Diagnosing DVT/PE Flashcards
Virchow’s triad
stasis
vessel wall injury
hypercoagulability
Major risk factors for venous thrombosis
major surgery
late pregnancy
lower limb fracture
malignancy
reduced mobility
previous DVT
Minor risk factors for venous thrombosis
congenital heart disease
cardiac failure
hypertension
central venous catheter
oral contraceptive/HRT
long distance sedentary travel
thrombotic disorders
obesity, COPD
IVDU
Lower limb DVT differential diagnoses
cellulitis
ruptured popliteal cyst
muscle tear/haematoma
fracture
lymphoedema
hypoproteinaemia
Lower limb DVT complications
acute pain and immobility
chronic leg swelling/pigmentation
venous insufficiency and ulceration
increased risk of future DVT
risk of PE
What does D-dimer measure?
degradation products of cross-linked fibrin
released when the fibrinolytic system attacks the fibrin matrix of fresh venous thromboemboli
What diseases can give a false positive D-dimer?
cancer
peripheral vascular disease
inflammatory/infective conditions
postoperatively
increasing age
Wells score components (DVT)
active cancer = 1
paralysis or recent lower limb immobilisation = 1
bedridden for >3 days or major surgery within 4 weeks = 1
localised tenderness along the distribution of the deep venous system = 1
entire leg swollen = 1
calf swelling >3cm of other side (10cm below tibial tuberosity) = 1
pitting oedema = 1
dilated collateral superficial veins = 1
pregnancy = 1
alternative diagnosis as likely or more likely than DVT = -2
Interpretation of DVT Wells score
0 = low probability DVT
1/2 = moderate probability DVT
3 = high probability DVT
How does a pulmonary embolism occur?
venous thrombus breaks off
moves through venous circulation
right atrium/ventricle
pulmonary arteries
gets stuck
pulmonary infarction
PE signs/symptoms
breathlessness
pleuritic chest pain
haemoptysis
arrhythmias
sudden death
