The impact of enoxaparin administration in relationship to hemorrhage in mild traumatic brain injury.

BACKGROUND: Venous thromboembolism prophylaxis in the general trauma population is well established. However, risk of increased intracranial hemorrhage in traumatic brain injury (TBI) population is of concern. The aim for this study is to identify a reproducible model of mild traumatic brain injury (mTBI), evaluated by clinical and histological markers and test the hypothesis that enoxaparin increases the risk of spontaneous brain hemorrhage.

METHODS: 40 male Sprague Dawley rats were randomly assigned to 5 groups: group 1 (sham) with no TBI along with 4 groups comparing mTBI with and without pharmacological intervention using enoxaparin at 24 h and 72 h respectively. Mild traumatic brain injury was induced using a weight drop apparatus, with a clinical endpoint of time to right (TTR), along with histological and spectrophotometer analysis for qualitative hemorrhage.

RESULTS: There is a statistically significant difference between group 1 (sham) and all other groups with a mean longer time to right of 64 s (p = 0.005) in the mTBI groups. There was a statistically significant difference between group 1 (sham) and all other groups with an increase of 6 g/dL hemoglobin (p < 0.001) in the mTBI groups with no difference in hemorrhage between groups that were treated with enoxaparin.

CONCLUSION: The weight drop apparatus is a reproducible model for mTBI that has correlations with clinical and qualitative data. This model was able to produce clinical signs of concussion, as reflected by longer TTR and increased hemoglobin in the mTBI groups. Upon further analysis, there wasno increase in hemorrhage in the pharmacological intervention groups with enoxaparin.