Question 1

Heparin therapy is monitored best by performing routine:&#10;A)PT/INRs&#10;B)Anti-factor Xa&#10;C)Fibrinogen levels&#10;D)Bleeding time tests

Accepted Answer

Heparin therapy is best monitored by measuring anti-factor Xa levels, as this directly reflects the inhibition of factor Xa, which is the primary mechanism of action of heparin. PT/INRs are used for monitoring warfarin therapy, not heparin. Fibrinogen levels and bleeding time tests are not specific or sensitive for monitoring heparin therapy.

Question 2

All of the following statements describe factor V Leiden except:&#10;A)It is a cause of activated protein C resistance.&#10;B)It is associated with thrombocytopenia.&#10;C)It is associated with increased risk of thrombosis.&#10;D)Is an inherited disorder.

Accepted Answer

Factor V Leiden is not associated with thrombocytopenia; instead, it is a genetic mutation that leads to increased clotting risk.

Question 3

Antithrombin inhibits all of the following factors except:&#10;A)IIa&#10;B)VIIa&#10;C)IXa&#10;D)XIa

Accepted Answer

Antithrombin primarily inhibits thrombin (factor IIa), factor IXa, and factor XIa, but it does not significantly inhibit factor VIIa.

Question 4

The international normalized ratio (INR) is useful in:&#10;A)The detection of coagulation factor deficiencies&#10;B)Monitoring heparin therapy&#10;C)The detection of inhibitors&#10;D)Monitoring Coumadin therapy

Accepted Answer

The International Normalized Ratio (INR) is primarily used for monitoring the effectiveness of blood-thinning medications such as warfarin (Coumadin), ensuring that patients are receiving the correct dosage to prevent blood clots without significantly increasing the risk of bleeding. It is not used for monitoring heparin therapy, detecting coagulation factor deficiencies, or detecting inhibitors directly.

Question 5

All of the following can cause thrombosis except:&#10;A)Low platelet count&#10;B)Activation of coagulation systems&#10;C)Vascular injury&#10;D)Deficiencies of coagulation inhibitors

Accepted Answer

Low platelet count (thrombocytopenia) does not cause thrombosis; instead, it can lead to bleeding problems. Activation of coagulation systems, vascular injury, and deficiencies of coagulation inhibitors all contribute to thrombosis formation.

Question 6

Which of the following PT results would most likely be seen in a patient who is on Coumadin and is stable?&#10;A)Approximately 26 seconds&#10;B)Approximately 13 seconds&#10;C)Approximately 40 seconds&#10;D)Approximately 60 seconds

Accepted Answer

Coumadin (warfarin) therapy aims to prolong the Prothrombin Time (PT) to about 1.5 to 2.5 times the normal value. A normal PT is usually around 11 to 13.5 seconds, so a PT of approximately 26 seconds indicates effective anticoagulation without excessive risk of bleeding, which is the goal in a stable patient on Coumadin.

Question 7

Heparin-induced thrombocytopenia (HIT) usually:&#10;A)Occurs as a result of protein C deficiency&#10;B)Will show an increase in platelets&#10;C)Occurs 5 to 14 days after heparin therapy&#10;D)Occurs only in males

Accepted Answer

Heparin-induced thrombocytopenia (HIT) typically occurs 5 to 14 days after starting heparin therapy. It is an immune-mediated adverse reaction to heparin that results in a decrease, not an increase, in platelet count. HIT is not related to protein C deficiency and does not occur only in males; it can affect both genders.

Question 8

Protein C is activated by which of the following?&#10;A)Heparin cofactor II&#10;B)Factor VIIIa&#10;C)Antithrombin&#10;D)Protein S

Accepted Answer

Protein C is activated by Protein S. Protein S serves as a cofactor to Protein C in the inactivation of Factors Va and VIIIa, which are crucial steps in the regulation of blood coagulation.

