Hemostasis- Lab Determinations 2023 Questions and
Answers Verified 100%
What is the correct procedure when using a winged collection device (butterfly) to draw
a light-blue top tube intended for a coagulation test if this is the first tube that will be
collected in the draw?
Draw and discard a waste light-blue top tube before the tube that will be used for
coagulation studies.
A test used to evaluate the abnormalities in the intrinsic coagulation pathway and to
monitor heparin therapy is called:
Prothrombin time (PT)
The dissolution of a clot with 5M urea indicates which one of the following factor
deficiencies?
Factor XIII
What is the International Normalized Ratio (INR) calculation used for?
Standardize PT results between different reagent sensitivities
What is the anticoagulant most commonly used for routine coagulation testing?
Sodium citrate
You have just performed stat PT and aPTT tests on your coagulation instrument. Your
results are as follows:
PT = 12 seconds (normal range 10-13 seconds)
aPTT = 24 seconds (normal range 21-34 seconds)
What would be your next step?
Report the results.
Which potent inhibitor of platelet aggregation is released by endothelial cells?
Prostacyclin
Dysfibrinogenemia can be caused by many different structural mutations of the
fibrinogen genes, and can result in bleeding, thrombosis, or in some patients, no
symptoms. A lab test which differentiates dysfibrinogenemia from afibrinogenemia is:
Fibrinogen antigen assay
A prothrombin time (PT) specimen was collected at an outpatient clinic and will not be
picked up by the testing laboratory's courier until several hours later. How should the
specimen be stored until it is picked up by the courier?
The tube should remain unopened and be kept at room temperature (20°-25° C).
After the physician orders a follow up for abnormal coagulation screening tests, the
laboratorian completes a mixing study with the following results:
Initial aPTT result: 98 seconds
Initial 1:1 Mix with Normal Pooled Plasma: 28 seconds
Incubated 1:1 Mix with Normal Pooled Plasma: 30 seconds
Which of the choices below would most likely explain the results for this patient?
Factor VIII deficiency
The D-dimer is useful in detecting activity in which aspect of hemostasis?
Fibrinolysis
A D-dimer test is collected in which color test tube?
Light blue
, Which of the following laboratory tests of hemostatic function is a screening test used to
assess the functionality of both the intrinsic and common pathways?
Activated partial thromboplastin time (aPTT)
A newly admitted patient has the following coagulation results:PT: 12.9 seconds (N =
12-14 seconds)aPTT: 84 seconds (N = 25-35 seconds)Platelet Count: 200 x 109/L (N =
150-450 x 109/L)
A mixing study was performed due to the abnormal aPTT test results. The mixing study
demonstrated the following:aPTT was corrected by normal plasma, factor IX deficient
plasma, but not by factor VIII deficient plasma.
What factor assay should be performed next?
Factor VIII assay
Which of the following laboratory results would you find with disseminated intravascular
coagulation (DIC) but NOT with thrombotic thrombocytopenic purpura (TTP) or
hemolytic uremic syndrome (HUS)?
Prolonged PT and aPTT
All of the following disorders would affect the results of a Prothrombin time
(PT) EXCEPT?
Factor VIII deficiency
What may prevent the detection of lupus anticoagulant in a plasma sample if the blood
used for testing is not centrifuged for a sufficient time?
Increased platelets in the plasma sample
Von Willebrand Factor (vWF) multimer analyses of patient's plasma can be performed
by:
SDS agarose gel electrophoresis
All of the following tests are useful in the diagnosis of heparin induced
thrombocytopenia (HIT) EXCEPT:
Dilute partial thromboplastin time (DTT)
A patient with a history of frequent mild bleeding episodes has the following results:
Normal PTProlonged aPTT corrected by normal plasma during mixing studies
Which of the following could be a possible cause of the initial aPTT prolongation?
Factor IX deficiency
The clot-based assay that is most specific for measuring fibrinogen function is the:
Thrombin Time (TT)
Which of the following assays is commonly used to confirm the diagnosis of Activated
Protein C resistance?
Factor V Leiden Mutation Assay
All of the following are coagulation assays that employ low-reagent phospholipids and
thus are sensitive to Lupus Anticoagulant (LA) (Antiphospholipid Antibodies) EXCEPT:
Activated partial thromboplastin time (aPTT
Which of the following blood collection tubes is appropriate for coagulation testing?
bLUE
A patient has a history of repeated spontaneous abortion. Coagulation studies reveal an
elevated APTT, normal PT, normal platelet function, and normal thrombin time.
Schistocytes were seen on the peripheral blood smear.
Which test should be performed to determine if the patient has lupus anticoagulant?
