Is low-molecular-weight heparin safe for venous thromboembolism prophylaxis in patients with traumatic brain injury? A Western Trauma Association multicenter study.

Background: Venous thromboembolism (VTE) is a significant risk in trauma patients. Although low-molecular weight heparin (LMWH) is effective in VTE prophylaxis, its use for patients with traumatic intracranial hemorrhage remains controversial. The purpose of this study was to evaluate the safety of LMWH for VTE prophylaxis in blunt intracranial injury.

Methods: We conducted a retrospective multicenter study of LMWH chemoprophylaxis on patients with intracranial hemorrhage caused by blunt trauma. Patients with brain Abbreviated Injury Scale score of 3 or higher, age 18 years or older, and at least one repeated head computed tomographic scan were included. Patients with previous VTE; on preinjury anticoagulation; hospitalized for less than 48 hours; on heparin for VTE prophylaxis; or required emergent thoracic, abdominal, or vascular surgery at admission were excluded. Patients were divided into two groups: those who received LMWH and those who did not. The primary outcome was progression of intracranial hemorrhage on repeated head computed tomographic scan.

Results: The study included 1,215 patients, of which 220 patients (18.1%) received LMWH and 995 (81.9%) did not. Hemorrhage progression occurred in 239 of 995 control subjects and 93 of 220 LMWH patients (24% vs. 42%, p < 0.001). Hemorrhage progression occurred in 32 patients after initiating LMWH (14.5%). Nine of these patients (4.1%) required neurosurgical intervention for hemorrhage progression.

Conclusion: Patients receiving LMWH were at higher risk for hemorrhage progression. We were unable to demonstrate safety of LMWH for VTE prophylaxis in patients with brain injury. The risk of using LMWH may exceed its benefit.

Level Of Evidence: Therapeutic study, level IV.