Lit Matters 2: Can we discharge mild TBI patients from the ED?

Mild traumatic brain injury is not synonymous with admission, repeat CT, or automatic neurosurgical consultation. For adults with minor head injury, current ACEP policy and the modified Brain Injury Guidelines support a more selective ED disposition strategy, including safe discharge for carefully defined low-risk patients.

Mild TBI Risk Stratification

• Adult mild TBI definition: ACEP defines mild TBI as GCS 14-15, with a GCS of 14 improving to 15 within 2 hours, with or without loss of consciousness, amnesia, or disorientation, and presentation within 24 hours of injury.
• Preferred head CT rule: The Canadian CT Head Rule carries the strongest ACEP endorsement for deciding who needs CT after minor head injury, with NEXUS Head CT and New Orleans Criteria offering lower specificity.
• Anticoagulation caution zone: Clinical decision tools should not be used to rule out CT in patients taking anticoagulants or antiplatelet agents other than aspirin, a key limitation that changes bedside decision-making.
• Post-concussion risk factors: Female sex, psychiatric history, intoxication, assault, loss of consciousness, and GCS below 15 all raise concern for post-concussive syndrome, while current biomarkers do not reliably predict it. We get into the follow-up nuances in the episode.

mBIG and ED Disposition

• mBIG clinical frame: The modified Brain Injury Guidelines are built to identify CT-positive TBI patients who can avoid routine repeat imaging and neurosurgical consultation after structured observation.
• Category-based disposition: mBIG sorts patients into three pathways based on exam, intoxication, anticoagulation, skull fracture, and hemorrhage pattern. We walk through the category logic in the chapter.
• Low-risk discharge concept: mBIG 1 is essentially an ED-to-home pathway after short observation, capturing patients with reassuring neurologic examination and small-volume intracranial hemorrhage.
• Resource use signal: After mBIG implementation, head CT use and neurosurgical consults dropped substantially, with fewer than two-thirds receiving repeat CT compared with nearly universal imaging before.
• Observed deterioration rate: Neurologic worsening during observation was uncommon at 1.6%, and most of those patients had clinical change without radiographic progression or need for intervention.
• System-level implementation: This is a workflow change, not a solo practice hack; mBIG works best as a shared ED-trauma-neurosurgery protocol, especially where transfer patterns and ICU use are driving over-triage.