Pulmonary embolism rule-out criteria: a clinical decision rule that works.

www.aafp.org/afp Volume 88, Number 2 ◆ July 15, 2013 Is there a clinical prediction rule that can reliably exclude the presence of a pulmonary embolism (PE), and thus avoid the use of computed tomography (CT) in patients believed to be at very low risk? Bob: Let’s start with a case. A 42-year-old woman presents to your clinic saying that she awoke that morning with pleuritic right infrascapular pain. It is not associated with cough, hemoptysis, fever, or chills. She has no anterior chest pain, leg pain or swelling, or shortness of breath at rest. She has not traveled recently. She takes no medications, and doesn’t use birth control pills. Her medical history is unremarkable, and she has no personal or family history of venous thromboembolism. Physical examination reveals normal vital signs, and she has good breath sounds bilaterally. A couple of causes for this patient’s discomfort quickly come to mind. Then you get this nagging thought: Could this be a PE? Although it’s very unlikely, you think: Should I just order the chest CT and stop worrying? This month’s article demonstrates the validity of the Pulmonary Embolism RuleOut Criteria (PERC; Table 11) and should reassure your decision to forgo CT in patients at very low risk of PE.