Coagulation Disorders

Question 1

Thrombocytopenia

Answer 1

Causes are related to:
Decreased production (leukemia, myelodysplastic syndrome, aplastic anemia)

Increased destruction (Idiopathic thrombocytopenic purpura (ITP), Thrombotic thrombocytopenic purpura (TTP), Hemolytic-uremic syndrome, Disseminated intravascular coagulation)

Medication-induced

Question 2

Factor V Leiden Mutation

Answer 2

Most common genetic hypercoagulable state

Resistant to normal inactivation (by protein C); predispose to venous thrombosis

Suspect with recurrent thromboembolic events, thromboembolism in a young patient or in a patient with no risk factors

Diagnosed by activated protein C resistance assay with genetic testing being definitive

Treatment is with anticoagulation

Question 3

Antiphospholipid Syndrome

Answer 3

Antibodies to phospholipid-binding proteins (CLOT)

Associated with SLE

(+) Lupus anticoagulant, (+) Anticardiolipin antibody, (+) Anti-β2 glycoprotein-I Elisa

Question 4

Heparin-induced thrombocytopenia (HIT)

Answer 4

≥ 50 % reduction in platelet count within 7-10 days of exposure to heparin

Results in global thrombocytopenia and thromboembolism due to immune reaction with platelet factor

Treatment: stop all heparin, give a direct thrombin inhibitor instead

Question 5

Von Willebrand Disease (vWD)

Answer 5

Most common genetic bleeding disorder, autosomal dominant

Platelets cannot adhere to the vessel wall at the site of an injury. (increased bleeding time)

Question 6

↓von Willebrand’s factor (vWF) and ↓ Factor VIII

Patients may present with ___?

Answer 6

excessive bleeding after a cut, or increased menstrual bleeding.

Differs from hemophilia: lack of hemarthrosis, small amounts of superficial bleeding, common to have bleeding with minor injury and petechiae.

Question 7

Von Willebrand Disease (vWD) treatment

Answer 7

DDAVP (desmopressin)

Excessive bleeding: transfusion of concentrated blood clotting factors containing von Willebrand factor

Question 8

Hemophilia is a hereditary bleeding disorder caused by a deficiency in one of two blood clotting factors: ___

Answer 8

factor VIII or factor IX.

Question 9

• prolonged aPTT and normal platelet count and function
• accounts for about 80% of all cases
• deficiency in clotting factor VIII

Answer 9

hemophilia A

Question 10

deficiency in clotting factor IX

Answer 10

hemophilia B

Remember: Hemophilia A = “Aight” and B comes after A which is factor NINE