From the Guidelines
The recommended Mean Arterial Pressure (MAP) goal in patients with diffuse zonal traumatic injury is typically 80-90 mmHg, as supported by the most recent evidence from the European guideline on management of major bleeding and coagulopathy following trauma: sixth edition 1.
Rationale
The concept of permissive hypotension and restrictive volume resuscitation is supported by several meta-analyses of retrospective studies, as well as combined prospective and retrospective studies, showing reduced mortality in comparison to traditional aggressive volume replacement targeting normotension 1. However, this concept is contraindicated in patients with TBI and spinal injuries, as an adequate perfusion pressure is crucial to ensure tissue oxygenation of the injured central nervous system.
Key Considerations
- The use of a damage control resuscitation strategy with a concept of restricted fluid replacement aiming to achieve a reduced systolic blood pressure of 80–90 mmHg in patients without TBI and/or spinal injury is supported by the literature 1.
- Rapid bleeding control is of particular importance in these patients, and the concept of permissive hypotension should be carefully considered in elderly patients and may be contraindicated if the patient suffers from chronic arterial hypertension 1.
- The physiological basis for this higher MAP target is to overcome potential compression-induced ischemia and to counteract impaired autoregulation in the injured neural tissue, thereby minimizing secondary injury from hypoperfusion 1.
Management
Achieving the recommended MAP goal often requires a combination of intravenous fluids and vasopressors, such as norepinephrine or phenylephrine, titrated to effect. Continuous arterial line monitoring is essential for accurate MAP measurement.
- Norepinephrine can be started at 0.05-0.1 mcg/kg/min and titrated to effect, while phenylephrine can be started at 0.5-1 mcg/kg/min and titrated to effect.
- The use of dynamic measures, such as pulse pressure variation, to predict fluid responsiveness in patients with sepsis or septic shock can help guide fluid management 1.
From the Research
Mean Arterial Pressure Goal in Diffuse Zonal Traumatic Injury
- The recommended Mean Arterial Pressure (MAP) goal in patients with diffuse zonal traumatic injury is not explicitly stated in the provided studies.
- However, according to 2, a target systolic arterial pressure of 80-90 mmHg is recommended until the control of hemorrhage in trauma patients without brain injury.
- In patients with traumatic brain injury, a mean arterial pressure target of > 60 mmHg is recommended 3, 4.
- A meta-analysis of randomized controlled trials found that a higher MAP goal of > 70 mmHg was associated with similar outcomes compared to a standard MAP goal of 60-70 mmHg in critically ill patients 5.
- The use of vasopressors, such as arginine vasopressin, may be beneficial in achieving MAP goals in trauma patients with hemorrhagic shock or neurogenic shock 3, 6, 4.
- It is essential to note that the optimal MAP goal may vary depending on the individual patient's condition, such as the presence of brain injury or spinal cord injury, and should be determined on a case-by-case basis.