Hemostasis

c. Tissue plasminogen activator (t-PA)

A substance secreted by the vascular endothelial cells that can help to initiate fibrinolysis is: a. Tissue factor (TF) b. Tissue factor pathway inhibitors (TFPI) c. Tissue plasminogen activator (t-PA) d. Von Willebrand factor (vWF)

d. Common pathway

In the in vitro coagulation scheme, factor V is primarily involved in the: a. Extrinsic pathway ONLY b. Intrinsic pathway ONLY c. Fibrinolytic pathway d. Common pathway

c. Thrombosis

Obstruction of a blood vessel caused by a stationary blood clot is called: a. Phlebitis b. Embolism c. Thrombosis d. Aneurysm

c. Fragments of megakaryocyte cytoplasm and do not contain nuclei

Platelets are: a. The smallest nucleated cells seen in normal peripheral blood. b. The largest nucleated cells seen in normal peripheral blood. c. Fragments of megakaryocyte cytoplasm and do not contain nuclei d. Fragments of neutrophils

c. Spleen

Removal of which of these organs may be a last resort treatment for a patient whose platelet count is less than 30 x 109/L as a result of chronic idiopathic thrombocytopenic purpura (ITP)? a. Gall bladder b. Pancreas c. Spleen d. A kidney

a. Factor V Leiden Mutation Assay

Which of the following assays is commonly used to confirm the diagnosis of Activated Protein C resistance? a. Factor V Leiden Mutation Assay b. Antithrombin Activity Assay c. Antithrombin Antigen Assay d. Anticardiolipin Antibody Immunoassay

d. Plasminogen

A 3-year-old child was brought into the hospital with complaints of recurring conjunctivitis along with "woody" growths on the mucous membranes. Which of the following deficiencies would occur given these symptoms? a. Factor VII b. Von Willebrand Factor c. Antithrombin d. Plasminogen

b. Von Willebrand factor

A defect in which of the following factors causes impaired platelet adhesion and aggregation? a. Stuart-Prower factor b. Von Willebrand factor c. Hageman factor d. Fletcher factor

b. Lack of or defect of platelet receptor IIb/IIIa

A defective clot retraction might be caused by which one of these? a. Lack of or defect of platelet receptor glycoprotein Ib/IX/V b. Lack of or defect of platelet receptor IIb/IIIa c. Insufficient storage of ADP in platelet granules d. Absence or defect of von Willebrand's Factor

a. Excessive and unregulated fibrinolysis

A deficiency in Plasminogen Activator Inhibitor-1 (PAI-1) can lead to a serious bleeding disorder due to which of the following? a. Excessive and unregulated fibrinolysis b. Excessive thrombosis c. Unregulated thrombosis d. Unregulated platelet aggregation

d. Vitamin K

A deficiency in which of these vitamins leads to increased clotting time and may result in hemorrhagic disease? a. Riboflavin b. Pyridoxine c. Vitamin C d. Vitamin K

d. Prolonged aPTT and normal reptilase time test

A specimen drawn from an indwelling catheter that was contaminated by heparin would be indicated by: a. Normal PT and aPTT results b. Prolonged PT and normal aPTT results c. Prolonged aPTT and prolonged reptilase time test d. Prolonged aPTT and normal reptilase time test

d. Platelet neutralization test

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? a. Factor VIII assay b. Mixing studies with factor-deficient plasmas c. Antinuclear antibody test d. Platelet neutralization test

a. Liver disease

A patient initially has a prolonged PT. After reviewing the patient's case and laboratory findings, the physician administers intravenous vitamin K. The repeat PT results are normal after 24 hours of vitamin K therapy. What clinical condition is MOST likely to produce these results? a. Liver disease b. Factor XI deficiency c. Fibrinogen deficency d. vWF deficency

b. Factor IX deficiency

A patient with a history of frequent mild bleeding episodes has the following results: Normal PT Prolonged aPTT corrected by normal plasma during mixing studies Which of the following could be a possible cause of the initial aPTT prolongation? a. Factor VII deficiency b. Factor IX deficiency c. Factor X deficiency d. A circulating inhibitor is present

a. Platelet function assay (PFA)

A point-of-care test used to evaluate bleeding problems and monitor antiplatelet medication is called? a. Platelet function assay (PFA) b. Prothrombin time (PT) c. Activated partial thromboplastin time (aPTT or PTT) d. Erythrocyte sedimentation rate (ESR)

c. The tube should remain unopened and be kept at room temperature (20°-25° C).

