What is the target blood pressure (BP) for head trauma patients?

Target Blood Pressure Management in Head Trauma

For patients with traumatic brain injury, the target systolic blood pressure should be maintained above 110 mmHg with a mean arterial pressure (MAP) above 90 mmHg, and kept below 150 mmHg if within 6 hours of symptom onset when immediate surgery is not planned 1.

Blood Pressure Targets by Type of Head Trauma

• For traumatic brain injury (including traumatic subarachnoid hemorrhage):

  • Systolic BP >110 mmHg and MAP >90 mmHg 1
  • Systolic BP <150 mmHg if within 6 hours of symptom onset and immediate surgery not planned 1

• For patients with combined hemorrhagic shock and severe traumatic brain injury:

  • Maintain MAP ≥80 mmHg 1

• For cerebral perfusion pressure (CPP) targets:

  • Maintain CPP between 60-70 mmHg in the absence of multi-modal monitoring 1
  • Higher CPP values (>90 mmHg) may worsen neurological outcomes by aggravating vasogenic cerebral edema 1

Management Considerations

Monitoring

• Use transduced direct arterial pressure monitoring with the transducer placed at the level of the tragus for accurate measurements 1
• If invasive monitoring is not immediately available, use NIBP measurements at 1-minute intervals during critical periods 1

Hypotension Management

• Hypotension (SBP <110 mmHg) in TBI patients is associated with significantly increased mortality 2, 3
• Have vasoconstrictors readily available (ephedrine, metaraminol) to treat immediate hypotension 1
• For resuscitation, use 0.9% saline as the preferred intravenous fluid 1
• Avoid hypotonic solutions such as Ringer's lactate in patients with severe head trauma 1

Hypertension Management

• For patients requiring BP reduction, labetalol is recommended as a vasoactive agent 1
• Avoid aggressive BP reduction that might compromise cerebral perfusion 1

Special Considerations

Intubation and Airway Management

• During intubation, prioritize maintaining target BP over concerns about cerebral stimulation 1
• For induction, consider:
  • High-dose fentanyl (3-5 μg/kg), alfentanil (10-20 μg/kg), or remifentanil TCI (≥3 ng/ml) 1, 4
  • Ketamine 1-2 mg/kg may be useful in hemodynamically unstable trauma patients 1
  • Use lower doses in unstable patients with multiple trauma 1

Intracranial Hypertension

• For threatened intracranial hypertension or signs of brain herniation:
  • Use mannitol 20% or hypertonic saline solution at a dose of 250 mOsm, infused over 15-20 minutes 1
  • Avoid prolonged hypocapnia as a treatment for intracranial hypertension 1
  • Maintain PaCO₂ between 4.5-5.0 kPa (brief periods of 4.0-4.5 kPa may be used if impending uncal herniation) 1

Pitfalls and Caveats

• Defining hypotension as SBP <90 mmHg in TBI patients is outdated; evidence suggests the threshold should be higher at 110 mmHg 2, 3
• Heterogeneity in perfusion requirements may exist both within the injured brain and at different times post-injury 5
• Patients with TBI and hypotension on hospital arrival have significantly worse outcomes, with mortality rates as high as 24% 3
• Avoid hyperoxia, especially in acute ischemic stroke, while maintaining adequate oxygenation (PaO₂ ≥13 kPa) 1, 4
• There is limited high-quality evidence supporting specific BP values; current recommendations are largely based on expert consensus 1