Whole blood D-dimer assay: An effective noninvasive method to rule out pulmonary embolism

Background: The whole blood D-dimer assay has gained recognition as a nonin vasive test to rule out pulmonary embolism BE) in medical patients. Methods: We performed a whole blood D-dimer assay in medical and surgical p atients undergoing either pulmonary angiogram or pulmonary ventilation perf usion scan for suspected PE or duplex Doppler or venogram for suspected dee p venous thrombosis DVT). Results: A total of 483 patients were enrolled; 16 were excluded because of an equivocal pulmonary ventilation perfusion scan. The 467 remaining patie nts had a mean age of 56 +/- 27 years. There mere 258 women and 209 men. A total of 353 patients were admitted to a medical service and 114 to surgery / trauma. A total of 82 patients (18%) developed thromboembolism: 20 had PE , and 62 had DVT. Conclusion: No surgical patient with PE or DVT (n = 27) had a negative D-di mer. A negative D-dimer result in a stable surgical patient should be consi dered conclusive evidence to rule out thromboembolism and, thus, negate the need for further diagnostic studies. In our surgical patients suspected of DVT or PE, had D-dimer been used, one third of the patients would have avo ided an expensive or invasive diagnostic test.