The Detection Of Plasma D-dimer Of Patients With Traumatic Brain Injury

Objective:To investigate the concentration, dynamic changes,the relation between the concentration of plasma D-dimer and the distance of midline shift on brain computed tomography (CT) and clinical signification of plasma D-dimer in patients with early traumatic brain injury.Methods:The concentration of plasma D-dimer in 96 patients with traumatic brain injury between Jan 2008 to Sep 2008 was measured by enzyme-linked fluorescent assay(ELFA).These patients were divided into three groups (minor, moderate and severe) according to the initial Glasgow coma scale(GCS). 30 health examination volunteers were admit at the same time as a control group. The 96 cases were also divided into four groups according to the distance of midline shift on brain computed tomography. The levels of plasma D-dimer were quantitatively dynamic measured in 96 patients. The prognosis was evaluated by plasma D-dimer according to Glasgow outcome scale (GOS) about 3 months after traumatic brain injury. Results:The concentration of plasma D-dimer in 96 patients with traumatic brain injury was significantly higher than that in control group (P<0.01).The level of plasma D-dimer were the highest in severe group, and moderate group were higher than minor group. The concentration of plasma D-dimer were gradually increased with the increasing of the midline-shift distance on CT. The concentration of plasma D-dimer were significantly increased at 72 hours after trauma than that within 12 hours in the patients who were accepted conservative treatment (P<0.01). The concentration of plasma D-dimer were significantly decreased at 168 hours than that at 72 hours (P<0.01), and the level of plasma D-dimer at 168 hours were also lower than that within 12 hours. The concentration of D-dimer correlated negatively with GCS and GOS(Correlation coefficients were r=-0.864, p<0.01;r=-0.853,p<0.01 respectively), which changed along with the condition of traumatic brain injury. Using ROC and AUC, we found the D-dimer level of the cut-off point to be approximately 6150ng/ml, with a good sensitivity of 83.8% and a specificity of 89.8% (AUC 0.942).Conclusion:The plasma D-dimer could be as a laboratory indicator for traumatic brain injury. The method is simple, specific and sensitive. It's a reliable way to evaluate the prognosis of traumatic brain injury by assaying the concentration of plasma D-dimer.