Question 1

Give the results (prolonged or normal) for the bleeding time, prothrombin time, activated partial thromboplastin time, and thrombin time for a patient on prolonged anticoagulant therapy.

Accepted Answer

A)BT: Bleeding time assesses primary hemostasis, so prolonged anticoagulant therapy should not affect the BT.
B)PT: If the patient is taking coumadin, the PT time will be prolonged.
C)APTT: If the patient is on heparin, the APTT will be prolonged.
D)TT: Heparin will almost certainly cause a prolonged TT.

Question 2

Laboratory screening test results strongly suggest heparin contamination.Which of the following tests would help assess this finding?
A)DRVVT
B)Reptilase time
C)APTT 
D)AT III activity

Accepted Answer

B

Question 3

A patient is admitted with prolonged epistaxis and prolonged bleeding from a recent tooth extraction.Initial screening workup reports prolonged APTT and BT, and abnormal aggregation on the PFA.Which of the following tests would help define the disorder?

Accepted Answer

A)  von Willebrand's factor activity
B)  von Willebrand's factor antigen
C)  Factor VIII assay
D)  All of the above D

Question 4

A patient is screened positive for APCR.What does this mean for the patient?

Accepted Answer

A)  The patient is at risk for hemorrhage.
B)  The patient has a factor VLₑᵢdₑn mutation.
C)  The patient is at risk for thrombosis.
D)  The patient is on heparin.

Question 5

A patient with a fibrinolytic deficiency would:

Accepted Answer

A)  Be prone to increased lysis.
B)  Have increased levels of plasminogen.
C)  Have abnormal screening tests (PT and APTT) .
D)  Be prone to increased clotting.

Question 6

Proper pecimen collection for coagulation testing must be performed to eliminate contamination of substances that will interfere with the test results.Which of the following are considered contaminates for coagulation testing?

Accepted Answer

A)  Sodium citrate and heparin anticoagulant
B)  Tissue factor and anticoagulant carryover
C)  Air and tissue factor
D)  High hematocrit and anticoagulant carryover

Question 7

A patient's laboratory coagulation testing results in an immediate correction of the PT and aPTT after mixing studies, and no correction after performing the PT and aPTT after a 2-hour incubation at 37°C.What is the possible deficiency or inhibitor?

Accepted Answer

A)  Factor deficiency
B)  Lupuslike anticoagulant
C)  F-VIII inhibitor
D)  F-V loss

Question 8

The Thrombin Time is prolonged with a patient having:

Accepted Answer

A)  Increased levels of fibrin degration products.
B)  Increased levels of fibrinogen.
C)  Factor deficiencies.
D)  Presence of lupus anticoagulants.

Question 9

The anticoagulant of 3.2% sodium citrate is preferred over 3.8% because:

Accepted Answer

A)  It does not require an adjusted redraw on patients with high hematocrits.
B)  3.8% sodium citrate tubes are no longer manufactured.
C)  The 3.2% sodium citrate has more success with minimizing in vitro platelet activation.
D)  It is more likely to prevent clotting with difficult draws.

Question 10

The Prothrombin Time measures the clotting factors in the:

Accepted Answer

A)  Intrinsic pathway.
B)  Formation of fibrin.
C)  Extrinsic pathway.
D)  Fibrinolytic pathway.

Question 11

Using the PRP, platelet-rich plasma, in the aggregation studies of a patient's blood, the results were typical of the RIPA, ristocetin-induced platelet agglutination defect.The RIPA defect was corrected by adding normal plasma to the patient's PRP.In what disease is this seen?

Accepted Answer

A)  Sticky platelet syndrome
B)  Bernard-Soulier syndrome
C)  Afibrinogenemia
D)  von Willebrand's disease

Question 12

Explain the clinical significance of a prolonged time with each of the following:
A)Bleeding time.
B)Prothrombin time.
C)Activated partial thromboplastin time.
D)Thrombin time.

Accepted Answer

The answer of Explain the clinical significance of a prolonged...

Question 13

An outpatient has an INR of 6.5.Previous testing at the same facility had results in the normal range of 2-3 for this patient on long-term anticoagulant therapy.The appropriate next step for the laboratorian would be:

Accepted Answer

A)  Retest the patient sample.
B)  Contact the physician ordering the test.
C)  Contact the patient to return for repeat testing.
D)  All of the above.

Question 14

Interpret the results below.
a.PT = 32 sec
b.APTT = 92 sec
c.TT = 20 sec.
What is the most likely reason for these aberrant results?

Accepted Answer

A)  The patient is in DIC.
B)  There is heparin contamination of the sample.
C)  The patient is taking coumadin.
D)  The patient has liver disease.

Question 15

Explain the effects of the following on coagulation testing:
A)Clotted sample
B)Ratio of blood to anticoagulant < 9:1
C)Patient hematocrit >55%
D)Greater than 1-hour difference between specimen collection and analysis

Accepted Answer

The answer of Explain the effects of the following on...

Question 16

Proper collection and processing of coagulation specimens is necessary for optimum results.What should be avoided when processing the sodium citrated specimens for testing?

Accepted Answer

A)  Hemolysis and overfilling of the tube
B)  Platelet-rich plasma
C)  Clotting of the specimen and underfilling of the tube
D)  Overfilling of the tube and lipemia

Question 17

Based on the following laboratory data: PT: normal
APTT: prolonged
Factor VIII: C assay: <1%
Which of the following is the most appropriate reflex test?

Accepted Answer

A)  DRVVT
B)  Bethesda titer
C)  Factor IX assay
D)  Mixing studies

Question 18

A hemophilic patient (Hemophilia A) has a severe bleed and is being treated with Factor VIII concentrate.When testing his post-infusion, the factor VIII level does not increase.The problem could be:

Accepted Answer

A)  Lupus anticoagulant.
B)  Improper drawing of the specimen.
C)  Factor VIII Inhibitor.
D)  Factor IX inhibitor.

Question 19

In performing testing for thrombotic disorders, the ideal testing would be:

Accepted Answer

A)  Antigenic measurement of PC, PS, ATIII.
B)  Functional measurement of PC, PS, ATIII.
C)  Platelet Function Testing.
D)  Lupus anticoagulant.

Question 20

Which of the following tests is used to assess platelet function in vivo?

Accepted Answer

A)  Protime
B)  Activated partial thromboplastin time
C)  Bleeding time
D)  Platelet aggregation studies

Exam 39: Laboratory Testing in Coagulation