Embolus in the pulmonary vasculature that has classically travelled from a deep vein of the leg (DVT) via the right heart or a right atrial thrombus in AF.

Virchow’s Triad:

Venous stasis e.g. immobility, CCF, dehydration and venous obstruction

Endothelial Injury e.g. trauma, inflammation and previous thrombosis

Hypercoagulable state e.g. malignancy, oestrogen therapy, surgery and  

abnormalities of the clotting cascade

Acute Minor: hyperventilation, haemoptysis, hypoxia, fever, effusion

Acute Major: As above + hypotension, cyanosis, engorged neck veins and collapse

Sub-Acute/Chronic: hyperventilation, raised JVP

Acute Minor: Pleuritic pain, dyspnoea

Acute Major: Central chest pain, dyspnoea

Sub-Acute/Chronic: Progressive dyspnoea

Chest X-Ray: Often normal, elevation of a hemi-diaphragm and linear atelectasis, 

small effusions or wedged shaped infarcts may be present

ECG: Sinus tachycardia, right heart strain or S1Q3T3

ABG: Low PaO2 and PaCO2

D-dimer: If clinical probability is intermediate or low then a negative d-dimer is a 

reliable rule-out of thromboembolic disease

CTPA: Initial investigation for non-massive PE’s

V/Q Scan: Used in those who can not tolerate CT contrast 

Thrombolysis: Clinically massive PE and marked haemodynamic compromise

Anticoagulation: Low molecular weight heparin then Warfarin with a target INR of 2.0-3.0. 

LMWH continued until 2 consecutive days of target INR achieved due to initial prothrombotic effect of Warfarin.

IVC filter: Aim to prevent further clot reaching pulmonary vasculature

Pulmonary haemorrhage, pulmonary hypertension, CCF, recurrent episodes