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?
Field Concussion Testing For Athletes
Public awareness of concussions, particular those from sports, is on the rise. It’s difficult enough for trauma professionals to diagnose some of the milder forms of head injury. Expecting lay people to do this is just not realistic.
Most people have heard of ImPACT testing for head injury. This involves determining a player’s baseline ability to remember a series of words. It tests memory, attention span and reaction time. A baseline study is required, and the test takes about 20 minutes to administer using a computer.
The King-Devick test is a numerical processing tool that can be administered using an iPad or a deck of cards. A baseline value is required as well, and the test takes about 2 minutes to administer. See the video for details.
Both tests have been validated by a number of scientific studies, and both are only available for purchase. Several hospitals, trauma centers, and schools have purchased the programs and will administer them for free.
Check out these valuable programs and consider providing them at your own local sporting events.
Related post: TBI screening with the Short Blessed Test
Coagulopathy is a frequent occurrence after severe traumatic brain injury (TBI). There are high levels of tissue factor (TF) in the brain, which can be released with severe injury. This in turn triggers a cascade which can lead to generalized coagulopathy.
The trauma group at LAC+USC looked at the time course of coagulopathy after isolated severe TBI. They identified 278 patients over a 1.5 year period and retrospectively review a number of demographic and outcome variables. Coagulopathy was defined as a platelet count < 100,000/mm3, INR > 1.4, or PTT > 36 sec.
They found the following:
- 46% with blunt trauma and 82% with penetrating injury developed a coagulopathy
- Presence of coagulopathy increased with increasing head injury severity
- Thromobocytopenia as a cause of coagulopathy was less common (17%) than clotting factor problems
- As brain injury severity increased from AIS=3 to AIS=5, median onset of coagulopathy became increasingly earlier (26 hrs, 22 hrs, 10 hrs)
- Mortality increased with earlier coagulopathy (23% after 24 hrs, 39% between 12 and 24 hrs, 56% less than 12 hrs)
- Prehospital: Coagulopathy should be suspected if the patient is bleeding profusely from multiple sites, including your IV needle sticks. This indicates severe brain injury and demands triage to a trauma center with immediate neurosurgical support.
- In-hospital: Coagulopathy that is noted in the ED portends severe injury and poor prognosis. Rapid access to CT scan and your neurosurgical consultant is critical.
Related post: Controlling fever in head injury
Reference: Time course of coagulopathy in isolated severe traumatic brain injury. Injury 41:924-928, 2010.
Seatbelt use has increased from 58% in 1994 to a high of 85% last year. We know that seatbelt use saves lives, but trauma professionals are also aware that they can create their own injuries as well. This is a positive trade-off, because belt use prevents injuries that are difficult to treat (e.g. severe brain injury) and produces a higher number of intra-abdominal injuries that are easy to treat.
The spectrum of injuries attributed to seat belt use was finally appreciated in a journal article published 20 years ago this month. The authors wanted to catalog the various injuries seen in belted and unbelted motor vehicle occupants. They reviewed data from the North Carolina Trauma Registry, one of the most sophisticated state registries at the time. Although there were over 21,000 records in the database, only 3,901 involved motor vehicle crashes and had complete data on seatbelt use.
This study found the following:
- Mortality was higher in those not wearing their seat belts (7% vs 3.2%)
- Unbelted had a much higher incidence of severe head injury (50% vs 33%)
- Overall incidence of any abdominal injury was the same for both (14%)
- GI tract injuries were more common in the belted group (3.4% vs 1.8%)
- Solid organ injury was the same
Bottom line: This study sparked the recognition that seatbelts reduce severe head injury but increase the incidence of some hollow viscus injuries. About 514 severe head injuries were prevented in exchange for 21 additional abdominal injuries that were generally easily repaired. Good tradeoff!
Reference: The spectrum of abdominal injuries associates with the use of seat belts. J Trauma 31(6):821-826, 1991.
Concussion Testing: There’s An App For That!
Smart phone programmers are becoming more and more creative! The newest trauma app is geared toward helping the user identify individuals who have suffered a concussion. It can be used by parents, coaches or physicians to help identify a concussion at sporting events.
The app is a portable and convenient system for identifying concussions based on established sports medicine research. It queries the user for common signs of concussion, tallies the results of a simple balance test, and looks for other symptoms that suggestion the injury. The exam can also be administered serially to detect changes from baseline.
To get the most from this free app, the user must purchase an optional module for $4.99 that does a more in-depth physiologic and cognitive evaluation. A report can be emailed automatically to your physician, and he or she can then respond and send a message to your team to approve or deny continuing play.
The app is provided by SportSafety Labs LLC. The basic app is free, and the add-on is $4.99. It is published for the iPhone and iPad.
Bottom line: Expect more trauma-oriented apps geared toward a variety of problems in the near future!
To get more information on this app, click here.