Coagulation Bleeding Flashcards
What is an abnormal PT/aPTT finding?
if times are prolonged
What are the 2 main coagulation tests?
- PT and aPTT
PT pathway is also called what?
extrinsic pathway
aPTT pathway is also called what?
intrinsic pathway
What does activated factor X do?
converts prothrombin (factor II) into thrombin (factor IIa)
What 4 factors make up the common pathway?
Factors I, II, V, X
What does thrombin (IIa) do?
converts fibrinogen (factor I) into fibrin
What are the 2 factors in the extrinsic pathway?
- VII and X
- 7, 10
What are the 5 factors in the intrinsic pathway?
- XII, XI, IX, VIII, X
- 12, 11, 9, 8, 10
Deficiency in the vWF results in what change to the PT/aPTT?
No change
trick question
If you have a severe deficiency in vWF what other factor deficiency will you have? This will prolong which coagulation test?
- VIII
- will prolong aPTT
What are the only 2 factors NOT made in the liver?
- VIII, vWF
What are the 3 natural anticoagulants?
- antithrombin
- Protein C
- Protein S
- Protein C degrades Va/VIIIa
- Protein S cofactor of protein C
What enzyme is necessary to convert plasminogen to plasmin to break down a fibrin clot?
- tPA
Vitamin K is required for synthesis of what factors and proteins?
- II, VII, IX, X (2, 7, 9, 10)
- protein C and S
Action of vitamin K is blocked by this medication
warfarin (coumadin)
What time do you expect to be prolonged with vitamin K deficiency?
PT only
why PT? because Factor VII has the shortest half-life
vitamin K deficiency usually results from what?
malnutrition and antibiotics
What coag findings do you expect to see in liver disease?
- decrease in most clotting factors results in elevation in PT/INR
- decrease in protein C, protein S
- aPTT elevated when severe
- creates a state of both bleeding and thrombotic susceptibility
What are the lab abnormalities that will tell you a patient is in DIC? (5 findings)
- elevated aPTT
- elevated PT
- decreased fibrinogen
- elevated D-Dimer
- low platelets + schistocytes
A patient presents with recurrent hemarthroses, soft tissue hematomas. Labs demonstrate a prolonged aPTT but normal PT. What is the diagnosis? What is the treatment?
- hemophilia
- factor replacement via IV infusion
How is an acquired factor inhibitor diagnosed?
PT/aPTT mixing studies
You suspect a patient has acquired factor inhibitor. What results on a PT/aPTT mixing study indicates a factor deficiency vs. a antibody present?
- factor deficiency = mix will correct abnormal time
- antibody present = mix will NOT correct abnormal time
How is an acquired factor inhibitor condition treated?
immunosuppressants
