivity and precision of the LW led researchers to look for better methods of monitoring what

Answer 39

heparin therapy

Question 40

this was recognized to be sensitive to heparin

Answer 40

Partial Thromboplastin Time (PTT)

Question 41

what year was PTT recognized

Answer 41

1964

Question 42

who developed the activated clotting time test (ACT)

Answer 42

Dr. Paul Hattersley

Question 43

how many mL of whole blood is used in ACT

Answer 43

2mL

Question 44

tube used in ACT

Answer 44

gray stoppered BD vacutainer with diatomaceous earth (diatomite)

Question 45

function of diatomaceous earth

Answer 45

functions as the activator of the contact factors

Question 46

contact factors

Answer 46

1) factor XII (Hageman factor) 2) high-molecular weight kininogen 3) prekallikrein

Question 47

ACT required blood to be constantly warmed at what temp

Answer 47

37C

Question 48

when is the tube tilted in ACT

Answer 48

after the 1st minute

Question 49

how many second intervals in ACT

Answer 49

5-10 until the clot forms

Question 50

coagulation is normally complete for how long

Answer 50

less than 101 seconds

Question 51

this is commonly known as clotting time

Answer 51

capillary blood method (slide method)

Question 52

reference value of clotting time

Answer 52

2-4 minutes

Question 53

what should be observed in clotting time before stopping the timer

Answer 53

fibrin thead

Question 54

how many tubes are used in Lee and White

Answer 54

3 13x100 mm test tube

Question 55

needle gauge used in LW method

Answer 55

20

Question 56

amount of blood drawn in LW method

Answer 56

4 mL

Question 57

how many mL of blood in each tube in LW

Answer 57

1 mL each, last 1mL is discarded

Question 58

when is the timer started in LW method

Answer 58

after blood is placed in tube #3

Question 59

when is the #1 tube tilted

Answer 59

5 minutes

Question 60

angle of the tube should be tilted

Answer 60

45 degrees

Question 61

the tube is titled every how many seconds

Answer 61

30 seconds until the blood is completely clotted

Question 62

how many seconds before proceeding with test tube #2

Answer 62

30 seconds after tube #1 is clotted

Question 63

what tube is the reported result

Answer 63

#3

Question 64

why is tube #3 the reported result

Answer 64

since agitation and handling speed up coagulation

Question 65

reference value of LW method

Answer 65

5-15 minutes