Role of the PE rule-out criteria (PERC) in patients with suspected pulmonary embolism (PE) in a UK District General Hospital

Abstract

Introduction: The PERC is proposed by the American College of Physicians guidelines to effectively exclude acute pulmonary embolism in low risk populations. 1 A PERC score of 0 suggests a low risk of PE and no further tests are required, whereas a score of ³1 would require further investigation. Defining low risk patients has been difficult and no consensus has been reached in Europe. 2 Method: Retrospective analysis using PERC was done in patients with low pre-test probability who underwent computer tomography pulmonary angiography (CTPA) for suspected PE in a district general hospital between September 2014 and August 2015. Results: 1150 patients had a diagnostic CTPA for suspected PE. Of these, 233 (20%) were positive. Of those with low Well9s score, 65 patients had PERC 0. 64 patients had a negative scan for PE. 1 patient had possible small sub-segmental PE, giving a combined negative predictive value of 99%. Conclusion: PERC is a useful tool to identify patients with low risk of PE if applied to those with a low pre-test probability even in centres with high prevalence of acute PE. Larger prospective studies are needed to validate this in Europe.