Question 9

All of the following statements are true regarding Coumadin except:&#10;A)It is a vitamin K antagonist.&#10;B)It needs antithrombin as a cofactor.&#10;C)PT is used to monitor its dosage.&#10;D)It is not recommended for pregnant and lactating women.

Accepted Answer

Coumadin (warfarin) works by inhibiting the synthesis of vitamin K-dependent clotting factors, not by requiring antithrombin as a cofactor. PT (Prothrombin Time) is indeed used to monitor its dosage, and it is contraindicated in pregnant and lactating women due to its ability to cross the placenta and its presence in breast milk, potentially causing bleeding in the fetus or nursing infant.

Question 10

Factor Xa inhibitors are monitored using which assay?&#10;A)APTT&#10;B)PT&#10;C)anti-factor Xa assay&#10;D)platelet count

Accepted Answer

Factor Xa inhibitors are monitored using the anti-factor Xa assay, which directly measures the activity of factor Xa in the blood.

Question 11

Heparin:&#10;A)Inhibits PF3&#10;B)Inhibits thrombin&#10;C)Degrades antithrombin&#10;D)Forms a complex with protein C

Accepted Answer

The answer of Heparin:&#10;A)Inhibits PF3&#10;B)Inhibits thrombin&#10;C)Degrades antithrombin&#10;D)Forms a complex with...

Question 12

The target therapeutic range for an INR in patients with thromboembolic disease is:&#10;A)1 to 2&#10;B)1.5 to 2.5&#10;C)2 to 3&#10;D)2 to 2.5

Accepted Answer

The answer of The target therapeutic range for an INR...

Question 13

Which test should be ordered as a baseline before started heparin therapy on a patient?&#10;A)PT&#10;B)Platelet count&#10;C)APTT&#10;D)Fibrinogen

Accepted Answer

The answer of Which test should be ordered as a...

Question 14

What is the term for the condition that predisposes patients to thrombosis?&#10;A)Thrombopenia&#10;B)Thrombophilia&#10;C)Thrombocytosis&#10;D)Anemia

Accepted Answer

The answer of What is the term for the condition...

Question 15

Arterial thrombosis is associated with:&#10;A)Antithrombin deficiency&#10;B)Protein S deficiency&#10;C)Protein C deficiency&#10;D)Both protein S and C deficiencies

Accepted Answer

The answer of Arterial thrombosis is associated with:&#10;A)Antithrombin deficiency&#10;B)Protein S...

Question 16

All of the following are naturally occurring thrombin inhibitors except:&#10;A)AT&#10;B)Prothrombin cofactor II&#10;C)Protein C&#10;D)Plasmin

Accepted Answer

The answer of All of the following are naturally occurring...

Question 17

The most common tests used to detect lupus anticoagulants include all of the following except:&#10;A)aPTT&#10;B)Kaolin clotting time&#10;C)PT/INR&#10;D)Dilute Russell viper venom test

Accepted Answer

The answer of The most common tests used to detect...

Question 18

Drug alternatives for patients with heparin-induced thrombocytopenia include:&#10;A)Danaparoid&#10;B)Warfarin&#10;C)Streptokinase&#10;D)Aspirin

Accepted Answer

The answer of Drug alternatives for patients with heparin-induced thrombocytopenia...

Question 19

Coumadin acts in such a way that it:&#10;A)Alters the synthesis of vitamin K-dependent factors&#10;B)Reduces the circulating level of factors III and V&#10;C)Reduces the circulating level of factor I&#10;D)Cleaves carboxyreductase to generate glutamic acid

Accepted Answer

The answer of Coumadin acts in such a way that...

Question 20

The lupus anticoagulant is directed against:&#10;A)Factor VIII&#10;B)Factor X&#10;C)Factor IX&#10;D)Phospholipids

Accepted Answer

The answer of The lupus anticoagulant is directed against:&#10;A)Factor VIII&#10;B)Factor...

Deck 19: Introduction to Thrombosis and Anticoagulant Therapy