Management of patients with suspected deep vein thrombosis in the Emergency Department: Combining use of a clinical diagnosis model with D-dimer testing

The management of patients presenting to hospital Emergency Departments wit h suspected deep vein thrombosis is problematic since urgent diagnostic ima ging is at times unavailable. We evaluated the accuracy of a rapidly availa ble D-dimer test and the potential of combining D-dimer testing with an exp licit clinical model to improve the management of patients with suspected d eep vein thrombosis. Two hundred and fourteen patients with suspected deep vein thrombosis presenting to the Emergency Departments of two tertiary car e institutions were enrolled in this prospective cohort study. Patients wer e evaluated by an Emergency Physician who determined the pre-test probabili ty for deep vein thrombosis to be either low, moderate, or high using an ex plicit clinical model. Patients were managed according to their pre-test pr obability category by specific algorithms that in all cases included venous ultrasound imaging within 24 h and a 90-day follow-up for the development of thromboembolic complications. Patients also underwent fingerstick Simpli RED(R) whole blood agglutination D-diner testing; however, D-dimer results did not influence subsequent patient management. D-dimer had a sensitivity of 82.5% and a specificity of 84.9% for the diagnosis of deep vein thrombos is. The observed negative predictive value of D dimer was 96.9% (95% CI, 93 .0% to 99.1%) overall, and 100% (95% CI, 96.3% to 100%) in low probability patients, 94.1% (95% CI, 83.8% to 98.8%) in moderate probability patients, and 86.7% (95% CI, 59.4% to 98.3%) in high probability patients. SimpliRED( R) D-dimer has it high negative predictive value and may be useful in exclu ding the diagnosis in patients at low pre-test probability for deep vein th rombosis. (C) 2000 Elsevier Science Inc.