BLEEDING AND THROMBOTIC DISORDERS Flashcards
This deck covers bleeding and thrombotic disorders
What’s your diagnosis?
Child
Abrupt onset of petechiae/ecchymoses around 1-2 weeks after viral illness
BT-Prolonged
Platelet count- low
PT- normal
PTT- normal
The bone marrow aspirate shows an increase in immature megakaryocytes
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Acute immune thrombocytopenic purpura (ITP)
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Vitamin K dependent coagulation factors
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II, VII, IX and X
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- Inherited thrombotic disorder caused by replacement of arginine by glutamine at position 506.
- Which coagulation factor levels are increased in this disorder as a result of the single base change?
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- Factor V Leiden
- Factor Va
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List the causes for DIC
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STOP Making Thrombi
- Sepsis (gram negative)
- Trauma
- Obstetric complications
- Pancreatitis
- Malignancy
- Transfusion
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List some antiphospholipid antibodies
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anticardiolipin antibodies
anti-β2-glycoprotein antibodies
lupus anticoagulants
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- Does heparin prolong PT or PTT ?
- How?
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- Prolongation of PT and PTT
Gotcha ;)
- Heparin activates ATIII- this in turn inhibits both sides of the coagulation cascade – VIIa, IXa, Xa, XIa and thrombin
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A 56 year old female with atrial fibrillation is started on a drug. 2 days later , she develops a lesion on her left lower limb as seen below. PT is prolonged.
1. What is the reason for the development of the lesion?
2. If this woman had an inherited Protein C deficiency, would she have a greater risk of developing this lesion?
Deborah Dalmeida MD
- Warfarin induced skin necrosis
- Protein C together with Factor VII has the shortest half life (6 and 14 hours respectively). In normal individuals, the fall in protein C activity following the start of warfarin is generally not of clinical significance, but in heterozygotes with levels of protein C that are about half of normal, a further drop in protein C activity during the first day of therapy can trigger thrombosis in the skin.
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Following platelet activation, Glycoprotein IIb/IIIa located on the surface of a platelet is able to cross link with another platelet via binding to which substance?
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Fibrinogen
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dyspnea, acute renal failure
BT-prolonged
Platelet count- Low
PT- Prolonged
PTT-Prolonged
Fibrinogen- decreased1.
1.Diagnosis?
2. Most sensitive screen?
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- DIC
- Elevated D-Dimers
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1. Diagnosis?
Neurologic symptoms
Fever
Kidney Failure
BT-Prolonged
Platelet count- Low
PT- Normal
PTT- Normal
2. Etiology?
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- Thrombotic Thrombocytopenic Purpura (TTP)
- Deficiency of ADAMTS13
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How does heparin cause life threatening thrombosis?
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- large complexes of IgG, PF4, and heparin detach from platelets, , attach to endothelial cells, and damage the endothelial cells, causing activation of the coagulation system
- Enhances AT III’s affinity for thrombin, IXa,Xa, XIa and XIIa
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glomerular capillaries occluded by microthrombi
renal failure
Schistocytes on a peripheral smear
BT- Prolonged
Platelet count- Low
PT- Normal
PTT- Normal
history of bloody diarrhea after eating an undercooked hamburger at a restaurant
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HUS
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2 properties of antiphospholipid antibodies
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a. Bind to phospholipid surface
b. bind to the phospholipid part of the PTT reagent
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Bernard Soulier/ vW disease?
BT- Prolonged
Platelet count-Low
PT- Normal
PTT- Normal
reduced ristocetin cofactor activity which does not normalize after the addition of normal plasma
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Bernard-Soulier syndrome
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superficial bleeding localized to skin and mucous membranes
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Purpura
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