Question 1

Which unusual laboratory finding may be present in sepsis-induced DIC?

Accepted Answer

A)  Fibrinogen may be high because it is an acute phase reactant. 
B)  Schistocytes are absent because the fever destroys them. 
C)  D dimer is low because the toxins prevent fibrin lysis. 
D)  The PT and PTT are low because bacteria interfere with these tests. 
A)  Fibrinogen may be high because it is an acute phase reactant. 
B)  Schistocytes are absent because the fever destroys them. 
C)  D dimer is low because the toxins prevent fibrin lysis. 
D)  The PT and PTT are low because bacteria interfere with these tests. A

Question 2

Inappropriate formation of platelets or fibrin clots that obstructs blood vessels is called:

Accepted Answer

A)  Thrombophilia 
B)  Thrombosis 
C)  Embolus 
D)  Factor V Leiden 
A)  Thrombophilia 
B)  Thrombosis 
C)  Embolus 
D)  Factor V Leiden B

Question 3

When the chromogenic assay for antithrombin is performed, which of the following is true?

Accepted Answer

A)  The colored end-product intensity is inversely proportional to the antithrombin concentration. 
B)  The chromogenic substrate is bound by antithrombin. 
C)  Warfarin is added to the patient sample before testing to improve sensitivity. 
D)  Activated protein C competes for the chromogenic substrate, so it must first be selectively removed. 
A)  The colored end-product intensity is inversely proportional to the antithrombin concentration. 
B)  The chromogenic substrate is bound by antithrombin. 
C)  Warfarin is added to the patient sample before testing to improve sensitivity. 
D)  Activated protein C competes for the chromogenic substrate, so it must first be selectively removed. A

Question 4

A patient arrives at the emergency department complaining of pain in the calf of his left leg and shortness of breath. A "stat" D dimer is ordered. Why is this useful information for this patient's care?

Accepted Answer

A)  An elevated D dimer supports the possibility of deep vein thrombosis. 
B)  An elevated D dimer is diagnostic for deep vein thrombosis. 
C)  A normal D dimer is diagnostic for deep vein thrombosis. 
D)  This was not an appropriate test to order on this patient. 
A)  An elevated D dimer supports the possibility of deep vein thrombosis. 
B)  An elevated D dimer is diagnostic for deep vein thrombosis. 
C)  A normal D dimer is diagnostic for deep vein thrombosis. 
D)  This was not an appropriate test to order on this patient.

Question 5

Why does the factor V Leiden mutation increase thrombotic risk?

Accepted Answer

A)  Makes factor Va resistant to degradation by activated protein C 
B)  Makes blood more viscous 
C)  Makes factor V more susceptible to activation by thrombin 
D)  Decreases the binding of factor Va to the inhibitor antithrombin 
A)  Makes factor Va resistant to degradation by activated protein C 
B)  Makes blood more viscous 
C)  Makes factor V more susceptible to activation by thrombin 
D)  Decreases the binding of factor Va to the inhibitor antithrombin

Question 6

What tests should be performed on a regular basis on patients receiving therapeutic heparin?

Accepted Answer

A)  PT and hematocrit 
B)  PTT and white count 
C)  PTT and platelet count 
D)  Factor assays and platelet count 
A)  PT and hematocrit 
B)  PTT and white count 
C)  PTT and platelet count 
D)  Factor assays and platelet count

Question 7

A 37-year-old female patient has a PTT of 76 seconds (reference range, 25 to 37 seconds). Her plasma is mixed 1:1 with normal plasma. An immediate PTT performed on the mix is 74 seconds. Which of the following is the most likely diagnosis?

Accepted Answer

A)  Hemophilia A 
B)  Factor VIII inhibitor 
C)  Intrinsic factor deficiency 
D)  Lupus anticoagulant 
A)  Hemophilia A 
B)  Factor VIII inhibitor 
C)  Intrinsic factor deficiency 
D)  Lupus anticoagulant

Question 8

A patient has a quantitative D dimer of 800 ng/mL. Which can be ruled out from the following list?

Accepted Answer

A)  DIC 
B)  Deep vein thrombosis 
C)  Pulmonary embolus 
D)  Patient is normal 
A)  DIC 
B)  Deep vein thrombosis 
C)  Pulmonary embolus 
D)  Patient is normal

Question 9

What is the most common congenital disorder of excess thrombosis in whites?