Platelet neutralization test
Answers Verified 100%
What is the correct procedure when using a winged collection device (butterfly) to draw
a light-blue top tube intended for a coagulation test if this is the first tube that will be
collected in the draw?
Draw and discard a waste light-blue top tube before the tube that will be used for
coagulation studies.
A test used to evaluate the abnormalities in the intrinsic coagulation pathway and to
monitor heparin therapy is called:
Prothrombin time (PT)
The dissolution of a clot with 5M urea indicates which one of the following factor
deficiencies?
Factor XIII
What is the International Normalized Ratio (INR) calculation used for?
Standardize PT results between different reagent sensitivities
What is the anticoagulant most commonly used for routine coagulation testing?
Sodium citrate
You have just performed stat PT and aPTT tests on your coagulation instrument. Your
results are as follows:
PT = 12 seconds (normal range 10-13 seconds)
aPTT = 24 seconds (normal range 21-34 seconds)
What would be your next step?
Report the results.
Which potent inhibitor of platelet aggregation is released by endothelial cells?
Prostacyclin
Dysfibrinogenemia can be caused by many different structural mutations of the
fibrinogen genes, and can result in bleeding, thrombosis, or in some patients, no
symptoms. A lab test which differentiates dysfibrinogenemia from afibrinogenemia is:
Fibrinogen antigen assay
A prothrombin time (PT) specimen was collected at an outpatient clinic and will not be
picked up by the testing laboratory's courier until several hours later. How should the
specimen be stored until it is picked up by the courier?
The tube should remain unopened and be kept at room temperature (20°-25° C).
After the physician orders a follow up for abnormal coagulation screening tests, the
laboratorian completes a mixing study with the following results:
Initial aPTT result: 98 seconds
Initial 1:1 Mix with Normal Pooled Plasma: 28 seconds
Incubated 1:1 Mix with Normal Pooled Plasma: 30 seconds
Which of the choices below would most likely explain the results for this patient?
Factor VIII deficiency
The D-dimer is useful in detecting activity in which aspect of hemostasis?
Fibrinolysis
A D-dimer test is collected in which color test tube?
Light blue
, Which of the following laboratory tests of hemostatic function is a screening test used to
assess the functionality of both the intrinsic and common pathways?
Activated partial thromboplastin time (aPTT)
A newly admitted patient has the following coagulation results:PT: 12.9 seconds (N =
12-14 seconds)aPTT: 84 seconds (N = 25-35 seconds)Platelet Count: 200 x 109/L (N =
150-450 x 109/L)
A mixing study was performed due to the abnormal aPTT test results. The mixing study
demonstrated the following:aPTT was corrected by normal plasma, factor IX deficient
plasma, but not by factor VIII deficient plasma.
What factor assay should be performed next?
Factor VIII assay
Which of the following laboratory results would you find with disseminated intravascular
coagulation (DIC) but NOT with thrombotic thrombocytopenic purpura (TTP) or
hemolytic uremic syndrome (HUS)?
Prolonged PT and aPTT
All of the following disorders would affect the results of a Prothrombin time
(PT) EXCEPT?
Factor VIII deficiency
What may prevent the detection of lupus anticoagulant in a plasma sample if the blood
used for testing is not centrifuged for a sufficient time?
Increased platelets in the plasma sample
Von Willebrand Factor (vWF) multimer analyses of patient's plasma can be performed
by:
SDS agarose gel electrophoresis
All of the following tests are useful in the diagnosis of heparin induced
thrombocytopenia (HIT) EXCEPT:
Dilute partial thromboplastin time (DTT)
A patient with a history of frequent mild bleeding episodes has the following results:
Normal PTProlonged aPTT corrected by normal plasma during mixing studies
Which of the following could be a possible cause of the initial aPTT prolongation?
Factor IX deficiency
The clot-based assay that is most specific for measuring fibrinogen function is the:
Thrombin Time (TT)
Which of the following assays is commonly used to confirm the diagnosis of Activated
Protein C resistance?
Factor V Leiden Mutation Assay
All of the following are coagulation assays that employ low-reagent phospholipids and
thus are sensitive to Lupus Anticoagulant (LA) (Antiphospholipid Antibodies) EXCEPT:
Activated partial thromboplastin time (aPTT
Which of the following blood collection tubes is appropriate for coagulation testing?
bLUE
A patient has a history of repeated spontaneous abortion. Coagulation studies reveal an
elevated APTT, normal PT, normal platelet function, and normal thrombin time.
Schistocytes were seen on the peripheral blood smear.
Which test should be performed to determine if the patient has lupus anticoagulant?
Platelet neutralization test
