Head Injury Management
Initial Assessment and Severity Classification
Management of head injury must be stratified by severity using the Glasgow Coma Scale (GCS), with immediate CT imaging for moderate-to-severe injuries (GCS ≤13) and selective imaging based on validated clinical decision rules for mild injuries (GCS 14-15). 1
Severity Classification
The motor component of the GCS is the most robust predictor, particularly in sedated patients, and pupillary size and reactivity are critical prognostic factors requiring repeated assessment. 2
Mild Head Injury (GCS 14-15)
Imaging Decision Rules
For mild head injury, CT scanning should be selective and guided by validated clinical decision rules rather than routine imaging of all patients. 1
Only 10% or less of mild head trauma cases show positive CT findings, and only 1% or less require neurosurgical intervention, making universal CT scanning inefficient. 1
High-Risk Criteria (Canadian CT Head Rule - 100% sensitive for neurosurgical intervention):
- Failure to reach GCS 15 within 2 hours 1
- Suspected open or depressed skull fracture 1
- Signs of basal skull fracture 1
- Vomiting more than once 1
- Age >64 years 1
Medium-Risk Criteria (98.4% sensitive for clinically important brain injury):
Patients with mild head injury and NO high-risk or medium-risk criteria can be safely discharged with written instructions and do not require CT imaging. 1, 3
Observation and Discharge
Patients with normal CT scans require only brief observation before discharge with warning instructions. 3 If CT is unavailable and skull X-ray is negative, patients can be discharged after observation. 3
Moderate-to-Severe Head Injury (GCS ≤13)
Immediate Neuroimaging
All patients with moderate or severe head injury require immediate non-contrast CT of the brain and cervical spine without delay to identify surgical lesions and guide management. 4, 2
- Use inframillimetric sections with dual windowing (brain and bone) 4
- Consider CT angiography for patients with cervical spine fractures, basal skull fractures, or focal deficits unexplained by brain imaging 4
Airway and Ventilation Management
Patients with severe TBI (GCS ≤8) require immediate tracheal intubation and mechanical ventilation with continuous end-tidal CO₂ monitoring. 1, 4
Ventilation Targets:
- PaO₂ ≥13 kPa (≥98 mmHg) - avoid even brief hypoxic episodes 1
- PaCO₂ 4.5-5.0 kPa (34-38 mmHg) 1
- Minimum PEEP 5 cmH₂O to prevent atelectasis; PEEP up to 10 cmH₂O does not adversely affect cerebral perfusion 1
Emergency hyperventilation (PaCO₂ not less than 4 kPa/30 mmHg) is justified only for impending uncal herniation and should be brief, combined with osmotic therapy. 1, 4
Hemodynamic Management
Maintain systolic blood pressure >110 mmHg (mean arterial pressure ≥80 mmHg) to ensure adequate cerebral perfusion. 4, 2
Hypotension (SBP <90 mmHg) dramatically increases mortality and morbidity, and the combination of hypotension with hypoxemia carries a 75% mortality rate. 2
Fluid Resuscitation:
- Use 0.9% normal saline exclusively - it is the only truly isotonic crystalloid solution 1
- Avoid Ringer's lactate, Ringer's acetate, and gelatins (hypotonic when measured by real osmolality) 1
- Do NOT use albumin or synthetic colloids in early management 1
- Reverse hypovolemia before transfer; never transfer hypotensive, actively bleeding patients 1
Blood Pressure Management:
- For hypotension after correcting hypovolemia: use α-agonist boluses (metaraminol) or noradrenaline infusion via central line 1
- For hypertension: increase sedation and use small labetalol boluses 1
- Measure arterial pressure at the level of the tragus, especially with head elevation 1
Patient Positioning
Position patients with 20-30° head-up tilt while maintaining spinal immobilization. 1
Intracranial Pressure Monitoring
ICP monitoring is indicated for severe TBI patients (GCS <9) with abnormal CT findings, particularly compressed basal cisterns, which is the strongest predictor of intracranial hypertension. 1
ICP >20-40 mmHg increases mortality risk 3.95-fold, and ICP >40 mmHg increases it 6.9-fold. 1
Management of Elevated ICP
First-Line Measures:
- Elevate head of bed 20-30° 4
- Restrict free water and avoid excess glucose 4
- Treat hyperthermia 4
- Optimize sedation and analgesia 1
- Correct hypoxemia and hypercarbia 4
Second-Line Interventions for Refractory ICP:
- External ventricular drainage for persistent intracranial hypertension 4, 2
- Mannitol 0.25-0.5 g/kg IV (or 0.5 g/kg per guidelines) 1, 4
- Hypertonic saline 2 ml/kg of 3% saline for clinical herniation 1, 4, 2
Neurosurgical Indications
Immediate surgical intervention is required for: 4
- Symptomatic extradural hematoma (any location)
- Acute subdural hematoma >5 mm thickness with >5 mm midline shift
- Acute hydrocephalus requiring drainage
- Open displaced skull fracture requiring closure
- Closed displaced skull fracture with brain compression
Decompressive craniectomy should be considered for refractory intracranial hypertension after multidisciplinary discussion. 1 Large temporal craniectomy (>100 cm²) with dural expansion can reduce mortality from 49% to 27% but may increase survival with severe disability. 1
Transfer Considerations
Transfer to a neurosurgical center must occur as quickly as possible after initial stabilization. 4 Patients must be hemodynamically stable, adequately oxygenated and ventilated, and have controlled bleeding before transfer. 1
Critical Pitfalls to Avoid
NEVER use corticosteroids for traumatic brain injury - they provide no mortality or neurological benefit. 4, 2
Deterioration after a lucid interval occurs in 71% of cases within 24 hours, with mass lesions found in 81% of these patients. 4 This mandates close observation even in initially stable patients.
Avoid permissive hypotension in TBI patients - unlike other trauma, brain injury requires maintained cerebral perfusion pressure. 1
Do not routinely hyperventilate - use only briefly for impending herniation as prolonged hyperventilation causes cerebral ischemia. 1, 4