52. Contrasting post-traumatic serial changes for D-dimer and PAI-1 in critically injured patients

We measured D-dimer and plasminogen activator inhibitor-1 (PAI-1) activity in 45 trauma patients to assess their efficacy in predicting the post-traumatic hemostatic perturbations. We found the correlation between D-dimer measured by Simpli Red test and ELISA to be highly significant (p=0.0001). The D-dimer ELISA indicated that the serial changes of D-dimer after trauma were variable. However, the increases of D-dimer were associated with clinical conditions of the patient, such as trauma surgery, infections, or thrombotic complications. A significant correlation was found for D-dimer levels measured by ELISA versus the injury severity score (ISS) in all the trauma patients on day 1 (p=0.0153) and on day 2 (p=0.0495). The PAI-1 activity was increased at admission and showed a progessive decline from day 2 onward, and the correlation for the daily decline of PAI-1 was highly significant (p=0.0001). The PAI-1 activity and plasminogen activator activity showed a significant negative correlation on days 1, 2, and 3. PAI-1 activity correlated moderately with D-dimer level only on day 1 (p=0.0569). Three out of forty-five patients developed thrombotic complications: one patient who died from pulmonary embolism and two patients who developed adult respiratory distress syndrome (ARDS). In summary: 1) PAI-1 activity and D-dimer exhibited contrasting serial changes after trauma. 2) There was also a negative correlation between PAI-1 activity and PA activity. 3) A significant correlation of D-dimer with ISS confirms, as might be anticipated, that there is increased activation of the coagulation mechanism in severe injury, and suggests that D-dimer levels may prove useful to screen for patients at strong risks of thrombotic complications.