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? a. The specimen should be centrifuged right away and stored in the refrigerator at 4° C until is picked up the the courier. b. The specimen should be frozen immediately and kept there until is tested. c. The tube should remain unopened and be kept at room temperature (20°-25° C). d. The specimen should be protected from light.

B. Prothrombin time (PT)

A test used to evaluate abnormalities in the extrinsic coagulation pathway and to monitor coumarin therapy A. Platelet function assay (PFA) B. Prothrombin time (PT) C. Activated partial thrombloplastin time (aPTT or PTT) D. Erythrocyte sedimentation rate (ESR)

A. Platelet function assay (PFA)

A test used to evaluate bleeding problems and monitor antiplatelet medication A. Platelet function assay (PFA) B. Prothrombin time (PT) C. Activated partial thrombloplastin time (aPTT or PTT) D. Erythrocyte sedimentation rate (ESR)

C. Activated partial thrombloplastin time (aPTT or PTT)

A test used to evaluate the abnormalities in the intrinsic coagulation pathway and to monitor heparin therapy is called: A. Platelet function assay (PFA) B. Prothrombin time (PT) C. Activated partial thrombloplastin time (aPTT or PTT) D. Erythrocyte sedimentation rate (ESR)

c. Activated partial thrombloplastin time (aPTT or PTT)

A test used to evaluate the abnormalities in the intrinsic coagulation pathway and to monitor heparin therapy is called: a. Platelet function assay (PFA) b. Prothrombin time (PT) c. Activated partial thrombloplastin time (aPTT or PTT) d. Erythrocyte sedimentation rate (ESR)

c. Lithium or sodium heparin

A variety of additives are used in blood collection tubes. Which of the following additives prevents clotting by inhibiting thrombin and thromboplastin? a. EDTA b. Gel c. Lithium or sodium heparin d. Sodium fluoride

a. Low platelet count

Abnormal thrombin times (TT) can be caused by all of the following EXCEPT: a. Low platelet count b. High heparin levels c. Low fibrinogen levels d. High fibrin-degradation products

a. Anti-factor VIII inhibitor

Acquired hemophilia A (not classic hemophilia A) may be the result of which of the following conditions? a. Anti-factor VIII inhibitor b. Factor VIII deficiency c. Warfarin therapy d. Thrombosis complications

a. PT, aPTT. Lupus Anticoagulamt (LA) screening, Activated Protein C resistance (APC) , d-dimer screening

After several incidences of deep vein thrombosis (DVT), a patient is to be assessed for hypercoagulability. The following would be an appropriate panel for hypercoagulability screening: a. PT, aPTT. Lupus Anticoagulamt (LA) screening, Activated Protein C resistance (APC) , d-dimer screening b. LA screening, APC resistance c. D-dimer screening and Fibrin Degradation Products (FDP) test d. PT. aPTT, Thrombin Time (TT), Bleeding Time, and mixing studies

c. Factor VIII deficiency

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? a. Immediate-acting coagulation inhibitor b. Time/temperature-dependent coagulation inhibitor c. Factor VIII deficiency d. Factor VII deficiency

c. Activated partial thromboplastin time (aPTT)

All of the following are coagulation assays that employ low-reagent phospholipids and thus are sensitive to Lupus Anticoagulant (LA) (Antiphospholipid Antibodies) EXCEPT: a. Kaolin clotting time (KCT) b. Dilute Russell viper venom time (DRVVT) c. Activated partial thromboplastin time (aPTT) d. Dilute partial thromboplastin time (DTT)

C. Aspirin

All of the following are likely the causes of an abnormal thrombin time (TT) EXCEPT: A. Fibrin split products B. Heparin C. Aspirin D. Dysfibrinogenemia

c. Aspirin

All of the following are likely the causes of an abnormal thrombin time (TT) EXCEPT: a. Fibrin split products b. Heparin c. Aspirin d. Dysfibrinogenemia

a. Factor VIII deficiency

All of the following disorders would affect the results of a Prothrombin time (PT) EXCEPT? a. Factor VIII deficiency b. Coumadin therapy c. Vitamin K deficiency d. Alcoholic cirrhosis

d. Factor X

All of the following factors are involved in the initial contact phase of the intrinsic pathway, EXCEPT: a. Factor XII b. Fitzgerald Factor (high-molecular weight kininogen) c. Fletcher Factor (prekallikrein) d. Factor X

d. Plasminogen

All of the following substances can be used to induce platelet aggregation when performing platelet aggregation studies EXCEPT: a. Thrombin b. Adenosine diphosphate (ADP) c. Epinephrine d. Plasminogen

d. Dilute partial thromboplastin time (DTT)

