Venous thrombo-emboli (DVT and PE) Flashcards
Where is the most common location of a DVT?
Below/around calf (less concerning)
Anterior and posterior tibial veins (minor)
Where is a more life-threatening location of a DVT?
Above calf (in thigh) eg in superficial femoral vein (major veins)
Occlusion here may impeded distal flow
A PE occurs when a DVT embolises and lodges in the ______ _____ circulation
pulmonary artery
What does Virchow’s triad consist of?
Hypercoagulability
Endothelial injury
Venous stasis
What affects hypercoagulability of blood, increasing risk of DVT/PE?
Pregnancy
Combined oral contraceptive pill
Obesity
Antiphospholipid syndrome
Sepsis
DIC
Malignancy
APS is an _____ disorder characterised by presence of ______ antibodies in the blood, with a tendency to develop blood clots. The antibodies target phospholipids and interfere with normal functioning and increase risk of abnormal blood clotting in veins and arteries.
autoimmune
antiphospholipid
APS commonly causes _____ complications
pregnancy
Increased risk of placental thrombosis, impairing foetal development
What are signs other than thrombi of APS?
Livedo reticularis (mottled skin discolouration)
Cognitive dysfunction, headaches, seizures, transverse myelitis
Heart valve abnormalities
Cardiomyopathy
Renal artery thrombosis and nephropathy
What is transverse myelitis?
Neurological disorder characterised by inflammation of spinal cord causing weakness (below level of inflammation), sensory disturbances, pain, fatigue and bowel and bladder dysfunction.
Typically affects both sides of spinal cord
Unknown cause, thought to be autoimmune reaction idiopathically or following infection, MS or systemic autoimmune diseases.
What affects endothelial integrity/injury and increases risk of DVT/PE?
Smoking
Trauma
Surgery
(Endothelium normally secretes anticoagulant but not if damaged)
What affects venous stasis and increases risk of DVT/PE?
Immobility (long flights, after surgery)
Blood typically spreads out clotting factors with laminar flow but stasis leads to aggregation.
PE causes ___ _____
Increased Peripheral vascular resistance means increased RV strain to overcome this leading to ____ _____ _____ and finally RV failure secondary to increased pulmonary pressure
Cor pulmonale
Right ventricle hypertrophy
PE, pneumothorax and pneumonia all present with…
Pleuritic chest pain
Chest XR:
PE will look normal
Pneumonia and pneumothorax won’t!
How would a patient with a DVT present?
Unilateral swollen calf with engorged leg veins
Warm and oedematous
If complete occlusion of a large vein in DVT, what would you see?
Phlegmasia cerulea dolens = leg turns blue due to severe ischaemia
A Wells score of more than _ indicates a DVT is likely
1
(Calf swelling 3cm or more than other leg = 1 point
Pitting oedema = 1 point)
How is a DVT diagnosed?
If Wells score is less than 1 then do D-dimer test
If D-dimer raised or Wells score is 1+ then Duplex ultrasound (gold standard)
How do you treat a DVT?
Same as a non-massive PE:
DOAC like Apixaban or rivaroxaban
If DOAC is contraindication eg renal impairment, then give LMWH
Mobilisation and compression stockings
What is a differential diagnosis to a DVT?
Cellulitis (skin infection)
Tender, inflamed swollen calf with pronounced demarcation
What organisms typically causes cellulitis?
Staph aureus and strep pyogenes
How is cellulitis differentiated from DVT?
FBC shows leukocytosis (indicative of infection) with cellulitis but normal levels in DVT.
DVT will show D-dimer and duplex ultrasound will confirm.
What are symptoms of a PE?
Sudden onset pleuritic chest pain
Dyspnoea
Possibly haemoptysis
Evidence of DCT (swollen calf and immobilisation history)
Tachycardia
Hypotensive
Raised JVP
Ankle oedema
A Wells score of _ or more indicates a PE is likely
4
(eg. DVT evidence = 3 points
Tachycardia = 1.5 point)
How is a PE diagnosed?
D dimer and CTPA (pulmonary angiogram)
ECG shows sinus tachycardia and/or:
S1Q3T3 = major sign of cor pulmonale
T wave inversion of anterior and inferior leads
New RBBB
Chest XR = normal
What does S1Q3T2 mean?
A large S wave in lead 1 (ventricular depolarisation and contraction)
A Q wave in lead 3
An inverted T wave in lead 3
Indicates acute right heart strain possibly cor pulmonale or PE
What is cor pulmonale?
Condition characterised by enlargement and dysfunction of the right ventricle as a result of pulmonary hypertension.
Right sided heart failure
Increased pressure in right side means RV becomes enlarged and weakened, impairing ability to pump blood.
What is 1st line is the Wells PE score is 4 or lower?
D dimer test
If raised then do CTPA (gold standard)
What is done if the Wells PE score is greater than 4?
CTPA (pulmonary angiogram)
Why perform a D dimer test for diagnosing a PE?
Measure of clot burden, this small protein is released in blood when a blood clot is fibrinolysed
It is sensitive so rules PE in but is not specific as raised in many conditions so is not diagnostic
What is treatment for a massive PE?
Thrombolytics : Alteplase (clot buster))
What is treatment for a non-massive PE?
DOAC, 1st line = apixaban or Rivaroxaban
If contraindicated (eg renal impairment) then give LMWH
