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
What is the most common inherited bleeding disorder?
von Willebrand disease
How is von Willebrand disease diagnosed? how is it treated?
- diagnosed with a von Willebrand panel
- treat with DDAVP and products containing vWF
What is the first thing you should do if you see an unexplained abnormal coagulation test?
repeat the test! maybe not enough blood collected in the tube
A 24 year old female presents to clinic complaining of excessive menses. This is a typical presensation for which coagulopathy?
von Willebrand disease
What factor deficiency is seen in hemophilia A vs. hemophilia B?
- factor 8 (hemophilia A)
- factor 9 (hemophilia B)
