A RAPID ASSAY FOR THE DETECTION OF CIRCULATING D-DIMER IS ASSOCIATED WITH CLINICAL OUTCOMES AMONG CRITICALLY-ILL PATIENTS

Objective: To determine whether the results of a rapid, semiquantitati ve assay for the detection of circulating D dimer in whole blood (SRDD assay) are associated with the occurrence of clinical outcomes among critically ill patients.Design: Prospective, blinded, single-center st udy. Setting: Medical intensive care unit (ICU) of Barnes-Jewish Hospi tal, St. Louis, MO, a university-affiliated teaching hospital. Patient s: Three hundred twenty-three adult patients admitted to a medical ICU .Interventions: Collection of blood samples within 24 hrs of ICU admis sion. Measurements and Main Results: The main outcome measures evaluat ed included vascular thrombosis, hospital mortality, and the developme nt of multiorgan dysfunction. Fifty (15.5%) patients were found to hav e increased concentrations of D-dimer as detected by the SRDD assay wi thin 24 hrs of ICU admission. The concentrations of plasma D-dimer sim ultaneously measured by an enzyme immunoassay based on the same antibo dy were significantly greater among patients with a positive SRDD assa y compared with patients with a negative SRDD assay (1214 +/- 483 vs. 405 +/- 407 ng/mL; p <.001). The hospital mortality rate was significa ntly greater among SRDD-positive patients compared with SRDD-negative patients (32.0% vs. 15.0%; p=.004). SRDD-positive patients also had si gnificantly greater frequencies of acquired multiorgan dysfunction (48 .0% vs. 17.6%; p <.001), severe sepsis or septic shock (56.0% vs. 20.9 %; p<.001), and vascular thrombosis (14.0% vs. 4.0%; p=.005) compared with SRDD negative patients. Multiple logistic regression analysis ide ntified the presence of increased concentrations of D dimer, detected by a positive SRDD assay, as being independently associated with vascu lar thrombosis (adjusted odds ratio 5.06; 95% confidence interval 2.96 to 8.65; p=.003) and the development of multiorgan dysfunction (adjus ted odds ratio 1.51; 95% confidence interval 1.28 to 1.78; p=.012). Co nclusions: Our preliminary investigation suggests that the results fro m a rapid whole blood assay for the semiquantitative detection of circ ulating D-dimer are associated with clinical outcomes among patients a dmitted to a medical ICU. In addition, the use of D-dimer to identify the presence of active intravascular thrombosis may identify patients likely to benefit from antithrombotic therapies in the ICU setting.