The information obtained from the history, examination and investigations performed in the ED will identify a group of patients in whom an alternative diagnosis can be confidently made thereby precluding the need for further investigation for PE.

For those patients in whom an alternative diagnosis cannot confidently be made, risk stratification (using information in the history and examination) must be performed to assign a clinical probability of PE to the patient and to determine the best strategy for excluding PE.

The most widely used risk stratification tools are:

  • Wells’ criteria5
  • Revised Geneva Score9 or Simplified Revised Geneva Score10
  • Pulmonary Embolus Rule-Out Criteria (PERC)11

We will look at each of these in turn.