All of the following tests are useful in the diagnosis of heparin induced thrombocytopenia (HIT) EXCEPT: a. Platelet aggregometry b. Enzyme-linked immunosorbant assay (ELISA) c. Carbon 14 serotonin washed platelet release assay d. Dilute partial thromboplastin time (DTT)

d. Fibrinogen

All of the following tests will be abnormal in a patient with Stuart-Prower Factor deficiency EXCEPT? a. Prothrombin Time (PT) b. Activated Partial Thromboplastin Time (APTT) c. Russel Viper Venom Test (dRVVT) d. Fibrinogen

a. Von Willebrand's disease

An 18-year-old patient bled profusely following a tooth extraction. She had a history of sporadically increased menstrual bleeding and nose bleeds. The laboratory tests showed: Platelet count of 350 x 109/L PT of 12 seconds PTT of 125 seconds Factor VIII activity of 20% Factor IX activity levels 102% Platelet aggregation studies - normal ADP, collagen and decreased with Ristocetin. What is the most likely cause of this patients bleeding episodes? a. Von Willebrand's disease b. Hemophilia A c. Hemophilia B d. Vascular Disease

d. Thrombocytosis

Disseminated intravascular coagulation (DIC) is associated with all of the following clinical conditions EXCEPT: a. Septicemia b. Obstetric emergencies c. Intravascular hemolysis d. Thrombocytosis

d. PT, aPTT and Ecarin clotting time

Anticoagulant drugs which are direct thrombin inhibitors (such as argatroban and bivalirudin) can prolong which of the following clot based assay/s? a. Ecarin clotting time only (ECT) b. Activated thromboplastin time (aPTT) only c. PT and aPTT d. PT, aPTT and Ecarin clotting time

d. 95%

Approximately what percentage of pulmonary emboli originate from deep veins of the legs? a. 65% b. 75% c. 85% d. 95%

a. Thromboxane A2

Aspirin ingestion prevents the synthesis of this signaling molecule in the platelet? a. Thromboxane A2 b. Calcium c. Collagen d. ADP

a. Increased in number and functionally abnormal

In essential thrombocythemia, the platelets are usually: a. Increased in number and functionally abnormal b. Normal in number and functionally abnormal c. Decreased in number and functionally normal d. Decreased in number and functionally abnormal

b. Factor VIII

Hemophilia A is associated with a deficiency of which of the following? a. Factor IX b. Factor VIII c. Factor X d. Factor V

d. Factor IX

Hemophilia B or Christmas disease is the result of a hereditary deficiency in which coagulation factor? a. Factor X b. Factor VIII c. Factor XI d. Factor IX

b. Release of urokinases

Patients who undergo urologic procedures, as well as those with genitourinary tract diseases such as prostate cancer can sometimes be prone to diffuse hemorrhage. A possible cause of this could be which of the following? a. Dysfunction of platelets b. Release of urokinases c. Initiation of tissue factor released from endothelial cells d. Release of PGL (a prostacyclin ) from endothelial cells

a. Fibrin

Plasmin is known to degrade Factors Va, VIIIa, and GPIb. What other substance is it known to digest? a. Fibrin b. Thrombin c. Plasminogen d. Hageman Factor

c. Ristocetin enhances binding of vWF to platelet GPIba.

Ristocetin is used in certain von Willebrand Factor (vWF) functional assays. The reason it is used is because: a. Ristocetin can prevent bacterial contamination of the specimen. b. Ristocetin can break down the vWF multimers into monomers, and then be assayed. c. Ristocetin enhances binding of vWF to platelet GPIba. d. Ristocetin prevents interference by other coagulation factors.

b. Rapid weight loss

Secondary hypercoagulable states can be caused by all of the following conditions EXCEPT: a. Obesity b. Rapid weight loss c. Pregnancy d. Postoperative states

d. Providing smooth endothelial surface

The vascular system contributes to hemostasis in all of the following ways EXCEPT: a. Production of tissue factor b. Diversion of blood flow around the damaged vessel c. Contraction of vessels d. Providing smooth endothelial surface

c. Fibrinolysis

The D-dimer is useful in detecting activity in which aspect of hemostasis? a. Primary hemostasis b. Secondary hemostasis c. Fibrinolysis d. Quaternary hemostasis

a. INR=(PT patient / PT normal) raised to the ISI.

