Hemostasis Defects Flashcards
What is the INR? What does an INR of 2 mean?
International Normalized Ratio. It is a measure of the PT. 1 is normal so 2 is twice normal.
A deficiency in which factors will cause a prolonged PT? What else could potentially cause a prolonged PT?
- 2, 7, 5, 10
- Vitamin K
- liver disease
A deficiency in which factors will cause a prolonged PTT?
Anything except VII (especially VIII, IX, XI, XII).
What prolongs the thrombin Time (TT)?
heparin contamination, fibrinogen deficiency, increased fibrinolysis, or abnormal fibrinogen
T or F factor deficiencies prolong the bleeding time?
false.
What prolongs the bleeding time?
- severely decreased platelet count
- vWF disease
- other abnormalities in platelet fxn.
What is the PFA-100?
in vitro bleeding time. Stands for the Platelet Function Analyzer
Hemophilia A and B have an abnormal _______ and a normal _____ and _____
PTT (elevated)
PT
BT
Think about what factors it affects
Hemophilia A affects factor ____ while hemophilia B affects factor _____
VIII (hemophilia AAAAyyyyeight)
IX
how are mild hemophiliacs (>10% factor activity) diagnosed?
usually after a bad traumatic injury or after a bad result from surgery
FYI:
carrier females- 30-100% activity
moderate hemo - 5-8% activity
Severe- less than 1% activity
Hematomas can cause what?
muscle damage. They can also cause calcified pseudotumors and atrophy.
What are you worried about in a knee joint bleed?
arthritis.
start treatment with adding factor as soon as you start feeling tingling.
Hemophilia C is also called what?
factor XI deficiency. Usually presents with post-operative hemorrhage (especially prostate, uterus, bladder surgery) since they probably won’t have bleeding disorders.
What is prolonged in a factor VII deficiency?
only the PT.
what are the functions of vWF?
From this can you guess what will be prolonged in vWF disease?
- adhere platelets to exposed collagen
- carry factor VIII
Prolonged Bleeding Time (BT) and PTT
What is an important finding in those with vWF disease?
bleed after surgery
A patient with acquired factor VIII inhibitor will have a prolonged _____. Why will this not correct after mixing with normal plasma and incubating for 2 hours?
PTT
The patient is making antibodies against factor VIII (autoimmune disease) so the new factor VIII is destroyed and PTT remains prolonged.
Causes of prolonged PTT?
- heparin
- Hemophilia (congenital or acquired)
- Factor XI, XII deficiency
- vWF disease
- Lupus anticoagulant
Causes of prolonged PT and PTT (PT longer than PTT)?
- Liver disease
- Vitamin K deficiency
- warfarin or rat poison
Causes of prolonged PT and PTT (PTT longer than PT)?
DIC
In patients with Liver disease it is important to make sure there is not a component of ______ making it worse.
Vitamin K deficiency
What are the most important laboratory findings in DIC?
- fibrinogen level has decreased markedly
- platelet count is low
Also will see increased D-dimer and fibrin split products
What is the best way to treat DIC?
Have to treat the underlying disorder (i.e. APL)
What causes Antiphospholipid Antibody syndrome and how does it work?
It is caused by the Lupus Anticoagulant, an antibody which binds to phospholipid. The result of this can be confusing because the patient presents with a prolonged PTT but an increased risk of thrombosis.
What test results will allow you to diagnose the lupus anticoagulant?
Do PTT. Add plasma with factors. repeat PTT. If the results do not improve at all, its gotta be lupus anticoag.
FYI:
This syndrome can be caused by much more than lupus disease. thats just the name.
What are the four most common familial congenital conditions which cause a hyoercoagulable syndrome?
deficiencies in antithrombin, protein C, protein S or resistance to protein C (also called Factor V Leiden)
