Quick reference algorithm

BIG Classification — TBI Management

Head injury patients age ≥ 15 with CT completed · March 2026 edition

Age ≥ 15 · CT completed

Brain Injury Guidelines for head injury patients

Head injury patient — classify per BIG criteria

Based on GCS, bleed size, and anticoagulation status

Age ≥ 15 · CT completed

BIG 1ED observation ↓BIG 2ICU or floor ↓BIG 3ICU admission ↓

BIG 1

ED observation

Criteria

GCS 15
Small bleeds
No anticoagulation

ED observation

6 hours, neuro checks q2h
Repeat CT at 6 h if on antiplatelets

GCS 15? No worsening?

Yes

Discharge

Head injury precautions

Return if:

Headache worsens
Vomiting
Confusion
Weakness
Seizure

No (GCS < 15 or worsening)

Worsening?

Reclassify & repeat CT →

Escalate to BIG 3 if needed

BIG 2

ICU or floor

Criteria

GCS 13–15
Moderate bleeds
No anticoagulation

ICU triggers?

Age ≥ 65
SDH ≥ 6 mm
Antiplatelet use
Multiple bleeds
Coagulopathy
Intoxication

Any trigger

ICU admission

Neuro checks q2h
Consider seizure prophylaxis

None

Floor admission

Neuro checks q2h

Worsening?

Reclassify & repeat CT
Escalate to BIG 3 if needed

Also entered from BIG 1 when “GCS 15? No worsening?” is No.

BIG 3

ICU admission

Criteria

GCS ≤ 12
Large bleeds
OR anticoagulated

ICU admission

Neurosurgery consult within 30 min
Neuro checks q1h
Seizure prophylaxis: Levetiracetam 1 g IV q12h × 7 days

Anticoagulated?

Yes

Reversal protocol

Factor Xa inhibitors → 4F-PCC
Dabigatran → Idarucizumab
Warfarin → PCC + Vitamin K

PCC thrombosis risk ~3.8%

Monitor for VTE/PE/MI

Standard ICU

Management per TBI protocol

Repeat imaging and step-down

Repeat CT

At 6–24 h or with any neurological decline

Step-down criteria met?

GCS ≥ 13 × 24 h
Stable CT
No NSC intervention
NSC agrees

NSC = neurosurgery

Yes

Transfer to floor

Neuro checks q2h

Continue ICU

Reassess daily