Term
Name mediators of each step of primary hemostasis:
1) transient vasoconstriction
2) Platelet adhesion
3) Platelet degranulation
4) Platelet aggregation |
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Definition
1) Endothelin & neural reflex
2) vWF binding subendothelial collagen --> Gp1b binding vWF
3) ADP --> Gp2b/3a expression; TXA2 --> platelet aggregation
4) Gp2b/3a binds fibrinogen |
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Term
| what 2 substances do Weibel-Palade bodies contain? |
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Definition
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Term
| What type of bleeding occurs w/ primary hemostais defect? Secondary? |
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Definition
primary = bleeding into skin; mucosal bleeds (e.g. epistaxis, GI bleeds, menorrhagia)
secondary = bleeding into muscle & joints |
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Term
| Petechiae are seen with qualitative platelet disorders? |
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Definition
| no. Petechiae are seen with platelet counts <50K, but not with qualitative platelet disorders (e.g. glazmann, aspirin, uremia) |
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Term
| Qualitative platelet disorder with large platelets |
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Definition
| Bernard Soulier ("big suckers"); Gp1b deficiency |
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Term
| Autoantibody in ITP? Treatment for ITP? |
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Definition
Antibody against GpIIb/IIIa
Tx may consist of:
- Corticosteroids --> decrease anti Gp2b/3a production;
- IVIG --> redirects splenic activity against infused Ig rather than autoreactive Ig (transient efficacy, allows for platelet recovery if very low);
- Splenectomy --> remove source of antibodies & platelets (only in refractory cases) |
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Term
Scenario 1:
Thrombocytopenia in children a few weeks after a viral infection or immunization. Self-limiting, resolving w/in weeks of presentation.
Scenario 2:
Thrombocytopenia arising in woman of childbearing age. May be primary or secondary (e.g. SLE). May cause short-lived thrombocytopenia in child |
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Definition
Acute ITP
Chronic ITP. Transient thrombocytopenia is child is due to placental transfer of IgG against Gp1b
platelet counts are usually <50K. PT/aPTT are normal. There are increased megakaryocytes in bone marrow |
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Term
What laboritory finding do you have in microangiopathic hemolytic anemias (i.e. HUS & TTP) that you don't have in ITP?
Hint: look at blood smear |
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Definition
schistocytes (aka helmet cells)
Both conditions have thrombocytopenia, normal PT/aPTT, and increased megakaryocytes in bone marrow |
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Term
What activates:
1) Factor VII (extrinsic pathway)
2) Factor XII (intrinsic pathway) |
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Definition
1) Tissue thromboplastin
2) Subendothelial collagen
Other factors needed for activation of clotting cascade: phospholpid surface & calcium ions |
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Term
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Definition
Direct thrombin inhibitors (e.g. lepirudin, argatroban)
Never give warfarin/coumadin b.c. in HIT, the risk for Warfarin/coumadin induced skin necrosis is greatly enhanced |
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Term
give etiology of DIC for each of the following causes:
1) obstetric complication
2) Sepsis
3) Adenocarcinoma
4) APL
5) Rattlesnake bite |
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Definition
1) Amniotic fluid contains tissue thromboplastin --> activates extrinsic pathway
2) Endotoxins (esp E.coli & N.meningitidis) & cytokines (TNF & IL1) induce endothelial cells to make tissue factor
3) Mucin
4) primary granules
5) venom |
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Term
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Definition
1) cleaves fibrin & fibrinogen in plasma
2) destroys coagulation factors
3) prevents platelet aggregation |
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Term
Etiology of defective fibrinolysis in each disorder:
1) radical prostatectomy
2) Cirrhosis
What distinguishes abnormal fibrinolysis from DIC? |
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Definition
1) release of urokinase --> plamin activation
2) Loss of liver production of alpha2-antiplasmin
abnormal fibrinolysis is distinguished from DIC by D-dimers. D-dimers are only present in DIC, but fibrinogen split products are increased in both cases |
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Term
| Treatment for overactive plasmin? |
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Definition
| aminocaproic acid: lysine analog that will bind plasmin & prevent it from interacting w/ fibrinogen |
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Term
| Atherosclerosis, vasculitis, & high homocysteine levels all lead to increased risk for thrombosis via... |
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Definition
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Term
| What does thrombomodulin do? (secreted by endothelium) |
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Definition
| binds thrombin & directs it to activate protein C instead of factors V & VIII --> anticoagulant effects |
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Term
| vessel thrombosis, mental retardation & marfanoid habitus. A metabolic disorder |
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Definition
| Cystathionine beta synthase (CBS) deficiency results in high homocyteine levels w/ homocytinuria |
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Term
| person with recurrent DVTs or DVT @ young age & is at increased risk for warfarin skin necrosis |
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Definition
| Protein C or S deficiency (AD) |
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Term
| person is given heparin & there is no rise in aPTT |
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Definition
| ATIII deficiency; Tx by giving high dose of heparin to activate limited ATIII & warfarin --> continue person on warfarin |
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Term
| how do OCPs increase risk for thrombosis? |
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Definition
| Induces increased production of coagulation factors |
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Term
List characteristic finding for each type of embolus:
1) Thromboembolus (most common, >90%)
2) Atheroembolus (atherosclerotic plaque breaks off)
3)Fat embolus (e.g. following fracture)
4) Caisson disease
5) Amniotic fluid embolus |
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Definition
1) Lines of zahn
2) Cholesterol clefts
3) Fat, often w/ bone marrow elements
4) gas
5) Squamous cells & keratin debris (from baby) |
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Term
| Is D-dimer elevated in pulmonary embolism? |
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Definition
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