Hemostasis Flashcards Preview

Unit 2 > Hemostasis > Flashcards

Flashcards in Hemostasis Deck (15):
1

Immune thrombocytopenic Purpura (ITP)

Autoimmune production of IgG against platelet antigens. Most common cause of thrombocytopenia. Usually acute in children after immunization but crhonic in women of childbearing age.

↓platelet count
Normal PT/PTT
↑megakaroyocytes
Treat with steroids, IVIG and splenectomy

2

Thrombocytopenic Purpura (TTP)

Decreased ADAMTS13 an enzyme that cleaves vWF multimers to allow for eventual degradation.

Skin and mucosal bleeding
MAHA
Fever
Renal insufficiency (more commone in HUS)
CNS abnormalities (more common in TTP)
Microthrombi
Shistocytes (Anemia)
↓platelet count
Normal PT/PTT
Treat with plasmapherisis and corticosteroids

3

Hemolytic Uremic Syndrome

Seen in children with Ecoli O157:H7 dysentery from undercooked beef. Leads to reduction in ADAMTS13 due to E.coli toxin.

Skin and mucosal bleeding
MAHA
Fever
Renal insufficiency (more commone in HUS)
CNS abnormalities (more common in TTP
Shistocytes
Microthrombi
↓platelet count
Normal PT/PTT
Treat with plasmapherisis and corticosteroids

4

Bernard Soulier Syndrome

GPIb deficiency which stops platelet adhesion.

Autosomal recessive
Skin and mucosal bleeding
↓platelet count, prolonged bleeding time
Enlarged platelets (new and young)

5

Glanzmann thrombasthenia

GPIIb/IIIa deficiency which stops platelet aggregation.

Autosomal recessive
Skin and mucosal bleeding
Prolonged bleeding time, normal platelet count
Enlarged platelets (new and young)

6

Hemophilia A

Genetic FVIII deficiency

X-linked recessive or spontaneous mutation
Deep tissue bleeding
Re-bleeding after surgical practices
↑PTT; normal PT
↓FVIII
Normal platelet count and bleeding time

7

Hemophilia B (Christmas Disease)

Genetic IX deficiency

X-linked recessive
Deep tissue bleeding
Re-bleeding after surgical practices
↑PTT; normal PT
↓IX
Normal platelet count and bleeding time

8

Von Willebrand Disease

enetic vWF deficiency. Most common inherited coagulation disorder. vWF helps stabilize FVIII.

Autosomal Dominant
↓vWF
Mild mucosal and skin bleeding
↑PTT; normal PT
Increased bleeding time
Abnormal ristocetin test

Treatment: Give desmopressin (stimulates vWF release from endothelial cells)

9

Heparin Induced Thrombocytopenia: Platelet destruction after heparin therapy causes an aggregation of platlets.

Increased Thrombosis

10

Disseminated Intravascular Coagulation:

Caused by MOIST (Malignancy, Obstetric complications, Infectsion, Sepsis, Snake Bites, Trauma and Transfusion) as well as NP (Nephrotic syndrome, Pancreatitis). Consumption of platelets to make microthrombi. Treat by addressing underlying causes and transfusing blood products.

Use of all clotting factors to form microthrombi
↓Platelet count
↑PT/PTT (coagulation factors all used up)
↓fibrinogen
↑ fibrin and D-dimer because aggregations come and go

11

Protein C or S Deficiency

Decreased negative feedback on coagulation cascade since no anticoagulants present. No ability to inactivate factors V and VIII. Warfarin will decrease C and S before it the coagulation factors and leads to skin necrosis.

Autosomal Dominant
Recurrent DVT

12

Factor V Leiden:

Most commoninherited hypercoagulable state. Mutated FV resists degradation by protein C and S.

Autosomal Dominant
Recurrent DVT

13

Prothrombin 20210A

Point mutation causing increased prothrombin expression which promotes thrombus formation

Recurrent DVT

14

ATIII Deficiency

Decreased protective effect of heparin-like molecules produced by endothelium. Heparin like molecules usually activate ATIII and inactivates thrombin and coagulation factors.

Recurrent DVT
No rise in PTT with standard heparin dosing

15

Fibrinolysis

tPA converts plasminogen to plasmin. The plasmin cleaves fibrin and serum fibrinogen and destroyes coagulation factors and prevents aggregation. Alpha-2-antiplasmin inactivates plasmin. In this disorder we have activation of plasmin when there is no clot so there is no fibrin to cleave. Usually occurs in radical prostatectomy or cirrhosis of the liver (reduced production of Alpha-2-antiplasmin)

↑PT/PTT (coagulation factors destroyed)
↑bleeding time
↑fibrinogen split products but not D-dimers since no clot was really formed

Treat with aminocaproic acid which blocks plasminogen activation