Haemostasis V: Thrombotic Disorders (DVT, Pulmonary Embolism) Flashcards
(35 cards)
What is thrombophilia?
Thrombophilia is a genetically determined increased likelihood of thrombosis.
What is the incidence of venous thromboembolism?
The incidence of venous thromboembolism is approximately 1 per 1000 annually.
Which thrombotic disorder commonly arises from proximal DVT?
Most pulmonary emboli arise from proximal DVT in the popliteal, femoral, and iliac veins.
Name three common forms of thrombophilia.
Common forms of thrombophilia include Factor V Leiden, Prothrombin G20210A, and increased VIII levels.
Name two rare forms of thrombophilia.
Rare forms of thrombophilia include Protein C deficiency and Protein S deficiency.
What are the clinical features of DVT with gangrene?
Clinical features of DVT with gangrene include swelling, erythema, and discoloration.
What are the objectives of treatment for venous thromboembolism?
The objectives of treatment are to prevent death from pulmonary embolism, prevent morbidity from venous thromboembolism, and minimize post-thrombotic syndrome.
What imaging modality is used to diagnose DVT?
Doppler ultrasonography is used to diagnose DVT.
What are the steps in the diagnosis of DVT?
Diagnosis of DVT involves clinical history and examination, Doppler ultrasonography, venography, plasma D-dimer, clotting profile, chest USS, spiral CT, pulmonary angiography, and tests for thrombophilias.
Name three treatment options for anticoagulant therapy.
Treatment options include standard heparin (UFH), low molecular weight heparin, and oral anticoagulants.
What is the role of an inferior vena cava filter in thrombosis management?
An inferior vena cava filter is used in patients with acute DVT who have an absolute contraindication for anticoagulation.
What is the function of fibrinolysis?
Fibrinolysis plays a role in the dissolution of blood clots and maintenance of a patent vascular system.
What is plasminogen converted into during fibrinolysis?
Plasminogen is converted into plasmin during fibrinolysis.
What is the function of plasmin?
Plasmin degrades fibrin into soluble fibrin degradation products (FDPs).
Name two physiological activators of plasminogen.
tPA (tissue plasminogen activator) and uPA (urokinase plasminogen activator) are physiological activators of plasminogen.
How does streptokinase function in fibrinolysis?
Streptokinase forms a 1:1 complex with plasminogen, causing a conformational change that activates plasminogen to plasmin.
What is the dosage protocol for streptokinase in myocardial infarction?
The dosage protocol for streptokinase in MI is 1.5 million units IV over 30–60 minutes.
What enzyme directly converts plasminogen to plasmin?
Urokinase directly converts plasminogen to plasmin.
Why is urokinase not immunogenic?
Urokinase is not immunogenic because it does not cause an immune response.
What are the limitations of urokinase availability?
Urokinase has limited availability.
How does rt-PA (alteplase) preferentially activate plasminogen?
Rt-PA (alteplase) preferentially activates plasminogen in the presence of fibrin, reducing systemic lytic states.
What is the dosage protocol for rt-PA in acute myocardial infarction?
The dosage protocol for rt-PA in acute MI is 15 mg IV bolus, followed by 50 mg IV infusion over 30 minutes, then 35 mg over 60 minutes.
What is the dose adjustment for rt-PA in patients weighing less than 65 kg?
The dose adjustment for rt-PA in patients under 65 kg is a reduced total dose.
Name one contraindication for rt-PA use in elderly patients.
Rt-PA is contraindicated in elderly patients over 80 years old.
