Deep venous thrombosis (DVT) and its complications are recognized and common problems in trauma patients, particularly those with traumatic brain injury (TBI). We know that giving chemical prophylaxis like heparin and low molecular weight heparin (LMWH) reduces the risk. Unfortunately, trauma professionals (and neurosurgeons in particular) are reluctant to give it after acute TBI for fear of making intracranial hemorrhage worse.
Froedtert Hospital in Milwaukee modified their protocol for TBI patients to allow chemical prophylaxis to start 24 to 48 hours after a 24 hour followup CT that showed no progression of any bleeding. Therefore, prophylaxis could be started 48 to 72 hours after injury. They used subq heparin three times daily, or LMWH twice daily. All others received mechanical prophylaxis and were screened twice weekly by duplex ultrasound. The chemical prophylaxis group was not screened routinely.
A total of 812 patients were studied, half of whom received early prophylaxis per protocol. The average Abbreviated Injury Score for the head in these patients was 3.4, which represents fairly serious injury. There was a significant decrease in the incidence of DVT in the chemical prophylaxis group (1% vs 3%). More intriguing, there was a lower rate of injury progression in this group as well (3% vs 6%), although not quite statistically significant.
Bottom line: Although this is a small and retrospective study, it was well designed and relatively large compared to most other similar work. It shows that use of chemical prophylaxis works in patients with serious TBI, and appears to be safe. Similar protocols should be considered by trauma program multidisciplinary operations committees to further systematize this process.
Reference: Safety and efficacy of prophylactic anticoagulation in patients with traumatic brain injury. J Am Coll Surg 213:148-154, 2011.
Related post: Does interrupting DVT prophylaxis increase risk for it?