This is the target population for TBI whole blood biomarkers. Because of the significant false-positive rate, TBI whole blood biomarker testing will be directed to casualties with moderate risk for intracranial hemorrhage. The goal is to allow symptomatic patients who test negative to forego CT scan and remain in place with activity restrictions (i.e. quarters, bed rest) and treatment of symptoms. There are two important caveats to this group:

1. The concussive event must have taken place within 24 hours of testing.
2. The patient should not have other injuries requiring urgent evacuation (fractures, concern for internal injuries, etc.). In this instance, testing should not hold up transport for more urgent issues but can still be completed.

Casualties without the high-risk red flag signs or symptoms described above but exhibit one or more of the following are appropriate candidates for TBI whole blood biomarker testing.

- Double vision
- Increased restlessness
- < 2 episodes of vomiting
- Subjective weakness or tingling in arms or legs but no clear focal neurological deficit
- Severe, persistent, or worsening headaches
- Age >60 years
- Anti-platelet drugs (such as aspirin or ibuprofen)
- Drug/alcohol intoxication
- Post traumatic amnesia (inability to recall events for 30 or more minutes after injury)
- Worrisome mechanism of injury: high speed motor vehicle collision or rollover; fall from greater than 3ft; or presence within 50m of a blast inside or outside.

Casualties with any of these findings should be evaluated with the TBI whole blood biomarker so long as the test is performed within 24 hours of the initial head injury. Then the forward provider contacts the TBI Biomarker Consultant (TMD, neurosurgeon or other neurospecialist, or via ADVISOR) and the two come to a decision regarding need for head CT and priority of evacuation. When it is determined that the patient can remain in place with activity restrictions and be treated per the treatment section below, the forward provider and consultant should make a plan to communicate on the patient’s progress.