Accepted Answer

A)  Protein S deficiency 
B)  Antithrombin deficiency 
C)  Activated protein C resistance 
D)  DIC 
A)  Protein S deficiency 
B)  Antithrombin deficiency 
C)  Activated protein C resistance 
D)  DIC

Question 10

Why does prothrombin G20210A increase the risk of thrombosis?

Accepted Answer

A)  Makes prothrombin activation easier 
B)  Elevates prothrombin levels 
C)  Decreases binding of thrombin by antithrombin 
D)  Decreases binding of plasminogen to prothrombin 
A)  Makes prothrombin activation easier 
B)  Elevates prothrombin levels 
C)  Decreases binding of thrombin by antithrombin 
D)  Decreases binding of plasminogen to prothrombin

Question 11

Which of the following is an expected finding in DIC?

Accepted Answer

A)  Elevated D-dimer and fibrin split products 
B)  High platelet count 
C)  Low prothrombin time (PT) and PTT 
D)  Low TT 
A)  Elevated D-dimer and fibrin split products 
B)  High platelet count 
C)  Low prothrombin time (PT) and PTT 
D)  Low TT

Question 12

Select the next best test to run given the following PTT results on a patient's plasma:

Accepted Answer

A)  Dilute Russell's viper venom time 
B)  Factor assays 
C)  Factor V Leiden 
D)  Bethesda titer 
A)  Dilute Russell's viper venom time 
B)  Factor assays 
C)  Factor V Leiden 
D)  Bethesda titer

Question 13

What is the best method to prevent warfarin-induced skin necrosis during treatment for thrombosis?

Accepted Answer

A)  Use higher dose of warfarin early in treatment. 
B)  Give the patient injections of protein C. 
C)  Stop warfarin at the first sign of necrosis. 
D)  Use heparin for first 5 days in conjunction with warfarin. 
A)  Use higher dose of warfarin early in treatment. 
B)  Give the patient injections of protein C. 
C)  Stop warfarin at the first sign of necrosis. 
D)  Use heparin for first 5 days in conjunction with warfarin.

Question 14

What is important about the test systems used for detection of the lupus anticoagulant?

Accepted Answer

A)  The phospholipid concentration should be high. 
B)  Ellagic acid should be the PTT activator substance. 
C)  The patient plasma and normal plasma used for mixing studies should be platelet poor. 
D)  A 1:1 mix should be performed when the initial test is normal to improve the sensitivity. 
A)  The phospholipid concentration should be high. 
B)  Ellagic acid should be the PTT activator substance. 
C)  The patient plasma and normal plasma used for mixing studies should be platelet poor. 
D)  A 1:1 mix should be performed when the initial test is normal to improve the sensitivity.

Question 15

Which of the following results puts the patient at an increased risk for thrombosis?

Accepted Answer

A)  Total cholesterol of 180 mg/dL 
B)  PTT of 25 seconds 
C)  Deficiency of factor V 
D)  Chronically elevated fibrinogen 
A)  Total cholesterol of 180 mg/dL 
B)  PTT of 25 seconds 
C)  Deficiency of factor V 
D)  Chronically elevated fibrinogen

Question 16

What is used to activate protein C in the chromogenic assay used to determine its concentration?

Accepted Answer

A)  Partial thromboplastin 
B)  A specific snake venom 
C)  Kaolin 
D)  Heparin 
A)  Partial thromboplastin 
B)  A specific snake venom 
C)  Kaolin 
D)  Heparin

Question 17

Which of the following is an expected finding in DIC?

Accepted Answer

A)  Thrombocytosis 
B)  Schistocytes on the blood film 
C)  Normal hemoglobin and hematocrit 
D)  Macrocytic red cells 
A)  Thrombocytosis 
B)  Schistocytes on the blood film 
C)  Normal hemoglobin and hematocrit 
D)  Macrocytic red cells

Question 18

A patient who is not on heparin and has no history of a factor deficiency has a prolonged partial thromboplastin time (PTT). Select the test that should be performed next.

Accepted Answer

A)  High-sensitivity C-reactive protein 
B)  Mixing studies for lupus anticoagulant 
C)  Thrombin time (TT) 
D)  Lipid panel 
A)  High-sensitivity C-reactive protein 
B)  Mixing studies for lupus anticoagulant 
C)  Thrombin time (TT) 
D)  Lipid panel

Question 19

Which of the following is the cause for most strokes and heart attacks in the United States?