The INR (international normalized ratio) is calculated using the following formula: a. INR=(PT patient / PT normal) raised to the ISI. b. INR=(PT patient / PT normal). c. INR=(PT patient / PT control) raised to the ISI. d. INR=(PT control / PT normal) raised to the ISI.

c. Hageman factor (XII)

The absence of which clotting factor causes NO bleeding tendency? a. Antihemophiliac factor (VIII) b. Plasma thromboplastin component (IX) c. Hageman factor (XII) d. Plasma thromboplastin antecedent (XI)

b. Factor XIII

The fibrin clot begins to form when fibrinogen is cleaved resulting in a fibrin monomer, fibrinopeptide A, and fibrinopeptide B fragments. The fibrin monomers spontaneously polymerize due to hydrogen bonding, and then are covalently linked into fibrin polymers by which factor? a. Plasmin b. Factor XIII c. Factor V d. Thrombin

a. Streptokinase

The fibrinolytic system may be activated by which one of the following? a. Streptokinase b. Streptolysin c. Fibrin d. EDTA

a. Intrinsic

Which coagulation pathway is initiated when collagen is exposed, and involves the substances high-molecular-weight kininogen (HK), prekallikrein (PK), and factor XII? a. Intrinsic b. Extrinsic c. Common d. Fibrinolysis

c. A parital thromboplastin time (PTT) is performed using C-depleted normal plasma, a venom activator of protein C (such as Protac), and a heparin neutralizer. The clotting time would not be prolonged in someone with a protein C deficiency

The following describes a clot-based test to assess Protein C function, as well as the results of someone's test who has a protein C deficiency. a. A partial thromboplastin time (PTT) is performed using C-depleted normal plasma, a venom activator of protein C (such as Protac), and a heparin neutralizer. The clotting time would be prolonged (above reference range) in someone with a protein C deficiency. b. A PTT is performed using low phospholipid reagents along with C-enriched plasma, a venom activator of protein C (such as Protac), and a heparin neutralizer. The clotting time would be prolonged (above reference range) in someone with a protein C deficiency. c. A parital thromboplastin time (PTT) is performed using C-depleted normal plasma, a venom activator of protein C (such as Protac), and a heparin neutralizer. The clotting time would not be prolonged in someone with a protein C deficiency. d. A PTT is performed using low phospholipid reagents along with C-enriched plasma, a venom activator of protein C (such as Protac), and a heparin neutralizer. The clotting time would not be prolonged in someone with a protein C deficiency.

D. Factor XIII

The following factors are measured by either the PT or aPTT, EXCEPT: A. Factor VIII B. Factor IX C. Factor V D. Factor XIII

b. Immediate-acting coagulation inhibitor

The laboratorian completed the mixing study ordered for John Doe. The results are as follows: Initial aPTT result: 167 seconds Initial 1:1 Mix with Normal Pooled Plasma: 158 seconds Incubated 1:1 Mix with Normal Pooled Plasma: 150 seconds Which of the choices below would most likely explain the results for this patient? a. Factor VIII deficiency b. Immediate-acting coagulation inhibitor c. Time/temperature-dependent coagulation inhibitor d. Factor VII deficiency

b. Extrinsic and common pathways

The prothrombin time test will detect deficiencies in which pathways? a. Extrinsic and intrinsic pathways b. Extrinsic and common pathways c. Intrinsic pathway and common pathways d. Intrinsic pathway only

b. Plasminogen

The thrombomodulin-thrombin complex is known to aid in the activation of which of the following? a. Factor VII b. Plasminogen c. Fibrin d. Factor XII

b. Thrombin time

This assay would be used to help rule-out heparin contamination in a coagulation sample: a. Protein C assay b. Thrombin time c. PT d. APTT

D. Factor deficiencies

Thromboelastography (TEG) is a methodology used to assess blood coagulation. The prothrombin time (PT) and activated partial thromboplastin time (APTT) are more commonly used. All of the following are things that TEG can assess that the PT and APTT cannot assess EXCEPT? A. Platelet function B. Clot strength C. Fibrinolysis D. Factor deficiencies

b. The entire coagulation status of the patient

Thromboelastography is a point of care test which measures which of the following? a. The elasticity of the patient's vasculature b. The entire coagulation status of the patient c. The ability of platelets to change shape d. Thromboembolisms in the patient's vessels

c. Prothrombotic state

Which condition is caused by the increased Plasminogen Activator Inhibitor 1 (PAI-1) and fibrinogen often present in metabolic syndrome? a. Hyperglycemia b. Proinflammatory state c. Prothrombotic state d. Atherogenic dyslipidemia

