The diagnosis of pulmonary embolism in patients with normal d-dimer levels

Abstract

Introduction: the combination of clinical probability assessment and the D-dimer test has been recommended to avoid unnecessary diagnostic testing in pulmonary thromboembolism (PTE). However, in clinical practice, patients are occasionally diagnosed with PTE despite normal D-dieter levels. in the present study, we reviewed the characteristics of cases in an emergency department (ED) in which a diagnosis of PTE was made despite normal D-dimer test results. Materials and methods: the hospital records of 107 patients who were admitted to the ED of a teaching hospital and diagnosed with PTE between January 2011 and December 2013 were reviewed retrospectively. We acquired data for 11 patients (10.2%) in whom D-dimer measurements obtained by an automated latex turbidimetric quantitative method were below 500 ng/ml (0-450). Results: of the 11 patients, 72.7% (8/11) were female, and mean age was 71. +/- 57.9 (61-84) years. the most common symptom was dyspnea (54.5%, n=6). the mean delay between onset of symptoms and admission to the ED was 10.6 (3-30) days, and follow-ups were performed for patients in other health facilities for various causes of dyspnea. When risk factors were analyzed with the Wells score, 18.2% (2/11) of patients had low probability of PTE, whereas 72.7% (8/11) had intermediate, and 9% (1/11) had high probability. According to the revised Geneva score, 18.2% (2/11) of patients were found to have low probability, and 81.8% (9/11) had intermediate probability. the Pulmonary Embolism Severity Index score classified 18.2% (2/11) of the patients in the low risk group, and the European Society of Cardiology classification classified 81.8% (9/11) in the low risk group. Conclusion: in patients with nonspecific symptoms of PTE, the delay between onset of symptoms and admission to the ED is important. the risk factors of the patients and their pre-test probabilities should be considered along with D-dieter test results.