Exam 4 - Venous Thromboembolism Flashcards
What is the recurrence rate of venous thromboembolisms?
1/3 of persons who survive the first occurrence of VTE develop another VTE within 10 years
What is Virchow’s Traid?
VTE Pathogenesis
Stasis (alterations in blood flow)
Hypercoagulability
Vascular endothelial injury
What is considered a major risk factor for recurrent VTE?
Previous thrombotic event
What are the most common chronic conditions that have an acquired risk factor for VTE?
Malignancy
Antiphospholipid antibody syndrome
Myeloproliferative disorders
What are the most common transient states that have an acquired risk factor for VTE?
Surgery
Trauma
Immobilization
Presence of a central venous catheter
What are the most common female specific factors that have an acquired risk factor for VTE?
Pregnancy
Hormonal contraceptives
What are the most common inherited risk factors for VTE?
FactorV Leiden mutation
Prothrombin gene mutation
What are the classic symptoms seen with DVT?
Often asymptomatic Swelling Pain Warmth Erythema Palpable cord
What is the most useful finding on exam for a DVT?
A large calf diameter
What is Homan’s sign?
Positive if there is pain in the calf on abrupt dorsiflexion of the patient’s foot while the knee is extended
*Not commonly used (low sensitivity and specificity)
What is the Wells criteria?
Scoring system to help confirm or rule out DVT before ordering any diagnostic tests
What are some of the features included on the Wells criteria?
Paralysis or recent orthopedic casting Bedridden Major surgery Localized tenderness Swelling of entire leg Calf swelling Pitting edema Active cancer
What feature on the Wells criteria has a score of -2?
Alternative diagnosis more likely than DVT
What does a Wells score of >3 indicate?
High probability of DVT
What does a Wells score of 1-3 indicate?
Moderate probability of DVT
What does a Wells score of 0 or less indicate?
Low probability of DVT
After calculating the pretest probability, what should be done for patients with low or moderate probability for DVT?
D-dimer should be ordered
What what levels in a serum D-dimer detectable?
Greater than 500 ng/mL in virtually all patients with VTE
Does the D-dimer test have high sensitivity or specificity? What does that mean?
The test is sensitive, but not specific
Only useful when negative and low clinical suspicion
If a patient has a low or moderate pretest probability for DVT and a negative D-dimer what should be done?
Nothing, no further work up needed
After calculating the pretest probability, what should be done for patients with high probability for DVT?
D-dimer is inappropriate, further workup required
Compression ultrasound
(CTV and MRV rarely used)
What is the indicated treatment DVTs?
Anticoagulants
What is the purpose of anticoagulants in the treatment of DVT?
Prevent further clot propagation
Prevent pulmonary embolism
Decrease risk of reoccurrence
Decrease risk of complications
What is not the purpose of treatment of DVT through anticoagulation?
To dissolve the clot
How long is initial anticoagulation given for DVT?
10 days
How long is long term anticoagulation given for DVT?
Minimum of 3 months
Along with anticoagulants, what else is used in the treatment of DVT?
Early ambulation
Compression stockings
What can cause upper extremity DVT?
Spontaneous
Secondary- more common (catheter placement)