c. SDS agarose gel electrophoresis

Von Willebrand Factor (vWF) multimer analyses of patient's plasma can be performed by: a. Ristocetin induced platelet aggregation tests (RIPA) b. ELISA antigen assays c. SDS agarose gel electrophoresis d. Latex agglutination tests

d. Factor XI

Warfarin (coumarin-type anticoagulant) inhibits all the following coagulation factors except: a. Factor II b. Factor IX c. Factor VII d. Factor XI

a. Less than 40%

What MINIMUM level of a particular factor will cause the aPTT test to become prolonged? a. Less than 40% b. Less than 50% c. Less than 60% d. Less than 70%

c. Activated partial thromboplastin and calcium

What are the PRIMARY reagents used in the activated partial thromboplastin time (aPTT)? a. Thromboplastin and sodium chloride b. Activated partial thromboplastin and potassium c. Activated partial thromboplastin and calcium d. Actin and sodium chloride

a. Elevated PT, elevated aPTT, elevated thrombin time (TT) and elevated reptilase time

What are the expected lab results in the condition known as "Afibrinogenemia"? a. Elevated PT, elevated aPTT, elevated thrombin time (TT) and elevated reptilase time b. Elevated PT, elevated aPTT, elevated thrombin time (TT) and normal reptilase time c. Elevated PT, elevated aPTT, normal thrombin time (TT) and normal reptilase time d. Normal PT, elevated aPTT, normal thrombin time (TT) and elevated reptilase time

c. 9:1

What is the CORRECT blood-to-anticoagulant ratio in blue top (sodium citrate) tubes used for coagulation tests? a. 4:1 b. 5:1 c. 9:1 d. 10:1

b. Standardize PT results between different reagent sensitivities

What is the International Normalized Ratio (INR) calculation used for? a. Standardize PT and aPTT results b. Standardize PT results between different reagent sensitivities c. Standardize aPTT results between different reagent sensitivities d. Calibrate coagulation instruments for all coagulation testing

b. Draw and discard a waste light-blue top tube before the tube that will be used for coagulation studies.

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? a. Draw and discard a red-top tube that only contains an additive for clot activation before collecting the light-blue top tube that will be used for coagulation studies. b. Draw and discard a waste light-blue top tube before the tube that will be used for coagulation studies. c. Draw only the light-blue top tube that will be used for coagulation studies and then perform a second venipuncture for additional tubes. d. There is no correct procedure because a winged collection device cannot be used for collecting specimens for coagulation studies.

a. Cleaving ultra-large von Willebrand factor to keep them out of the circulation

What is the function of ADAMTS13 enzyme? a. Cleaving ultra-large von Willebrand factor to keep them out of the circulation b. Breaking down fibrinogen into fibrinogen split products (FSP) c. Transporting antibody coated platelets to the spleen d. Contributing to the maturation of megakaryocytes as a lineage specific cytokine

c. Formation of a fibrin clot

What is the ultimate goal of secondary hemostasis? a. Formation of a platelet plug b. Production of coagulation factors c. Formation of a fibrin clot d. Dissolution of the fibrin clot

c. Liver

What organ is associated with the production of the majority of clotting factors? a. Thymus b. Duodenum c. Liver d. Kidney

D. Platelet count

Which laboratory result is the most critical in recognizing heparin-induced thrombocytopenia (HIT)? A. Fibrinogen level B. Prothrombin time C. D-dimer D. Platelet count

c. Microthrombi disposition in small vessels

Which of the following causes schistocyte formation in disseminated intravascular coagulation (DIC)? a. Degranulation of promyelocytes b. Excessive fever in patients with DIC c. Microthrombi disposition in small vessels d. Excessive platelet size

c. Adenosine diphosphate (ADP)

Which of the following chemical substances induces platelet adhesion when there is a break in the inert epithelial lining of the vasculature? a. Epinephrine b. Factors IX and XIII c. Adenosine diphosphate (ADP) d. Thrombin

c. Both PT and aPTT

Which of the following coagulation test results would be prolonged in deficiency of Factor X? a. PT only b. aPTT only c. Both PT and aPTT d. Neither PT nor aPTT

d. Thrombin

Which of the following converts Fibrinogen into Fibrin Monomer? a. Heparin b. Calcium 2+ ions c. Tissue Factor d. Thrombin

c. Factor IX

Which of the following factors is Vitamin K-dependent? a. Factor I b. Factor VIII c. Factor IX d. Factor XI

b. Factor XII

Which of the following factors is known as Hageman factor? a. Factor X b. Factor XII c. Factor V d. Factor VII

b. Factor VII

Which of the following factors require Vitamin K for their synthesis in the liver? a. Factor XIII b. Factor VII c. Factor VIII d. Factor I

c. Activated Partial thromboplastin time (aPTT)

