Week 3: coagulation disorders Flashcards
(40 cards)
What is the molecular dysfunction in Hemophilia A?
Mode of inheritance?
Appearance of PT/PTT test?
There is little to no Factor 8.
X Recessive
Prolonged PTT, normal PT, can correct with normal plasma addition
What is the presentation of Hemophilia A?
Deep bleeding into joints
Hematomas
Hemarthrosis
Post-circumcision bleeding
How do you treat Hemophilia A?
EDUCATION
- Desmopressin - increases vWF (which stabilizes and carries factor 8)Only works in patients that can produce SOME factor 8.
- Aminocaproic Acid - Inhibits fibrinolysis, allowing the person to clot.
- Physical Therapy
What does the platelet count look like in Hemophilia A?
Normal
What does the platelet count look like in ALL the hemophilias?
Normal. Coag disease. Not platelets.
What is the most common inherited bleeding disorder?
Von Willebrand Disease
vWF Disease Mode of Inheritance?
AD
What 2 jobs does vWF do and where is it synthesized/stored?
Function:
1. Platelet binding to subendothelial collagen
- Carries Factor VIII (8)
Synthesized in platelets, MKs, and endothelium.
What do the PT/PTT tests look like in vWF disease?
Prolonged PTT because lack of vWF causes lack of Factor 8.
How does a patient with vWF present?
Bruising easily
MUCOSAL BLEEDING- nosebleeds (epistaxis) characteristic
Menorrhagia
How do you treat vWF Disease?
Desmopressin - increases endothelial release of vWF
Aminocaproic Acid - inhibits Fibrinolysis
What tests do you run to confirm you have vWF?
RISTOCETIN TEST - impaired aggregation.
Everything clots with Ristocetin. Except vWF Disease.
How many factors are usually impaired in a hereditary coagulation disorder? What about acquired?
Hereditary: ONE
Acquired: Many
- DIC
- Drug
- Liver Disease
What is thrombophilia?
An increased tendency to clot
Name the 4 heritable Thrombophilias we talked about.
Factov V Leiden
Antithrombin 3 deficiency
Protein C/S deficiency
Prothrombon gene mutation G20210A
What is the most common inherited Thrombophilia?
Factor V Leiden mutation
What is the Pathology of Factor V Leiden mutation?
Factor V has an Arg506Glu mutation that makes it resistant to degradation by Protein C.
How do you test for Factor V Leiden mutations?
Add Protein C and observe PT/PTT. If they are both NORMAL, then Factor V is resistant.
(+) test for Factor V Leiden mutation
Then PCR Screen for the mutation
When do you treat Factor V Leiden mutation?
When a thrombus occurs, or when there is significant risk of one. (long flights)
If there are no thrombi present, and no history of them, DONT TREAT.
How do you test for an Antithrombin III deficiency?
Inject Heparin and look at the PTT. There should be no change in the PTT because Heparin has nothing to bind to.
How do you treat Antithrombin III deficiency?
Antithrombin replacement
How does deficiency in Proteins C and S present? (Think Warfarin)
Skin necrosis, thrombosis
Depletion of Proteins C and S remove inhibition from the coagulation cascade, letting it go crazy.
What happens if you have a Prothrombin Gene Mutation G20120A?
There is sustained generation of thrombin in the blood plasma.
Increased thrombosis
Decreased Fibrinolysis
A patient presents with spontaneous skin purport, mucosal bleeding, and excessive bleeding when wounded. How do you know if this is a Thrombocytopenia or vWF disease?
RISTOCETIN TEST
Won’t clot if it’s vWF
