[Comparison of a D-dimer rapid-test with a plasma-immunoassay for diagnosis of venous thrombosis or pulmonary embolism in a medical emergency unit].
The level of D-dimer in the blood reflects the level of lysed, cross-linked fibrin, and is useful in the diagnosis of clinically suspected deep venous thrombosis and pulmonary embolism. We compared two assays for the measurement of D-dimer levels, the whole-blood immunoassay SimpliRED which can be performed in two minutes, and the plasma immunoassay NycoCard. D-dimer levels were determined with these two techniques in 100 patients. With clinically suspected deep vein thrombosis and positive D-dimer levels a compression ultrasonography using a colour coded Duplex instrument, or a phlebography were done. For clinically suspected pulmonary embolism a ventilation/perfusion scan was done in patients with normal x-ray. Patients with radiographic abnormalities were investigated with spiral computed tomography or pulmonary arteriography. When both assays showed negative results a diagnostic procedure was only done if there was a high clinical suspicion for thromboembolism. Both assays showed a correct positive result in seven of the eight diagnosed thromboembolic events and one false negative result each. The SimpliRED assay exhibited a sensitivity of 87.5% and a specificity of 61%, the negative predictive value was 98.3%, positive predictive value 15.9%. The NycoCard assay displayed also a sensitivity of 87.5%, specificity was lower with 39.6%, the negative predictive value was 97.4%, positive predictive value 10.7%. The SimpliRED assay can be a valuable tool when laboratory facilities for a plasma immunoassay are not accessible. The negative predictive value is very high, therefore this test is considered to be helpful for excluding a thromboembolic event.
Stey
C
C
Medizinische Poliklinik, Universitätsspital Zürich. claudia.stey@DIM.usz.ch
Steurer
J
J
Fehr
J
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D020246:Venous Thrombosis / Q000175:diagnosis*
D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D