Accepted Answer

A)  Hemorrhage 
B)  Thrombocytopenia 
C)  Cancer 
D)  Consequences of thrombotic events 
A)  Hemorrhage 
B)  Thrombocytopenia 
C)  Cancer 
D)  Consequences of thrombotic events

Question 20

A thrombosis risk testing profile is ordered on a patient being treated with warfarin for a blood clot in the leg. Select the best course of action.

Accepted Answer

A)  Run the tests immediately. 
B)  Reject the order. 
C)  Perform only the tests for protein C and protein S. 
D)  Recommend the testing be postponed until the warfarin is discontinued. 
A)  Run the tests immediately. 
B)  Reject the order. 
C)  Perform only the tests for protein C and protein S. 
D)  Recommend the testing be postponed until the warfarin is discontinued.

Exam 42: Thrombosis Risk Testing

Which unusual laboratory finding may be present in sepsis-induced DIC?

Inappropriate formation of platelets or fibrin clots that obstructs blood vessels is called:

When the chromogenic assay for antithrombin is performed, which of the following is true?

A patient arrives at the emergency department complaining of pain in the calf of his left leg and shortness of breath. A "stat" D dimer is ordered. Why is this useful information for this patient's care?

Why does the factor V Leiden mutation increase thrombotic risk?

What tests should be performed on a regular basis on patients receiving therapeutic heparin?

A 37-year-old female patient has a PTT of 76 seconds (reference range, 25 to 37 seconds). Her plasma is mixed 1:1 with normal plasma. An immediate PTT performed on the mix is 74 seconds. Which of the following is the most likely diagnosis?

A patient has a quantitative D dimer of 800 ng/mL. Which can be ruled out from the following list?

What is the most common congenital disorder of excess thrombosis in whites?

Why does prothrombin G20210A increase the risk of thrombosis?

Which of the following is an expected finding in DIC?

Select the next best test to run given the following PTT results on a patient's plasma:

What is the best method to prevent warfarin-induced skin necrosis during treatment for thrombosis?

What is important about the test systems used for detection of the lupus anticoagulant?

Which of the following results puts the patient at an increased risk for thrombosis?

What is used to activate protein C in the chromogenic assay used to determine its concentration?

Which of the following is an expected finding in DIC?

A patient who is not on heparin and has no history of a factor deficiency has a prolonged partial thromboplastin time (PTT). Select the test that should be performed next.

Which of the following is the cause for most strokes and heart attacks in the United States?

A thrombosis risk testing profile is ordered on a patient being treated with warfarin for a blood clot in the leg. Select the best course of action.

An Overview of Clinical Laboratory Hematology

Safety in the Hematology Laboratory

Specimen Collection

Care and Use of the Microscope

Quality Assurance in Hematology and Hemostasis Testing

Cellular Structure and Function

Hematopoiesis

Erythrocyte Production and Destruction

Energy Metabolism and Membrane Physiology of the Erythrocyte

Hemoglobin Metabolism

Iron Metabolism

Leukocyte Development, Kinetics, and Functions

Platelet Production, Structure, and Function

Routine and Point-Of-Care Testing in Hematology: Manual and Semiautomated Methods

Examination of the Peripheral Blood Film and Correlation With the Complete Blood Count

Bone Marrow Examination

Body Fluids in the Hematology Laboratory

Anemias: Red Blood Cell Morphology and Approach to Diagnosis

Disorders of Iron and Heme Metabolism

Anemias Caused by Defects of Dna Metabolism

Bone Marrow Failure

Introduction to Increased Destruction of Erythrocytes

Intrinsic Defects Leading to Increased Erythrocyte Destruction

Extrinsic Defects Leading to Increased Erythrocytedestructionnonimmune Causes

Extrinsic Defects Leading to Increased Erythrocytedestructionimmune Causes

Hemoglobinopathies Structural Defects in Hemoglobin

Thalassemias

Nonmalignant Leukocyte Disorders

Introduction to Leukocyte Neoplasms

Cytochemistry

Cytogenetics

Molecular Diagnostics in the Clinical Laboratory

Flow Cytometric Analysis in Hematologic Disorders

Myeloproliferative Neoplasms

Myelodysplastic Syndromes

Acute Leukemias

Mature Lymphoid Neoplasms

Pediatric and Geriatric Hematology

Automated Cell-Counting Instrumentation

Normal Hemostasis and Coagulation

Hemorrhagic Coagulation Disorders

Thrombocytopenia and Thrombocytosis

Qualitative Disorders of Platelets and Vasculature

Laboratory Evaluation of Hemostasis

Monitoring Antithrombotic Therapies

Coagulation Instrumentation

Filters