Pulmonary embolism--assessment and management

Pulmonary embolism (PE) is a potentially life threatening disorder most commonly seen in debilitated patients with other common medical problems.

This article aims to increase the reader's understanding of the aetiology and pathophysiology of PE so as to identify particular at risk patients. An approach to investigation and management will also be explored.

Pulmonary embolism has an incidence of approximately two per 1000 per year, generally as a consequence of deep venous thrombosis (DVT), in the setting of immobility. Deep venous thrombosis and PE during a prolonged airline flight in an otherwise fit person is a rare event. Clinical assessment and simple investigations form the basis of initial evaluation. The confirmatory test is generally a ventilation/perfusion lung scan or a computerised tomography pulmonary angiogram. There is still considerable discussion as to which is the better test--both are valid if performed to acceptable standards--thus local factors often determine which is performed. Further tests may be needed in those with intermediate probability of PE after a confirmatory test. These patients, and those presenting with massive PE, may require pulmonary angiography (still regarded as the gold standard test). Treatment is anticoagulation, typically with low molecular weight heparin followed by 6 months of warfarin. Thrombolytic therapy is reserved for the acute massive presentation. Appropriate treatment reduces mortality substantially, however, rarely the clot remains unresolved and thromboembolic pulmonary hypertension (requiring expert evaluation) develops.