Venous Thromboembolism Flashcards
Where does a DVT usually form?
in the lower extremities
DVT
deep vein thrombosis
PE
Pulmonary embolism
What are the 3 factors (known as Virchow's Triad) that play a role in clot formation? These factors are abnormalities in. . . 1. 2. 3.
- blood flow
- clotting components
- surfaces in contact with blood
Signs & symptoms of DVT:
leg pain & swelling
temperature difference b/w the 2 extremities
palpable cord along the vein in the affected extremity
Homan’s sign
What is Homan’s sign?
dorsiflexion of the foot leads to pain behind the knee of the affected extremity (if the patient is laying down, and you pull back on their toes, it is extremely painful for them)
What is a clot that forms in the venous circulation and presents as either a DVT or PE
venous thromboembolism
Signs & symptoms of PE:
cough chest pain/tightness shortness of breath hemoptysis dizziness/light-headedness tachypnea tachycardia diaphoresis distended neck veins cyanosis
What is the most commonly used pretest probability scoring system?
Wells score
FYI
A _________ ________ is used most commonly to diagnose a DVT?
Doppler ultrasound
- -non-invasive
- -can measure the rate & direction of blood flow to identify clots in proximal veins (cannot detect small clots in distal veins)
What is a byproduct of thrombin generation and may be elevated in patients with a DVT and PE?
D-Dimer (a blood test to determine if a pt has a clot)
What is the gold standard for detecting a DVT?
Venography
- -not used as often because it is more invasive and some patients experience anaphylaxis
- -requires use of a radiopaque dye
____________ _________ scan images of the lungs to help detect an embolus.
Computerized tomography (CT)
The risk of DVT or PE doubles with each decade after _____ years of age.
50
What are the risk factors for DVT?
age (doubles for each decade past 50 yo) prior VTE inherited or acquired thrombophilia major medical illness or surgery paralysis/immobility obesity varicose veins trauma (especially to pelvis, hips, or legs) indwelling venous catheters (rougher surface) pregnancy/postpartum cancer/cancer therapy estrogen-containing products (birth control, hormone-replacement)
__________ increases the risk of VTE and is compounded in patients who _______ and are taking an estrogen-containing drug.
Smoking, smoke
What are some coagulaopathies that can cause abnormalities in coagulation?
Factor V Leiden (most common) protein C or S deficiency antithrombin deficiency antiphospholipid antibodies hyperhomocysteinemia
Factor V Leiden is also called. . .
activated protein C resistance
What do we do if no risk factor can be identified for a pt developing a VTE?
coagulation studies
Since a pt isn’t likely to use medical terminology, what words would a patient use to describe symptoms of a DVT?
my leg is swelling (when did this start?)
one leg feels hotter or colder than the other (have you noticed any kind of temperature differences?)
(any other conditions?)
(questions to ask the patient)
A patient presents to the ER with sudden onset CP (chest pain) and SOB (shortness of breath). What tests would be used to rule in or out a PE?
CT
look for coagulopathies
explain the pathophysiology of a VTE to a pt without using medical terminology. this pt has Factor V Leiden and is about to start warfarin.
You’re blood is too thick and this medicine will thin it and decrease your risk of clotting
Which parenteral anticoagulant is the easiest to reverse (has an antidote)?
heparin
Once we know a patient has a VTE, what do we do?
start drug therapy immediately
to prevent further growth of a blood clot
What is the purpose of starting drug therapy immediately after diagnosing a VTE?
to prevent future growth of the blood clot
[SATA] What is the bolus dose (LD) of UFH? A. 18 units/kg/hr B. 80 units/kg C. 5000 units/hour D. 1000 units/hour
B or C (if we don’t know pt’s wt)
SATA] What is the continuous infusion dose (MD) of UFH? A. 18 units/kg/hr B. 80 units/kg C. 5000 units/hour D. 1000 units/hour
A or D (if we don’t know pts wt)
aPTT
activated partial thromboplastin time
What is the lab test that is typically used to identify the appropriate level of anticoagulation?
aPTT
aka: PTT
What is the most common adverse effect of heparin?
BLEEDING