Hemostasis - Unit 3 Flashcards
What is hemostasis?
Blood stagnation/the process of clot formation.
In simple terms, how does this work?
Tissue injury —> Platelet Plug —> Biochemistry –> Clot
When an injury occurs, what factor affects the common pathway?
Factor 10
Factor 10 (X) - what happens after this?
Prothrombin –> Thrombin –> Fibrinogen –> Fibrin –> Clot
Why does the coagulation process matter?
Because lots of drugs we give affect this!
Bleeding & Clotting Disorders - Platelet Issue or Factor Issue - T/F?
True!
What are the platelets? How do they act in a bleed?
First responders, unstable platelet plug, they trigger clot formation, and repair microvascular injuries.
Is a platelet plug very stable?
Not at all - it tends to go away within an hour. It’s easy to break away - it does this because it signals the body to create a clot.
Thrombocytopenia - def
Low Platelet
Thrombocytosis/thrombocythemia - def
high platelet count - not general symptomatic.
Von Willebrand Factor (vWF) deficiency - what is it?
A platelet or factor problem.
What is Von Willebrand disease?
Typically, it gets platelets to adhere to site of injury. It activate them.
In this disease, inadequate/ineffective vWF reduces platelet adhesion, activation and aggregation.
What are some signs and symptoms of platelet problems?
Nosebleeds (epistaxis), Bleeding gums, Heavy menstrual bleeding, bruising, melena (black/bloody stool), symptoms of anemia.
What are some treatments for Thrombocytopenia/VWD?
SAFETY FIRST!!!
Prevent blood loss. We might need to do a transufsion, DDAVP, immunosuppresant drugs, plasmapheresis.
What does DDAVP (Desmopressin) do for blood?
At what level do we usually transfuse? Are we careful with it?
If you have any VWF, it releases it!
How do we treat thrombocytosis?
Platelet aggregation inhibitors - usually there isn’t even a need for treatment, though.
Factor issues - are they more or less severe than platelet issues?
More severe!
What’s Factor V Leiden?
Doesn’t degrade - so we have a prolonged clot.
The liver - what does it do for blood?
Filters/produces many clotting factors. It also clears TPA and urokinase
What are some signs and symptoms of factor problems?
Platelet-type bleeding plus excessive bleeding from minor injuries, muscle and joint bleeding, prolonged hemorrhage, prolonged bleeding
How do we treat factor issues?
Factor concentrates - but these are expensive.
Only one good concentrate exists, but it works for factor 8 only.
Desmopressin, Platelet transfusion, plasma transfusion (FFP), Vitamin K
What should a normal platelet count be?
150,000-420,000
What do the PT, INR & PTT do?
Measure time from platelet activation to clot formation/how long it takes body to recognize need for formation.
PTT - which drug? Normal levels?
Heparin - normally 25-35 seconds, but should be 1.5-2.5 times faster when on heparin.
PT/INR - Drug? Normal Levels?
Coumadin. Should normally be 11-14 seconds (PT) and .8-1.2 for INR. With coumadin, INR should be about 2.5-3.5
Do we usually start Coumadin before stopping heparin?
Yes!
What does antithrombin do?
It prevents thrombin doing its work.
What does fibrinolysis do?
Deals with plasminogen - binds to fibrinogen and the clot. It regulates.
What is HIT?
Heparin Induced Thrombocytopenia - starts about 5-14 days after receiving heparin. It reduces the platelet count because antibodies attack the platelets. We need to stop heparin and give another anti-coagulant, because there will be both clotting and bleeding with this condition.
What is DIC?
It is serious - it’s called Disseminated Intravascular Coagulation - it’s overactive clotting. Also causes depletion of platelets and clotting factors. Give clotting factors and transfuse.
