Pulmonary embolism Flashcards
Risk factors
Immobility
Recent surgery
Long haul flights
Pregnancy
Hormone therapy with oestrogen
Malignancy
Polycythaemia
SLE
Thrombophilia
VTE prophylaxis
Any patient at increased risk of VTE
LMWH
ANti-embolic stockings
LMWH example
Enoxaparin
Contraindication to LMWH
Active bleeding
Existing anticoagulation with warfarin or a NOAC
Contraindication for compression stockings
Peripheral artery disease
Presentation
SOB
Cough (+/- haemoptysis)
Pleuritic chest pain
Hypoxia
Tachycardia
Raised RR
Low grade fever
Haemodynamic instability
Wells score
Predicts the risk of a patient presenting with symptoms actually having a DVT or PE
If likely perform CTPA
If unlikely perform d-dimer then if positive CTPA
Main options to establish definitive diagnosis
CTPA
VQ scan
CTPA
First line choice
More readily available
Gives information about alternatives such as pneumonia or malignancy
VQ scan
Used in patients with renal impairment, contrast allergy or at risk from radiation where a CTPA is unsuitable
ECG findings
Large S waves in lead 1
Large Q wave in lead 3
Inverted T wave in lead 3
(S1Q3T3)
RBBB and RAD
Sinus tachycardia
Chest xray
Recommended for all patients to exclude other pathology
Typically normal in PE
Possible wedge shaped opacification
VQ scan findings
Sensitivity around 75% and specificity 97%
Deficit in perfusion as thrombus blocks blood flow
Lung tissue will be ventilated but not perfused
Other causes of VQ mismatch
PE
AV malformations
Vasculitis
Previous radiotherapy
