weber pre-lecture pt 1 Flashcards
pages 1-21
how are venous thrombi formed?
stasis blood leads to decreased clotting factor clearance
what is the composition of venous thrombi?
RBCs
fibrin
platelets
when do symptoms result?
flow is obstructed
vascular tissue wall is inflamed (after surgery/trauma)
thrombus ocurs and affects venous blood flow or emboli occur and enter pulmonary circulation
what is virchow’s triad?
hypercoagulable state
endothelial injury
circulatory stasis
what is a hypercoagulable state?
abnormalities of clotting components
example – pregnancy, cancer
what is endothelial injury?
abnormality of surfaces in contact with blood flow
example - surgery/trauma
what is circulatory stasis?
abnormalities in blood flow
example - long periods of immobility
what happens in the initiation stage?
injury exposes tissue factor bearing cell
X is converted to Xa/Va
Prothrombin is converted to Thrombin (in trace amounts) via Xa/Va
What happens in the amplification stage?
in the collagen-activated platelet, thrombin converts V, VIII/vWF, and XI to Va, VIIa + vWF, XI
what happens in the propagation stage?
in the collagen/thrombin-activated platelet,
prothrombin is converted into thrombin (in large amounts) via Xa/Va
fibrinogen is converted into fibrin via thrombin
what is postthrombotic syndrome?
long term complication of DVT caused by damage to venous valves
results in chronic venous obstruction, chronic pain/swelling, stasis ulcers, and development of infection
caused by venous hypertension
what are some risk factors of DVT?
> 40 yo
fam h/o of DVT
HF
immobilization greater than 10 days
pregnancy
malignancy
MI
obesity
orthopedic injury
oral contraceptives/estrogen
paralysis
postop state (within 3 months)
prior DVT
varicose veins
what are some non-pharmacologic txs of DVT?
bed rest with proper anticoag meds
elevation of feet
pain management
compression stocking
what are some non-pharm tx of PE?
oxygen
mechanical ventilation
what is UFH?
unfractionated heparin
what dosage form is UFH?
rapid, parenteral anticoagulation
IV
what is the monitoring parameters for UFH?
activated Partial Thromboplastic Time (aPTT)
goal –> 1.5 to 2.5 time control
how is UFH dosed?
by weight
what are AE of UFH?
bleeding
thrombocytopenia
what are the platelet count associated with HAT/HIT?
HAT –> mild decrease
HIT –> major decrease from baseline (over 50%) or under 100,000 mm3
in what type of thrombocytopenia, does all heparin need to be stopped?
in HIT
what are the associated characteristics of HAT?
non-immune mediated
occurs around 48-72 hours after admin
transient
do not d/c
what are the associated characteristics of HIT?
immune mediated
occurs between 1-2 weeks
can occur up to 9 days after stopping therapy
