Acute pulmonary embolism: risk stratification

The death rate from acute pulmonary embolism (PE) exceeds the mortality rate for acute myocardial infarction. Risk stratification helps optimize the selection of those patients who will benefit from more aggressive therapy, such as thrombolysis or embolectomy, in addition to anticoagulation. The classic paradigm was to observe patients deteriorate and to attempt to maintain acceptable hemodynamics by starting vasopressors. If hemodynamics failed to improve or if cardiogenic shock persisted, thrombolysis or surgical embolectomy was considered. Sadly, this "watch and wait" approach often resulted in irreversible cardiogenic shock and multisystem organ failure. The new approach hinges upon rapid and accurate risk stratification. There are four features of this strategy: 1) clinical evaluation, 2) bedside nonimaging tests-electrocardiography and pulse oximetry, 3) imaging tests-echocardiography and chest computed tomography,and 4) cardiac biomarkers-such as the troponin level. When high-risk patients are identified,they can be triaged for urgent or emergent therapy, usually prior to developing overt hypotension and cardiogenic shock.