Recruitment not started due to potential conflicting study at same institution. May renew study in the future.

This study compares the efficacy and complication rates of early (24 hours) versus late (72 hours) VTE prophylaxis administration to TBI patients. Patients in both treatment groups will be monitored for development of VTE as well as complications from bleeding after commencement of VTE prophylaxis.

This a randomized prospective study that compares the efficacy and complication rates of early (24 hours) versus late (72 hours) VTE prophylaxis administration to TBI patients. Patients who are identified as having an intracranial injury will be randomized to early versus late VTE prophylaxis using a 1:1 random numbers allocation. Patients in both treatment groups will be monitored for development of VTE, primarily with scheduled duplex ultrasound studies of the lower extremities. Any clinical suspicion of VTE will also be investigated with duplex ultrasound and/or CT angiogram of the chest. Patients will be monitored for development of complications from bleeding post commencement of VTE prophylaxis. Intracranial bleeding complications will be monitored by physical examination and CT scanning of the head when indicated. Patients who undergo craniotomy or craniectomy will have VTE prophylaxis started 72 hours post-surgery and will undergo CT scan of the head (to assure bleeding stabilization) prior to administration of VTE prophylaxis.

Inclusion Criteria:

• Traumatic brain injury
• Intracranial hemorrhage on CT scan

Exclusion Criteria:

• Under the age of 18
• Pregnant
• Die within 24 hours of admission
• Hospital stay less than 5 days
• Contraindications to enoxaparin or heparin
• Coagulopathy at 24 hours post-injury defined as INR>1.6 aPTT>2x normal, or platelet counts<50k
• Known history of VTE