Clotting/Platelet Disorders Flashcards
Petechiae usually occur as a side effect to what condition?
Thrombocytopenia
What is ITP (immune thrombocytopenia purpura)?
What does it occur as a result of?
What labs would you expect?
What is the treatment?
ITP is the creation of an Ab against platelet antigens like GP IIb/IIIa.
Expect low platelets since splenic macrophages eat the anitgen/Ab complexes.
Expect low plt, increase megakaryocyes, and normal PT/PTT since coagulation is not involved.
Treament is corticosteroids, IVIG to increase plt, and splenectomy to get rid of the Ab produced.
What is microangiopathic hemolytic anemia? What is the disease process?
Which two diseases are categorized this way?
MHA is a condition in which microthrombi are created in small vessels in the body. Platelets are consumed when microthrombi are made. RBCs are “sheared” as they pass the bumps, making schistocytes.
It involves TTP and HUS.
What is TTP (thrombotic thrombocytopenia purpura? What does it occur as a result of?
What labs would you expect?
What is the treatment?
TTP occurs as a result of decreased ADAMTS13 (keeps vWF low), so when it is not there platelet adhesion occurs
Expect low platelets with increased bleeding time, normal PT/PTT, schistocytes
Treatment involves plasmapharesis and corticosteroids
What is HUS (hemolytic uremic syndrome)? What does it occur as a result of?
What labs would you expect?
What is the treatment?
HUS occurs usually due to endothelial damage by infection (E.coli).
Expect low platelets with increased bleeding time, normal PT/PTT, schistocytes
Treatment involves plasmapharesis and corticosteroids
What is Bernard-Soulier Syndrome? How does it look on a blood smear?
It is a GP Ib deficiency (this is how platelets attach to vWF). It shows as thrombocytopenia with large platelets.
What is Glanzmann thromboasthenia?
GPIIb/IIIa defiency
What is the effect of aspirin on platelet aggregation?
It inhibits COX, which makes TXA2, so no platelet aggregation.
What factors are needed to activate the coagulation cascade?
Tissue thromboplastin for Factor VII, II, V, X, and fibrinogen (extrinsic)
Sub-endothelial collagen is needed Factor VIII, XII, XI, and IX and II, V, X, and fibrinogen (intrinsic)
Also, for both, need phospholipid surface for pH and calcium
What is Hemophilia A?
What labs would you expect?
A deficiency in Factor VIII.
Prolonged PTT with a normal PT
What is Hemophilia B (or Christmas disease)?
What labs would you expect?
Factor IX deficiency
Prolonged PTT, normal PT, normal platelets and bleeding time
What is the coagulation factor inhibition disease?
It is an acquired Ab against a coagulation factor resulting in impaired factor function. However, will be different than Hemophilias because in mixing studies, PTT will not be corrected.
What is von Willebrand Disease?
What labs would you expect?
What test do you expect?
What treatment?
Statistically low vWF
Prolonged PTT (decreased VWF causes decreased Factor VIII half-life)
An abnormal ristocetin test (a normal test should cause vWF to work it magic)
Desmopression as it increases vWF release from endothelial cells
What coagulation factors does Vitamin K deficiency affect?
Prevents activation of II, VII, IX, X, Protein C, and Protein S
What coagulation factors does Vitamin K deficiency affect?
Prevents activation of II, VII, IX, X, Protein C, and Protein S
