im
difference between acute and chronic PE
acute = free floating
chronic = contiguous with vessel wall
what is done if PE is unprovoked
hypercoaguable work up
name 4 possible sources of emboli
thrombus
air
Amniotic fluid
Fat (from bone marrow after a fracture)
Foreign bodies
Parasites
Infection (septic emboli)
Tumor cells
what are high risk medications to cause PE
estrogen-containing contraception
post-menopausal estrogen replacement therapy
selective estrogen receptor modulators (like tamoxifen)
cancer therapies
name 1 LMWH and list 2 reasons why LMWH might be preferred over UFH
Enoxaparin (Lovenox), Dalteparin (Fragmin), Tinzaparin (Inohep)
Decreased risk of HIT
Can be used at home (bc it is IM injection)
at the main pulmonary artery bifurcation
why must IVC filters be removed at some point
they double risk of DVT in first 2 years
where are thrombi most and least likely to come from?
most likely- femoral veins/lower extremity
least likely- upper extremities or calves (below the knee)
purpose of anticoagulants?
PREVENT new clots, not dissolve current clots
what is heparin reversal?
Which type of heparin is fully reversed and what kind of heparin is partially reversed?
protamine sulfate
UFH fully reversed, LMWH partially reversed
name the 3 parts of virchow's triad and give an example of each one
venous stasis (ex. bed bound after surgery, polycythemia, pregnancy, travel)
vessel wall injury (ex. hypertension, damage from surgery, smoking)
hypercoaguability (ex inherited- factor V leiden or accquired- antiphospholipid syndrome)
when is IVC filter used for PE
Used when anticoagulation is contraindicated or if VTE recurs despite oral anticoagulants
reversal for dabigatran
Idarucizumab
when are thrombolytics/fibrinolytics indicated?
name 1 thrombolytics/fibrinolytic
name 1 absolute contraindication to thrombolytics/fibrinolyritics
high-risk PE, acute myocardial infarction, and acute ischemic stroke
Alteplase (tPA) and Tenecteplase
previous intracranial hemorrhage, active internal bleeding, recent ischemic stroke or head trauma within the past 3 months
biggest risk factor for PE?
a previous PE
what is the most accurate diagnostic method for PE?
why is it less preferred than the gold standard?
Pulmonary Angiography
It is invasive
what is primary reversal of warfarin, and what is used if primary reversal agent(s) cannot be used?
Why is the alternative less preferred (aka what side effects can happen from the alternative)?
4-Factor PCC (Kcentra) + IV vitamin K = primary
Plasma / FFP + vitamin K
Plasma / FFP + vitamin K is less preferred because it is slower, larger volume is required, and Risk of fluid overload / transfusion reactions
when do you need to initiate dabigatran in relation to parental therapy
parental therapy = 5-7 days
Initiate dabigatran < 2 hours prior to time of next scheduled dose of parental anticoagulation
name all medications that need to be monitored while patient is taking by either PT/INR or aPTT/PTT
warfarin (PT/INR)
UFH (aPTT/PTT)
gold standard for diagnosing a PE and what is used if the gold standard cannot be used
CTA is gold standard, V/Q scan used when CTA is contraindicated
name 3 things that can indicate PE on CXR
Palla's sign (enlarged right descending pulmonary artery)
Westermark’s sign (hyperlucency)
Hampton’s hump (wedge-shaped opacity representing pulmonary infarct)
why does warfarin require bridging therapy?
Because Protein C and S are depleted rapidly, initiating warfarin creates a temporary pro-thrombotic state
what is general MOA of HIT
Body forms antibodies to heparin, antibodies cause platelet sequestration and paradoxical thrombosis
what is parental therapy that is NOT UFH or LMWH?
what is its MOA?
name reversal agent
Pentasaccharides (Fondaparinux)
indirect inhibition of factor Xa via antithrombin III
no reversal agent