pulmonary embolism rule-out criteria (the PERC rule)

Last edited 05/2020 and last reviewed 01/2021

Pulmonary embolism rule-out criteria (the PERC rule)

• if clinical suspicion of PE is low[1], consider using the pulmonary embolism rule-out criteria (PERC) to help determine whether any further investigations for PE are needed

[1] The clinician estimates the likelihood of PE to be less than 15% based on the overall clinical impression and other diagnoses are feasible.

NICE noted that "In people with signs or symptoms of PE, but in whom clinical suspicion of PE is low (the clinician estimates the likelihood of PE to be less than 15% based on the overall clinical impression and other diagnoses are feasible), there was some evidence showing that the PERC rule can accurately eliminate PE as a possible diagnosis. The committee agreed that using the PERC rule can reduce anxiety and avoid unnecessary D-dimer testing, imaging and interim anticoagulation treatment for people with a low probability of PE and none of the PERC criteria for PE. However, the evidence was limited so the committee agreed to recommend that the PERC rule be considered as part of initial assessment."

Reference:

• NICE (March 2020). Venous thromboembolic diseases: diagnosis, management and thrombophilia testing.