What is the target blood pressure for adult trauma patients?

Target Blood Pressure in Adult Trauma Patients

Critical Distinction: With or Without Traumatic Brain Injury

The target blood pressure in adult trauma patients fundamentally depends on the presence or absence of traumatic brain injury (TBI), with TBI patients requiring significantly higher blood pressure targets to prevent secondary brain injury.

---

For Trauma WITHOUT Brain Injury

Target systolic blood pressure of 80-90 mmHg (or mean arterial pressure of 50-65 mmHg) until major bleeding is controlled. 1

Rationale for Permissive Hypotension

• Lower blood pressure targets reduce hydrostatic pressure on wounds, minimize dislodgement of blood clots, prevent dilutional coagulopathy, and avoid excessive fluid administration 1
• Multiply-injured trauma patients (ISS ≥16) with systolic blood pressure ≥60 mmHg who received low-volume resuscitation (0-1,500 ml) had higher survival rates than those receiving high-volume strategies (≥1,501 ml) 1
• A randomized trial comparing target MAP of 50 mmHg versus 65 mmHg in penetrating trauma showed that the lower target group had reduced 24-hour postoperative death and less coagulopathy, despite receiving less fluid and fewer blood products 1

Important Caveats

• Elderly patients and those with chronic hypertension: Permissive hypotension should be carefully considered or avoided, as these patients may not tolerate lower blood pressures 1
• Spinal cord injuries: Contraindicated due to need for adequate spinal cord perfusion 1

---

For Trauma WITH Traumatic Brain Injury

Maintain mean arterial pressure (MAP) ≥80 mmHg in patients with combined hemorrhagic shock and severe TBI (GCS ≤8). 1, 2

For isolated severe TBI without hemorrhagic shock, maintain systolic blood pressure >110 mmHg with MAP >90 mmHg. 2

Rationale for Higher Targets

• Adequate cerebral perfusion pressure is crucial to prevent secondary brain injury and ensure tissue oxygenation of the injured central nervous system 1
• Even brief episodes of hypotension (SBP <90 mmHg for ≥5 minutes) are associated with significantly increased neurological morbidity and mortality 2
• Impaired cerebral autoregulation after TBI makes the brain dependent on systemic MAP for adequate perfusion 2

Cerebral Perfusion Pressure Targets

• Target cerebral perfusion pressure (CPP) of 60-70 mmHg in the absence of multimodal monitoring 2, 3
• CPP is calculated as: MAP minus intracranial pressure 3
• Higher CPP values (>90 mmHg) may worsen neurological outcomes by aggravating vasogenic cerebral edema 2

Monitoring Recommendations

• Use transduced direct arterial pressure monitoring with the transducer placed at the level of the tragus for accurate measurements 2
• If invasive monitoring is not immediately available, use non-invasive blood pressure measurements at 1-minute intervals during critical periods 2

---

Fluid Resuscitation Strategy

Initial Fluid Choice

• Use crystalloids initially to treat hypotensive bleeding trauma patients 1
• Avoid hypotonic solutions (such as Ringer's lactate) in patients with severe head trauma, as they may worsen cerebral edema 1, 2
• Prefer 0.9% saline as the intravenous fluid for resuscitation in TBI patients 2

Volume Considerations

• Aggressive fluid resuscitation increases risk of coagulopathy: >40% with >2,000 ml, >50% with >3,000 ml, and >70% with >4,000 ml administered pre-clinically 1
• Pre-hospital IV fluid administration was associated with increased mortality (OR 1.11), particularly in penetrating trauma (OR 1.25), hypotension (OR 1.44), and severe head injury (OR 1.34) 1

---

Common Pitfalls to Avoid

• Do NOT apply permissive hypotension strategies to patients with TBI – this is the most critical error, as it dramatically worsens neurological outcomes 1, 2
• Do NOT rely solely on systolic blood pressure as a marker of shock – systolic blood pressure correlates poorly with base deficit (r=0.28) and remains normal until severe shock develops 4
• Do NOT assume normal blood pressure excludes ongoing internal bleeding – among patients with documented ongoing internal hemorrhage, 53% had systolic blood pressure ≥120 mmHg and only 15% had systolic blood pressure <90 mmHg 5
• Avoid excessive fluid administration – early large-volume crystalloid administration is the greatest predictor of secondary abdominal compartment syndrome 1

---

Age-Specific Considerations

Hemodynamic Stability Definitions (Adult)

• Hemodynamically unstable: Admission systolic blood pressure <90 mmHg with evidence of skin vasoconstriction (cool, clammy skin, decreased capillary refill), altered consciousness, and/or shortness of breath 1
• Alternative unstable criteria: Systolic blood pressure >90 mmHg but requiring bolus infusions/transfusions and/or vasopressor drugs, and/or base excess >-5 mmol/L, and/or shock index >1, and/or transfusion requirement of 4-6 units of packed red blood cells within 24 hours 1