Hubbard: DVT and PE Flashcards
Which 3 factors of the anticoagulant pathway regulate clot formation by preventing excess thrombin production?
Protein C and S and antithrombin
What are the components of Virchow’s triad (3 factors that contribute to thrombosis)
- Venous stasis
- Endothelial damage
- Hypercoagulability
What is the most common thrombophilic disorder; leads to what?
- Factor V Leiden mutation –> activated protein C resistance
- Results in protein C being unable to inactivate factor V and VIII, which leads to unregulated prothrombin activation
Inherited Thrombotic Disorders
- Antithrombin III Deficiency
- Protein C and Protein S Deficiency
- Factor V Leiden Mutation
- Prothrombin 20210 Mutation
- Methylene Tetrahydrofolate Reductase Deficiency (Hyperhomocysteinemia)
- Factor XII Deficiency
- Dysfibrinogenemias
Acquired Thrombotic Disorders
- Protein C and Protein S Deficiency
- Dysfibrinogenemias
- Antiphospholipid Syndrome
Clinical clues of DVT/PE
- Homans sign: Pain in calf or popliteal area on
dorsiflexion of the foot - Moses sign (Bancroft signs): Pain with
compression of the calf against the tibia but not when
squeezing the calf itself (see
photo)
What is Lisker’s Sign?
Pain with percussion of the anteromedial tibia;
What is Lowenberg’s sign:
BP cuff applied to mid-calf and pain
elicited with inflation to 80 mmHg
What is Unilateral superficial venous distention/
veins of affected leg
distended in comparison to non-affected leg; not sensitive or
specific for DVT
Wells Criteria for DVT = (Risk of getting DVT)
- Active cancer = 1
- Paralysis/immobilization = 1
- Bedridden for >3 days or major surgery within 4 weeks = 1
- Entire leg swollen = 1
- Tenderness along deep vein = 1
- Calf swelling >3cm = 1
- Pitting edema (unilateral) = 1
- Collateral superficial vein = 1
- Alternative dx more likely than DVT = (-2)
Score and probability for Wells Criteria for DVT
High (3 or higher) = 75% risk
Moderate (1-2) = 20% risk
Low (0) = 3% risk
Wells Criteria for PE = (Risk of getting PE)
- Clinical evidence of DVT = 3
- Other dx less likely than PE = 3
- HR (>100) = 1.5
- Immobile >3 day or major surgery within 4 weeks = 1.5
- Previous DVT/PE = 1.5
- Hemptysis = 1
- Malignancy = 1
Score and probability for Wells Criteria for PE
High (6 or >) = 70% risk of PE
Moderate (2-6) = 20-30% risk
Low (<2) = 2-3% risk
20% of all patients with symptomatic DVT have underlying ______
malignancy
20% of all patients with symptomatic DVT have underlying malignancy. What are the MC?
- Lung
- Pancreas
- Colon/rectum
- Kidney
- Prostate
Trousseau’s Syndrome…
35% of Trousseau’s original
patient population eventually
died of
metastatic cancer
What cancer medications cause drug-induced hyper coagulability?
- Tamoxifen = proestrogenic effect increases risk of DVT/PE and stroke
- Bevacizumab = arterial and venous thromboses
- Thalidomide/lenlidomide = arterial and venous thromboses
What surgeries increase risk of DVT/PE?
Orthopedic, major vascular, neurosurgery, cancer
RF for getting DVT/PE during surgery
- Older age
- Previous venous thromboembolism
- Malignancy
- Medical illness
- Longer surgical, anesthesia, and
immobilization times
Other cases of hypercoagubility
- Sitting still for Long time
- Extended travel
- HF is a hyper coagulable state = greatest with R HF
What are Major risk factors for intracardiac thrombi
1. Reduced L ventricular function and a-fib
List 7 acquired prothrombic states which increase risk for thromboembolism.
- Antiphospholipid antibodies
- Malignancy
- Immobilization
- Surgery
- Pregnancy
- Estrogen
- Heparin-induced thrombocytopenia
What heriditary RF poses a 80x risk of first DVt/PE.
Homozygous Factor V Leiden or prothrombin gene mutation
Oral contraceptives/hyperhomocysteinemia and heterozygous Factor V
Leiden have a _____ effect on probability of developing DVT/PE
Synergistic (35x)
