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)

Bottom line:

• 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.