Hemostasis Flashcards
Acute ITP
arises in children after a viral infection or immunization
Self limited
Bernard-Soulier syndrome is
Genetic GP-1b deficiency impairing platelet adhesion
Blood smear in Bernard-Soulier shows
Enlarged platelets
Children with E coli think
HUS
Chronic ITP
arises in adults, usually women of childbearing age
May cause short-lived thrombocytopenia in offsprings
Clinical features of disorder of primary hemostasis
- Mucosal and skin bleeding
- Epistaxis
- Hemoptysis
- GI beeding
- Intracranial bleedin occurs with severe thrombocytopenia
Clinical findings in HUS and TTP
Microangiopathic hemolytic anemia
Renal insufficiency (HUS)
CNS abnormalities (TTP)
DIC is secondary to
- Obsteric complications: Tissue thromboplastin in Amniotic fluid
- Sepsis
- Adenocarcinoma
- Acute promyelocytic leukemia
- Rattlesnake bite
Ecchymoses is
>3 mm of skin bleeding
Glanzmann thrombasthenia is due to
A genetic GP-2b/3a deficiency impairing platelet aggregation
Hemarthrosis
Deep tissue bleeding into muscles and joints
Hemophilia A is due to
X-linked ressive deficiency in Factor 8
Hemophilia B a.k.a.
Christmas disease
Hemophilia B is a deficiency of
Factor 9
How do you test vWF deficiency
Ristocetin test that induces platelet aggregation by causing vWF to bind platelet GP-1b
How do you treat vWF deficiency
Desmopressin
Immune thrombocytopenia purpura (ITP) is
Autoimmune production of IgG against GP-2b/3a
Lab finding in Hemophilia A
Increase PTT
Decrease F8
Normal platelet count and BT
Lab findings in DIC
- Decrease platelet count
- Increase PT and PTT
- Decrease fibrinogen
- Microangiopathic hemolytic anemia
- Elevated D-dimer
Lab findings in HUS and TTP
- Thrombocytopenia with increase BT
- Normal PT/PTT
- Anemia with schistocytes
- Increase megakaryocytes on BM biopsy
Lab findings in ITP
- Decrease platelet count (Destroyed by speen)
- Norman PT/PTT
- Increase megakaryocytes on BM biopsy
Lab findings in vWF deficiency
Increase BT
Increas PTT
Microangiopathic Hemolytic Anemia (MAHA) is
A pathologic formation of platelet microthrombi in small vessles
RBCs are sheared when they cross microthrombi resulting in hemolytic anemia with schistocytes
Petechiae is
1-2 mm of skin bleeding
Signs of thryombocytopenia and not usually seen with qualitative disorders
Platelets bind vWF using
GP-1b
Purpura is
> 1 cm skin bleeding
Thrombocytopenic purpura (TTP) is due to
Decreased ADAMTS13 an enzyme that cleaves vWF for degradation
Von Willebrand disease is
AD Genetic vWF deficiency
Causes quantitative and qualitative defects
What are thormbi characterized by
Line of Zahn: alternating layers of platelets/fibrin and RBC
What inactivates plasmin
α2-antiplasmin
What promotes exposure of GP-2b/3a
ADP released from platelet dense granules
