What is the appropriate management for a patient with a head injury, including evaluation, treatment, and potential complications?

Head Injury Management

Initial Assessment and Stabilization

Airway control is the absolute first priority—secure the airway via tracheal intubation for any patient with Glasgow Coma Scale (GCS) ≤8, and maintain mechanical ventilation with end-tidal CO₂ monitoring even during pre-hospital transport. 1, 2

Pre-Hospital Priorities

• Maintain systolic blood pressure >100 mmHg (or mean arterial pressure >80 mmHg) to prevent secondary brain injury from hypotension, which significantly worsens outcomes 1, 2, 3
• Target PaO₂ of 60-100 mmHg and PaCO₂ of 35-40 mmHg (4.5-5.0 kPa) to avoid cerebral vasoconstriction and ischemia 1, 3
• Assume cervical spine injury in any unconscious patient and maintain full spinal immobilization until neurologic function is assessed and neck pain/tenderness excluded 2
• Transport immediately to a trauma center with neurosurgical capabilities—outcomes are significantly better when severe traumatic brain injury patients are managed at specialized centers 2

Emergency Department Evaluation Algorithm

Perform urgent neurological evaluation immediately upon arrival, including GCS score (with specific attention to motor response), bilateral pupillary size and reactivity, and obtain non-contrast brain CT scan without delay. 1, 2, 3

Critical "Red Flags" Requiring Immediate Neurosurgical Consultation

• Persistent altered mental status or worsening level of consciousness 2
• Severe or progressively worsening headache 2
• Repeated vomiting (>2 episodes) 1, 2
• Seizure activity 2
• Focal neurological deficits 2
• Signs of cerebral herniation (pupillary abnormalities, posturing) 2

Risk Stratification for Mild Head Injury (GCS 13-15)

Use validated clinical decision rules (Canadian CT Head Rule or New Orleans Criteria) to determine which patients require CT imaging. 1

High-Risk Factors Mandating CT (Canadian CT Head Rule)

• Failure to reach GCS score of 15 within 2 hours of injury 1
• Suspected open or depressed skull fracture 1
• Any sign of basal skull fracture (hemotympanum, raccoon eyes, Battle's sign, CSF leak) 1
• Vomiting more than once 1
• Age >64 years 1

These high-risk factors are 100% sensitive (95% CI 92-100%) for predicting need for neurosurgical intervention. 1

Medium-Risk Factors for Clinically Important Brain Injury

• Amnesia before impact >30 minutes 1
• Dangerous mechanism of injury (pedestrian struck, ejection from vehicle, fall from >3 feet or 5 stairs) 1

Management Based on CT Findings

Surgical Lesions Requiring Immediate Neurosurgical Intervention

If CT reveals epidural hematoma, acute subdural hematoma with thickness >5mm and midline shift >5mm, or depressed skull fracture, obtain immediate neurosurgical consultation. 1, 2, 3

Additional surgical indications include: 1

• Symptomatic extradural hematoma (any location)
• Acute hydrocephalus requiring drainage
• Open displaced skull fracture requiring closure
• Closed displaced skull fracture with brain compression (thickness >5mm, mass effect with midline shift >5mm)

Intracranial Pressure Monitoring Indications

Place ICP monitoring in comatose patients with radiological signs of intracranial hypertension, regardless of whether they need other emergency surgeries. 1, 3

• Target cerebral perfusion pressure (CPP) ≥60 mmHg when ICP monitoring is available 3
• Consider external ventricular drainage for persisting intracranial hypertension despite sedation and correction of secondary brain insults 1, 3

Refractory Intracranial Hypertension

Consider decompressive craniectomy (>100 cm² temporal craniectomy with enlarged dura mater plasty) for refractory intracranial hypertension after multidisciplinary discussion. 1

This should be considered when first-line treatments (sedation, CSF drainage, osmotic therapy) have failed. 1

Positioning and Ventilation During Transport

• Position patient with 20-30° head-up tilt while maintaining spinal immobilization 1
• Target PaO₂ ≥13 kPa and PaCO₂ 4.5-5.0 kPa during mechanical ventilation 1
• Use minimum 5 cmH₂O PEEP to prevent atelectasis; PEEP up to 10 cmH₂O does not adversely affect cerebral perfusion 1

Avoid hyperventilation except for short-term use in impending uncal herniation (maintain PaCO₂ not less than 4 kPa), combined with osmotic therapy (mannitol 0.5 g/kg or hypertonic saline 2 ml/kg of 3% saline). 1

Fluid Management

Use only 0.9% saline for fluid resuscitation—it is the only commonly available isotonic crystalloid solution appropriate for brain injury. 1

• Avoid Ringer's lactate, Ringer's acetate, and synthetic colloids (gelatins, albumin)—these are hypotonic when real osmolality is measured and can increase brain water 1
• Correct hypovolemia before transport—hypovolemic brain-injured patients do not tolerate transfer well 1
• Never transport a hypotensive, actively bleeding patient—control hemorrhage takes precedence over transfer 1

Blood Pressure Management

Measure all invasive arterial blood pressure with transducer at the level of the tragus (including when patient is positioned head-up). 1

• For hypotension after correcting hypovolemia: use small boluses of α-agonist (metaraminol) followed by infusion, or noradrenaline via central line 1
• For hypertension: increase sedation first, then use small boluses of labetalol 1

Short-Term Follow-Up Imaging

For any trauma patient with neurologic deterioration, obtain head CT immediately regardless of whether initial imaging was positive or negative. 1

• Brain MRI is indicated as second-line study when persistent neurologic deficits remain unexplained after head CT 1
• MRI is more sensitive than CT for subtle findings adjacent to calvarium/skull base (small cortical contusions, subdural hematomas) and for traumatic axonal injury 1

Common Pitfalls to Avoid

• Do not delay CT imaging—brain imaging must occur immediately for any patient with loss of consciousness after head trauma 1, 2
• Do not rely on clinical examination alone to rule out intracranial injury when loss of consciousness has occurred 2
• Do not allow even brief periods of hypoxia or hypotension—these worsen secondary brain injury and significantly impact outcomes 1, 2, 3
• Do not use permissive hypotension in traumatic brain injury except in exceptional circumstances after escalation to trauma network 1
• Do not assume patients with mild head injury can be safely observed at home—loss of consciousness requires hospital evaluation 2
• Do not hyperventilate routinely—this causes cerebral vasoconstriction and ischemia; reserve for impending herniation only 1

Potential Complications Requiring Vigilance

• Secondary brain insults (hypoxia, hypotension, hyperthermia) 4, 5
• Intracranial hemorrhage expansion 4
• Cerebral edema and herniation 4, 5
• Post-traumatic seizures 2, 4
• Pulmonary complications (aspiration, ARDS) 4
• Infectious complications 4
• Venous thromboembolism 6
• Gastrointestinal complications 4