Which of the following is LEAST useful in differentiating hemophilia A from hemophilia B? a. Factor VIII and IX assays b. Clinical history c. Activated Partial thromboplastin time (aPTT) d. Mixing studies (correction studies)

c. Enzyme immunoassay

Which of the following is a quantitative test which is commonly available to determine Protein C and Protein S antigen levels? a. Modified partial thromboplastin time (PTT) b. Factor V Leiden assay c. Enzyme immunoassay d. Molecular test

a. Lupus anticoagulant (anti-phospholipid antibody)

Which of the following is considered one of the most common coagulation inhibitors? a. Lupus anticoagulant (anti-phospholipid antibody) b. Anti-factor II c. Anti-factor V d. Anti-factor X

d. Protein C

Which of the following is responsible for inhibiting the tissue plasminogen activator? a. Antithrombin b. Tissue Factor Pathway Inhibitor c. Thrombin d. Protein C

b. Fibrinogen

Which of the following is the common name for factor I? a. Prothrombin b. Fibrinogen c. Tissue factor d. Proaccelerin

d. Abnormal platelet aggregation response to ristocetin

Which of the following laboratory results is characteristic for a patient with Von Willebrand disease? a. Decreased bleeding time b. Normal FVIII levels c. Normal platelet function tests d. Abnormal platelet aggregation response to ristocetin

c. Prolonged PT, decreased fibrinogen, decreased platelet count, increased FDP

Which of the following laboratory results would be seen in a patient with acute Disseminated Intravascular Coagulation (DIC)? a. Prolonged PT, decreased fibrinogen, elevated platelet count, increased FDP b. Normal PT, decreased fibrinogen, decreased platelet count, decreased FDP c. Prolonged PT, decreased fibrinogen, decreased platelet count, increased FDP d. Normal PT, increased fibrinogen, decreased platelet count, decreased FDP

a. Prolonged PT and aPTT

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)? a. Prolonged PT and aPTT b. Thrombocytopenia c. Schistocytes on the peripheral blood smear d. Elevated LDH

c. Secondary hemostasis

Which of the following mechanisms involves a series of interrelated chemical processes that lead to the formation of durable fibrin strands? a. Fibrinolysis b. Primary hemostasis c. Secondary hemostasis d. Vasoconstriction

c. Factor VIII is deficient in hemophilia A and factor IX is deficient in hemophilia B.

Which of the following options best describes how hemophilia A differs from hemophilia B? a. The clinical presentation is drastically different. b. Hemophilia A is an inherited disorder and hemophilia B is an acquired disorder. c. Factor VIII is deficient in hemophilia A and factor IX is deficient in hemophilia B. d. Hemophilia A is a disorder of secondary hemostasis and hemophilia B is a disorder of primary hemostasis.

b. Fibrin strands added to the newly formed clot.

Which of the following processes does NOT occur during primary hemostasis? a. Physical decrease in the size of damaged vessel (vasoconstriction). b. Fibrin strands added to the newly formed clot. c. Blood flow rerouted around the damaged vessel. d. Platelets adhere to exposed collagen at the site of the breach.

d. Rapid and immediate vasoconstriction by contraction of smooth muscles.

Which of the following statements is true regarding primary hemostatic process resulting from vascular damage? a. Inhibition of platelet function by interaction with collagen. b. Platelet adhesion through Weibel-Palade bodies. c. Platelet aggregation through interaction of von Willebrand factor and glycoprotein IIb/IIIa. d. Rapid and immediate vasoconstriction by contraction of smooth muscles.

b. Negative test for D-dimers

Which of the following test results is INCONSISTENT with disseminated intravascular coagulation (DIC)? a. Decreased fibrinogen concentration b. Negative test for D-dimers c. Decreased platelet count d. Prolonged prothrombin time (PT) test

c. Factors II, VII, IX, X

Which of these coagulation factors are referred to as "vitamin-K dependent"? a. Factors I, V, VIII, XIII b. Factors II, V, IX, XII c. Factors II, VII, IX, X d. Factors XI, XII, Fletcher, Fitzgerald

a. Factor II

Which of these factors may be deficient if both the PT and aPTT are prolonged? a. Factor II b. Factor VII c. Factor VIII d. Factor XI

d. LA is an immunoglobulin.

