Term
| Which tests can be used to detect qualitative defects in platelets if the count is NORMAL (such as in vonWillibrand or Glanzmann thrombasthenia)? |
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Definition
| Bleeding Time, Platelet Function Test, or Platelet Aggregometry |
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Term
| What converts fibrinogen to fibrin? |
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Definition
Thrombin
-The active enzyme derived from Prothrombin (Factor II). It converts fibrinogen to fibrin. |
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Term
| How does aspirin interfere with clotting? |
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Definition
| It prevents platelet aggregation by inhibiting the enzyme cyclooxygenase thus preventing thromboxane A2 formation from platelet arachadonic acid. |
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Term
| What are the components in the PT reagent and what is the purpose of each? |
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Definition
Rabbit thromboplastin acts as tissue Factor III to activate factor VII to start the EXTRINISIC System.
Calcium in the thromboplastin adds back the Calcium bound by the Sodium Citrate anticoagulant in the collection tube. |
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Term
| What are the reagents used in the PTT and what is the purpose of each? |
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Definition
| Activated partial thromboplastin (Actin) contains a commercial phospholipid and a Negatively charged particle, like Kaolin o ellagic acid, to active Factor XII to start the INTRINSIC System. CaCl2 adds back the Calcium bound by the Sodium Citrate anticoagulant in the collection tube. |
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Term
| What is the proper type and concentration of anticoagulant used in collection tubes for coagulation? |
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Definition
|
|
Term
| What is the correct blood to anticoagulant ratio in collection tubes for coagulation? |
|
Definition
| 9 parts blood to 1 part anticoagulant. |
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Term
| What are the roles of protein C, protein S, and antithrombin? |
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Definition
| All are inhibitors to clotting, thus preventing excess clotting that may occur. |
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Term
| A deficiency of Protein C, Protein S, or Antithrombin will result in what type of disorder? |
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Definition
| A deficiency in any of the three will cause the patient to form excess blood clots or thrombosis. |
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|
Term
| Explain the Leiden Mutation including clinical features. |
|
Definition
| Patients with this mutation are resistant to Protein C inhibiting factors Va & VIIIa. This is the most common genetic thrombophilia and causes excess blood clotting. |
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Term
|
Definition
| Abnormal excess thrombosis. |
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|
Term
| Lupus anticoagulants are SCREENED for by what tests? |
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Definition
| Mixing studies Not Correcting a Prolonged PTT |
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|
Term
| Lupus anticoagulants are CONFIRMED by what tests? |
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Definition
-Platelet Neutralization Procedure (PNP)
-Dilute Russell's Viper Venom Test (DRVVT)
-Anti-Phospholipid Assay |
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Term
| With Coumadin, what is the therapeutic range for PT? |
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Definition
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|
Term
| Coumadin is an antagonist to _____ _____ factors. |
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Definition
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|
Term
| With Heparin, what is the therapeutic range for PTT? |
|
Definition
|
|
Term
| Heparin prevents future clots by binding to ________. |
|
Definition
|
|
Term
True or False:
If ATIII is deficient, Heparin would NOT be therapeutic. |
|
Definition
|
|
Term
True or False:
Heparin works immediately? |
|
Definition
|
|
Term
| Coumadin must be administered orally. How long does it take before it begins to work? |
|
Definition
|
|
Term
True or False:
You can not use coagulation testing on serum. |
|
Definition
|
|
Term
| What is the major activator of the fibrinolytic system? |
|
Definition
|
|
Term
| What substance starts the clotting process? |
|
Definition
|
|
Term
| What test is abnormal in Factor XIII Deficiency? |
|
Definition
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