Value of Prothrombin Fragment F1+2 in the Diagnosis of Pulmonary Embolism in Patients With Chronic Obstructive Pulmonary Disease (COPD) Exacerbation

To access the clinical usefulness of F1+2 in the diagnosis of PE in patients with AECOPD who require hospitalization. Specifically, to determine whether F1+2 may have an additional value in the subgroup of patients with an abnormal D-dimer,to determine whether it may increase the proportion of patients in whom PE can be safely ruled out and to determine the sensitivity, specificity and NPV of F1+2 at various cut-off values.