Which one of the following is a true statement about Lupus Anticoagulant (LA)? a. LA is a specific inhibitor found mainly in patients with the autoimmune disease, Systemic Lupus Erythematosus (SLE), b. LA is common in hemophiliacs c. LA prolongs coagulation leading to bleeding problems in patients. d. LA is an immunoglobulin.

b. Reptilase Time

Which one of these test systems can be used to evaluate the adequacy of fibrinogen in heparinized patients? a. D-Dimer b. Reptilase Time c. Thrombin Time d. Prothrombin Time

B. Prostacyclin

Which potent inhibitor of platelet aggregation is released by endothelial cells? A. Epinephrine B. Prostacyclin C. Ristocetin D. Thromboxane A2

D. Immunologic fibrinogen level

Which test result will be normal in a patient with dysfibrinogenemia? A. Thrombin time B. APTT C. Fibrinogen assay D. Immunologic fibrinogen level

b. APTT

Which test result will be normal in a patient with dysfibrinogenemia? a. Thrombin time b. APTT c. Fibrinogen assay d. Immunologic fibrinogen level

d. Immunologic fibrinogen level

Which test result will be normal in a patient with dysfibrinogenemia? a. Thrombin time b. APTT c. Fibrinogen assay d. Immunologic fibrinogen level

d. Both 5 M urea clot solubility test and Factor XIII assay

Which tests will be abnormal in a patient with Fibrin Stabilizing factor deficiency? a. aPTT b. 5 M urea clot solubility test c. Factor XIII assay d. Both 5 M urea clot solubility test and Factor XIII assay

b. Anti-factor Xa assay (anti-FXa)

A laboratory test to determine heparin levels in a patient's plasma is: a. Activated partial thromboplastin time (aPTT) b. Anti-factor Xa assay (anti-FXa) c. Prothrombin time (PT) d. D-dimer assay

c. Factor VIII assay

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? a. None; a platelet disorder is indicated b. Factor V assay c. Factor VIII assay d. Factor IX assay

c. APTT

An abnormality of which of the following assays would be LEAST likely to be associated with thrombotic tendency? a. AT III b. Protein C c. APTT d. Protein S

d. Fibrinogen antigen assay

A lab test which differentiates dysfibrinogenemia from afibrinogenemia is: a. PT b. aPTT c. Thrombin Time (TT) d. Fibrinogen antigen assay

a. 4 hours

A laboratory professional is going to perform a mixing study to differentiate between a factor deficiency and a coagulation inhibitor as the cause of a prolonged prothrombin time (PT) or activated partial thromboplastin time (aPTT) test result. The mixing study should be performed within what time frame following collection of the specimen? a. 4 hours b. 8 hours c. 24 hours d. 48 hours

c. Factor Deficiency

An increased D-Dimer can be associated with all of the following EXCEPT: a. Pulmonary Embolism b. DIC c. Factor Deficiency D. Deep Vein Thrombosis

b. Direct thrombin inhibitors

In patients who have developed heparin-induced thrombocytopenia with thrombosis (HIT), which of the following should be used to prevent ischemic stroke? a. Unfractionated heparin b. Direct thrombin inhibitors c. Oral anticoagulant d. Vitamin K

C. Thrombin Time (TT)

The clot-based assay that is most specific for measuring fibrinogen function is the: A. Prothrombin Time (PT) B. Activated Partial Thromboplastin TIme (aPTT) C. Thrombin Time (TT) D. Immunoassay for fibrinogen

c. Thrombin Time (TT)

The clot-based assay that is most specific for measuring fibrinogen function is the: a. Prothrombin Time (PT) b. Activated Partial Thromboplastin TIme (aPTT) c. Thrombin Time (TT) d. Immunoassay for fibrinogen

b. Factor XIII

The dissolution of a clot with 5M urea indicates which one of the following factor deficiencies? a. Factor II b. Factor XIII c. von Willebrand disease d. Factor IX

b. Factor V Mutation Assay

The most specific test to detect both presence of Factor V Leiden, also known as activated protein C resistance (APC) and predict risk of thrombosis is: a. Activated Protein C Resistance (APC) clot-based assay b. Factor V Mutation Assay c. ELISA assay for Factor V Antithrombin antigen assay

c. Using specific antisera to detect d-dimers' neo-epitopes

The principle of most commercially available d-dimer assays is: a. Measuring the time it takes a patient's clot to lyse and form d-dimers b. Measuring plasminogen levels c. Using specific antisera to detect d-dimers' neo-epitopes d. Adding thrombin to patient plasma and measuring the time it takes to clot

c. >55%

The ratio of whole blood to anticoagulant is very important in the PT assay; at which hematocrit level should the standard anticoagulant volume be adjusted? a. < 50% b. >75% c. >55% d. < 35 %

a. Mix one part patient plasma and one part normal pooled plasma and repeat the aPTT

