Freeman: Coag Flashcards
(37 cards)
What does it mean if you have factor V leiden? What happens to patients with Factor V Leiden?
you have a mutation in factor 5, so you can’t bind protein C and cannot degrade factors 5a and 8a, so you get a state of hypercoagulation; usually nothing happens to these patients; however, if they have other predisposing symptoms, then they will be at increased risk of hypercoagulation (clotting)
What are these?
Obesity
Sedentary life-style
Travel
BCP’s
Pregnancy
Surgery
*elective, particularly
ortho
Smoking
Prior DVT
modifiable risks for hypercoagulation
What are these?
Factor V Leiden
Prothrombin Gene Mutation
Malignancy
Surgery
*emergent
Chronic Illness
Lupus Anticoagulant
unmodifiable risks for hypercoagulation
How long must patients be kept on heparin?
7-10 days, even if you start the heparin with coumadin
What are the Vit K dependent coagulation factors?
2, 7, 9, 10
protein C and protein S
Why must a patient who is on both heparin and coumadin be kept on heparin for 7-10 days?
because coumadin takes a while to take effect, because it works on the Vit K dependent coag factors (2, 7, 9, 10, protein C and S) - these factors have long half-lives, so if you give coumadin, some coag factors will still be floating around for awhile
Patients require (blank) days of full heparinization regardless of
when adequate coumadinization
occurs.
7-10
Is lupus anticoagulant an anticoagulant?
no! it’s actually a procoagulant in vivo
What is this?
Modest, transient decrease in platelets 2/2 heparin-induced platelet agglutination.
Self-limited; plt counts can return to normal while heparin is continued.
Heparin induced thrombocytopenia Type I
What is this?
A drug-induced, immune-mediated response 2/2 abs directed against heparin-plt factor 4 complex that results in a 50% or greater drop in platelet counts.
Severe thrombocytopenia w/bleeding is rare!
HIT Type II
What is the major problem with heparin induced thrombocytopenia?
the creation of a prothrombotic state, which can occur even after heparin has been discontinued
**seen most commonly in major surgery
What is the paradox with HIT?
can cause thrombocytopenia and thrombosis
**thrombosis w/ declining platelets seen in 50% of pts w/ recent hospitalization
This should be considered in all recently hospitalized patients returning w/ acute thrombosis w/i 1-2 weeks of their hospital stay
HIT
When is HIT most likely to occur?
in surgical patients, as opposed to medical patients
Widespread activation of the clotting cascade causing a consumption of clotting factors and platelets w/resultant bleeding
DIC
Thrombin formation causes microvascular compromise and results in tissue ischemia with resultant organ damage
DIC
Things that can trigger DIC
gram - septicemia (gram + too) damaged cerebral tissue damaged cerebral tissue placental tissue from obstetric catastrophies snake venoms acute hemolytic transfusion rxns massive tissue injury
3 things that can activate the coagulation cascade
endotoxin
IL-I
TNF
**these lead to the release of tissue factor
What happens to the following in DIC?
PT/PTT
platelets
fibrinogen
D-dimer
increased PT/PTT
decreased platelets
decreased fibrinogen
increased D-dimer
How do you treat DIC?
treat the underlying condition
ex: if secondary to bacterial infection, give antibiotics
5 things that can cause major bleeding
trauma infections drugs disorders of coagulation systems disorders of organ systems
3 cases in which you might get a prolonged PT
malnutrition
liver disease (decreased synth of Vit K)
coumadin
3 cases in which you might get a prolonged PTT?
lupus anticoagulant/acquired factor inhibitors
factor 8/9 deficiency or inhibitor
heparin
Type 1 von Willebrand Disease is a (blank) deficiency
quantitative
