What are the recommended steps for the emergency assessment and initial management of a suspected acute brain injury?

Emergency Assessment and Initial Management of Acute Brain Injury

Immediate Priorities: The ABC-Plus-Hemorrhage Algorithm

In patients with suspected acute brain injury, immediately control life-threatening hemorrhage first, then secure airway/breathing/circulation, followed by urgent neurological evaluation and brain CT—all while aggressively preventing hypotension and hypoxia, which are the most modifiable determinants of mortality and neurological outcome. 1, 2

Step 1: Control Active Exsanguination (If Present)

• All patients with life-threatening hemorrhage require immediate surgical or interventional radiology intervention for bleeding control before addressing brain injury. 1, 3
• This takes absolute priority—even over neurosurgical intervention for brain lesions. 1

Step 2: Airway and Ventilation Management

• Immediately intubate and mechanically ventilate all severe TBI patients (Glasgow Coma Scale ≤8), beginning in the prehospital period. 2, 3
• Maintain PaCO₂ between 35-40 mmHg to prevent cerebral vasoconstriction and secondary ischemia. 1, 2, 3
• Maintain PaO₂ between 60-100 mmHg—hypoxemia occurs in 20% of TBI patients and dramatically worsens outcomes, with 75% mortality when combined with hypotension. 1, 3
• Use end-tidal CO₂ monitoring continuously. 3

Step 3: Hemodynamic Resuscitation

• Maintain systolic blood pressure >110 mmHg from the moment of first contact—even a single episode of SBP <90 mmHg for ≥5 minutes significantly increases morbidity and mortality. 1, 2, 3
• Alternative target: Mean arterial pressure >80 mmHg. 1, 3
• Start vasopressors (phenylephrine or norepinephrine) immediately for hypotension—never delay while waiting for "adequate fluid resuscitation." 2
• In cases of difficult intraoperative bleeding control, lower blood pressure values may be tolerated for the shortest possible time. 1

Step 4: Urgent Neurological Evaluation

• After hemorrhage control (or if no life-threatening bleeding), perform urgent neurological assessment including:
  • Pupillary examination 1, 4, 3
  • Glasgow Coma Scale motor score (if feasible) 1, 3
  • Full GCS when possible 1

Step 5: Immediate Brain Imaging

• Obtain non-contrast CT of brain and cervical spine immediately without any delay. 1, 2
• CT indications by severity:
  • Severe TBI (GCS ≤8): Always, immediately 1
  • Moderate TBI (GCS 9-13): Always, immediately 1
  • Mild TBI (GCS 14-15): If any of the following present: 1
    • Basilar skull fracture signs (rhinorrhea, otorrhea, hemotympanum, Battle's sign, raccoon eyes)
    • Displaced skull fracture
    • Post-traumatic seizure
    • Focal neurological deficit
    • Coagulation disorders or anticoagulant therapy

Step 6: Neurosurgical Consultation and Intervention

• After hemorrhage control, all salvageable patients with life-threatening brain lesions require urgent neurosurgical consultation and intervention. 1, 4, 3
• Surgical evacuation criteria: 2
  • Symptomatic extradural hematoma
  • Acute subdural hematoma with thickness >5mm and midline shift >5mm
  • Brain contusions with mass effect
  • Acute hydrocephalus requiring drainage
  • Open displaced skull fracture
  • Closed displaced skull fracture with brain compression

Step 7: Intracranial Pressure Monitoring

• Place ICP monitor in comatose patients at risk for intracranial hypertension (radiological signs of IH), regardless of need for emergency extra-cranial surgery. 1, 2, 3
• Target cerebral perfusion pressure ≥60 mmHg once ICP monitoring available. 2, 3

Critical Physiologic Targets During Initial Management

Blood Product Thresholds

• Transfuse red blood cells for hemoglobin <7 g/dL during interventions for life-threatening hemorrhage or emergency neurosurgery. 1, 2, 3
• Higher transfusion threshold for elderly patients or those with limited cardiovascular reserve. 1, 2
• Maintain platelet count >50,000/mm³ for systemic hemorrhage; >100,000/mm³ for emergency neurosurgery including ICP probe insertion. 1, 2, 3
• Maintain PT/aPTT <1.5× normal control. 3

Ventilation Strategy

• Consider increasing PEEP from 0 to 5-15 cm H₂O, which decreases ICP and improves cerebral perfusion pressure. 2
• In cerebral herniation (awaiting or during emergency neurosurgery), use osmotherapy and/or temporary hypocapnia. 1
• Outside of herniation, avoid hyperventilation—it worsens outcomes. 1, 3

Sedation Management

• Use propofol by continuous infusion (never bolus) combined with normocapnia to decrease ICP. 2
• Avoid hypotensive sedative agents and bolus sedation. 2

Monitoring and Reassessment

Neurological Monitoring Frequency

• Moderate TBI (GCS 9-13): 1
  • Every 15 minutes for first 2 hours
  • Then every hour for following 12 hours
• Any decrease of ≥2 points in GCS or new neurological deficit mandates repeat CT scan immediately. 1

Adjunctive Monitoring

• Consider transcranial Doppler on admission to assess cerebral perfusion and predict secondary deterioration: 1
  • Diastolic velocity <20-25 cm/s suggests poor outcome
  • Pulsatility index >1.25-1.4 predicts secondary neurological degradation
  • Mean velocity <28 cm/s associated with higher mortality

Common Pitfalls to Avoid

• Never allow even brief episodes of hypotension while waiting for "adequate resuscitation" before starting vasopressors—this is the single most preventable cause of secondary brain injury. 2
• Never delay transfer to a specialized neurosurgical center for "stabilization" at a non-neurosurgical facility—time to definitive care determines outcome. 2
• Never use bolus sedation instead of continuous infusions—bolus administration causes ICP spikes. 2
• Never delay intubation in patients with GCS ≤8—this is a clear indication for airway protection. 4
• Never hyperventilate routinely—reserve only for acute herniation while awaiting neurosurgery. 1

Special Considerations for Polytrauma

• In patients requiring both hemorrhage control and neurosurgical intervention, develop protocols for simultaneous multisystem surgery when feasible after initial hemorrhage control. 3
• EMS should bypass hospitals without stroke/trauma resources and transport directly to the closest facility capable of treating acute brain injury. 1