To determine if an elevated aPTT is caused by a factor deficiency or a factor inhibitor when the PT is normal, the FIRST step would be: a. Mix one part patient plasma and one part normal pooled plasma and repeat the aPTT b. Mix one part patient plasma and one part normal aged plasma and repeat the aPTT c. Perform a Factor IX assay to see if it is a Factor IX deficiency d. Perform a test for a lupus anticoagulant

b. Clot-based assays

Traditional coagulation assays are based almost solely on this technique: a. Chromogenic assays b. Clot-based assays c. RIA assays d. ELISA assays

b. Lyophilized Factor VIII concentrate

What is the first line treatment for moderate to severe hemophilia A? a. Platelets b. Lyophilized Factor VIII concentrate c. Factor IX complex d. Cryoprecipitated AHF

a. 1:1

What is the ratio of patient plasma to pooled normal plasma (PNP) that is usually used in the performance of a mixing study? a. 1:1 b. 1:4 c. 1:6 d. 1:9

C. A slow acting coagulation inhibitor

What may cause the following mixing studies results? Initial aPTT = 133 seconds 1:1 Mix aPTT pre-incubation = 33 seconds 1:1 Mix aPTT post-incubation = 124 seconds A. Factor IX deficiency B. Factor XI deficiency C. A slow acting coagulation inhibitor D. Factor VII deficiency

b. Increased platelets in the plasma sample

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? a. Residual red blood cells in the plasma sample b. Increased platelets in the plasma sample c. Residual white blood cells in the plasma sample d. Centrifugation time would not affect the detection of lupus anticoagulant in a plasma sample

c. Anti-Xa

When monitoring the use of low-molecular-weight heparins becomes necessary, which of the following laboratory tests is recommended? a. Prothrombin Time (PT) b. Activated partial thromboplastin time (APTT) c. Anti-Xa d. Fibrinogen level

a. Prothrombin

Which of the following is the common name for factor II? a. Prothrombin b. Fibrinogen c. Tissue factor d. Proaccelerin

c. Tissue factor

Which of the following is the common name for factor III? a. Prothrombin b. Fibrinogen c. Tissue factor d. Proaccelerin

d. Proaccelerin

Which of the following is the common name for factor V? a. Prothrombin b. Fibrinogen c. Tissue factor d. Proaccelerin

c. Prothrombin time (PT)/INR

Which of the following laboratory tests is commonly used to monitor oral anticoagulant therapy? a. Activated partial thromboplastin time (APTT) b. Thrombin time (TT) c. Prothrombin time (PT)/INR d. Fibrinogen assay

b. Activated partial thromboplastin time (aPTT)

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? a. Bleeding time b. Activated partial thromboplastin time (aPTT) c. Prothrombin time (PT) d. Factor assays

c. Clotting factors II, VII, IX and X are vitamin K-dependent.

Which of the following statements regarding coagulation disorders is correct? a. Hemophilia A and B are usually acquired disorders. b. Damage to the kidneys can cause hemostatic dysfunction as the kidneys are the primary site for clotting factor production. c. Clotting factors II, VII, IX and X are vitamin K-dependent. d. Factor IX deficiency is the most common inherited coagulation factor deficiency.

b. Mixing studies

Which of the following tests could be used to determine whether an abnormal screening coagulation test result (PT or aPTT) is caused by a factor deficiency or an inhibitor? a. Bleeding time b. Mixing studies c. D-Dimer d. Fibrinogen assay

b. Activated partial thromboplastin time (aPTT)

Which of the following tests is used to monitor therapy with unfractionated heparin? a. Prothrombin time (PT) b. Activated partial thromboplastin time (aPTT) c. Fibrinogen assay d. Platelet function assay

d. Bethesda assay

Which of the following tests is used to quantify a coagulation inhibitor? a. Prothrombin time b. Thrombin time c. Mixing study d. Bethesda assay

d. Russell Viper Venom test

Which of the following tests may be used to confirm screening test results for a lupus anticoagulant (or antiphospholipid antibody)? a. Activated partial thromboplastin time b. Prothrombin time c. Factor assays d. Russell Viper Venom test