ECG may show: tachycardia; RV strain, i.e. T-wave inversion in right precordial and inferior leads; RBBB; right axis deviation; S1Q3T3; RA enlargement, i.e. P pulmonale; RV dilation, i.e. dominant R in V1
Echocardiogram: right ventriclar dysfunction/dilation
Troponin: higher mortality risk if raised
Consider looking for cause if unprovoked PE
Malignancy: undertake history, examination and basic blood tests (FBC, U&Es, LFTs, coagulation screen); further investigations only if relevant symptoms/signs
Antiphospholipid syndrome: check antiphospholipid antibodies if antiphospholipid syndrome suspected
Hereditary thrombophilia: consider testing if first-degree relative also has DVT or PE
Calculate the two-level PE Wells score to predict the likelihood of PE. This score takes into account risk factors (recent surgery/immobility, previous VTE, cancer), symptoms of VTE (DVT symptoms, HR, haemoptysis), and the likelihood of alternative diagnosis (Wells et al. 2001).
Therapeutic anticoagulant options
LMWH: usually given initially in larger PEs until vital signs have normalised, incase patient deteriorates and thrombolysis is required (DOAC is relative contraindication). Not usually used long term because patient will have to give daily self-injections.
DOACs: most commonly used anticoagulation. Rivaroxaban and apixaban are preferred and have loading doses; edoxaban and dabigatran do not have loading doses and so are started after 5 days of LMWH.
Warfarin: usually used where DOACs are contraindicated (e.g. renal impairment, body weight >120kg). If using warfarin, continue LMWH until had ≥5 days dual therapy and is INR 2-3.
Thrombolysis and other interventions
‘High-risk’ PE (persistent hypotension, obstructive shock or cardiac arrest) → immediate thrombolysis
‘Intermediate-risk’ PE (haemodynamically stable, but with RV dysfunction and/or myocardial necrosis) → consider heparin infusion initially, so thrombolysis can be given more safely if patient develops high-risk features
NB: thrombolysis is followed by an unfractionated heparin infusion. If thrombolysis is contraindicated or fails, other options such as surgical embolectomy or percutaneous catheter-directed treatment can be considered.