Cerebral Perfusion Pressure

To achieve adequate CPP, clinicians must balance (1) treating the underlying cause of elevated ICP and (2) appropriately supporting the patient’s blood pressure.

Low CPP (<60 mmHg):

• Patient is at risk for further neurological injury from cerebral hypoperfusion.
• Consider interventions to increase MAP (e.g. vasopressors, fluid bolus) or decrease ICP (e.g. elevate head of bed, mannitol, CSF drainage).

Normal CPP (60–70 mmHg)

• Patient likely has adequate cerebral perfusion.

High CPP (>70 mmHg)

• Patient is unlikely to benefit from CPP this high and may be at increased risk for hypoxemic respiratory failure and ARDS, which can contribute to cerebral ischemia and prolonged mechanical ventilation.
• If the patient has blood pressure room, consider backing down on interventions raising the patient’s MAP (e.g. pressors).

• Even if the patient has a normal calculated CPP, clinicians must also:
• Treat elevated ICP (current Brain Trauma Foundation guidelines recommend intervention for ICP >22 mmHg).
• Correct hypotension.
• Regional differences in ICP may exist (e.g. local mass effect can mean increased ICP in one particular area of the brain), leading to gradients in CPP across different areas of the brain. Interpret these results with caution.