VTE lecture Flashcards
Venous thromboembolism (VTE) results from clot formation within the venous circulation and is manifested as what 2 things?
Deep vein thrombosis (DVT) and/or pulmonary embolism (PE)
1) What sex does VTE occur more often in?
2) What age group?
1) Women
2) 75 y/o+
What is Virchow’s triad?
1) Blood stasis
2) Vascular injury
3) Hypercoagulability
Virchow’s triad: Give 2 reasons for Blood stasis
Surgery or immobility
Virchow’s triad: Give 3 reasons for vascular injury
1) Major orthopedic surgery (e.g., knee or hip replacement)
2) Trauma (especially fractures of the pelvis, hip, or leg)
3) Indwelling venous catheters
Virchow’s triad: Give some reasons for hypercoagulability
1) Malignancy
2) Pregnancy or up to 6 weeks postpartum
3) Cancer therapy
4) Heparin-induced thrombocytopenia
5) Meds
Virchow’s triad: Hypercoagulability:
1) What 2 drugs are SERMS? (selective estrogen receptor modulators)
Tamoxifen and raloxifene
List 6 things that interfere with thrombin activation
1) Antithrombin
2) Heparin
3) Thrombomodulin
4) Protein C
5) Protein S
6) Tissue factor pathway inhibitor
List 3 drugs that interfere with thrombin (IIa)
Heparin, LMWH, and dabigatran
List 4 drugs that interfere with factor Xa of the common pathway
Heparin, LMWH, apixaban and rivaroxaban
Intact endothelium adjacent to the damaged tissue actively produce several antithrombotic substances:
_______________ modulates thrombin activity by converting protein C to its active form (aPC)
Thrombomodulin
Intact endothelium adjacent to the damaged tissue actively produce several antithrombotic substances:
aPC + cofactor protein S inactivates what 2 factors?
Va (5a)
& VIIIa (8a)
Antithrombin is a circulating protein that inhibits thrombin and what?
factor Xa
Heparan sulfate, a heparin-like compound secreted by endothelial cells, exponentially accelerates _______________ activity
antithrombin
Inactive plasminogen is converted by ______________________ to active plasmin, an enzyme that degrades fibrin mesh into soluble end products collectively known as fibrin degradation products including ___________ which is a marker of thrombosis used when diagnosing VTE
tissue plasminogen activator (tPA); D-dimer
Inherited hypercoagulability disorders:
1) aPC resistance most often results from a __________________ that renders factor V resistant to degradation by aPC.
2) What mutation increases circulating prothrombin?
1) gene mutation (factor V Leiden)
2) Prothrombin G20210A
List 3 ways to acquire hypercoagulability disorders
1) Malignancies
2) Antiphospholipid antibodies
3) Estrogen use
A negative D-dimer, for most assays defined as ____________________ (mcg/L), can be useful in ruling out the diagnosis of VTE
<500 ng/mL
1) Who do you want to initiate prevention of VTEs?
2) List 3 nonpharmacologic preventions
1) high-risk surgical and medical populations
2) -Ambulation
-Compression stockings and intermittent pneumatic compression (IPC)
-Inferior vena cava (IVC) filters
_________________________ can provide short-term protection against PE in very high-risk patients by blocking embolization of thrombus formed below the filter
Inferior vena cava (IVC) filters
VTE prevention:
1) What score do you use in medical patients? What is high risk
2) What about in surgical patients? What is high risk?
1) Padua Prediction Score
High risk score ≥4 points
2) Caprini Score
High (≥5 points) (give anticoag.)
Most clinical trials support the use of antithrombotic prophylaxis for __________ to ________ days following total knee or hip replacement surgery
15 to 42 days
(abt 2 to 6 weeks; closer to 2 for knee and 6 for hip)
The appropriate initial duration of anticoagulation therapy to effectively treat an acute first episode of VTE for all patients is how long?
3 months
Direct oral anticoagulants (DOAC):
1) List 2
2) Which is preferred (per BEER’s list)? Which should you avoid and which should you caution?
1) Apixaban (Eliquis) and rivaroxaban (Xarelto)
2) Apixaban; Avoid rivaroxaban, caution dabigatran
