Differentiating low-risk and no-risk PE patients: the PERC score.

BACKGROUND Pulmonary embolism (PE) remains one of the most challenging diagnoses in emergency medicine. The Pulmonary Embolism Rule-out Criteria (PERC) score, a decision aid to reliably distinguish low-risk from very low-risk PE patients, has been derived and validated. CLINICAL QUESTION Can a subset of patients with sufficiently low risk for PE be identified who require no diagnostic testing? EVIDENCE REVIEW The PERC score derivation and validation trials were located using PubMed and Web of Science. A critical appraisal of this research is presented. RESULTS One single-center and another multi-center validation trial both confirmed that the eight-item PERC score identified a very low-risk subset of patients in whom PE was clinically contemplated with a negative likelihood ratio 0.17 (95% confidence interval 0.11-0.25) in the larger trial. If applied, the rule would have identified 20% of potential PE patients as very low risk. CONCLUSION The PERC score provides clinicians with an easily remembered, validated clinical decision rule that allows physicians to forego diagnostic testing for pulmonary embolus in a very low-risk population.

[1]  P. Investigators,et al.  Value of the ventilation/perfusion scan in acute pulmonary embolism. Results of the prospective investigation of pulmonary embolism diagnosis (PIOPED). , 1990 .

[2]  H. Bounameaux,et al.  Effects of age on the performance of common diagnostic tests for pulmonary embolism. , 2000, The American journal of medicine.

[3]  A. Panju,et al.  Does this patient have pulmonary embolism? , 2003, JAMA.

[4]  J. Kline,et al.  Clinical criteria to prevent unnecessary diagnostic testing in emergency department patients with suspected pulmonary embolism , 2004, Journal of thrombosis and haemostasis : JTH.

[5]  G H Guyatt,et al.  Users' guides to the medical literature: XXII: how to use articles about clinical decision rules. Evidence-Based Medicine Working Group. , 2000, JAMA.

[6]  J. Kline,et al.  Prospective multicenter evaluation of the pulmonary embolism rule‐out criteria , 2008, Journal of thrombosis and haemostasis : JTH.

[7]  L. Tanoue.  Computed Tomography — An Increasing Source of Radiation Exposure , 2009 .

[8]  M Gent,et al.  Derivation of a Simple Clinical Model to Categorize Patients Probability of Pulmonary Embolism: Increasing the Models Utility with the SimpliRED D-dimer , 2000, Thrombosis and Haemostasis.

[9]  J. Haukoos,et al.  Assessment of the pulmonary embolism rule-out criteria rule for evaluation of suspected pulmonary embolism in the emergency department. , 2008, The American journal of emergency medicine.

[10]  I. Stiell,et al.  The interobserver reliability of pretest probability assessment in patients with suspected pulmonary embolism. , 2005, Thrombosis research.

[11]  J. Kassirer,et al.  The threshold approach to clinical decision making. , 1980, The New England journal of medicine.

[12]  S. Silvers,et al.  Clinical policy: critical issues in the evaluation and management of adult patients presenting with suspected pulmonary embolism. , 2003, Annals of emergency medicine.

[13]  J. Douketis,et al.  An Evaluation of d-Dimer in the Diagnosis of Pulmonary Embolism , 2006, Annals of Internal Medicine.