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    Cerebral Perfusion Pressure

    Calculates blood flow to the brain.
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    INSTRUCTIONS

    Use in patients with an intracranial pressure monitoring device.

    When to Use
    Pearls/Pitfalls
    Why Use

    Use in supine patients with elevated intracranial pressure (e.g. from hemorrhage, edema, mass).

    • Requires invasive intracranial pressure (ICP) monitoring.
    • Although there is still some debate in the literature, it is generally accepted that the normal range of CPP in a supine patient is 60–70 mmHg.
    • Clinicians must address both the patient’s CPP and ICP. For example, a patient could have a normal calculated CPP, but if the ICP is significantly elevated, it must be treated.
    • The definition of normal ICP changes with posture and age. It also varies slightly depending on which data are applied. Therefore, it is important to be aware of local practice guidelines when applying this calculator.
    • CPP decreases as ICP rises, leading to cerebral ischemia and further neurological injury.
    • Calculating CPP helps clinicians identify patients who may be experiencing ongoing neurological injury from inadequate cerebral perfusion.
    • Helps prevent further cerebral ischemia by treating elevated ICP and hypotension as appropriate.
    mm Hg
    mm Hg

    Result:

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    Next Steps
    Evidence
    Creator Insights

    Advice

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

    Management

    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).

    Critical Actions

    • Even if the patient has a normal calculated CPP, clinicians must also:
    • 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.
    Content Contributors
    • Lubabah Ben-Ghaly, MD
    Reviewed By
    • Jarone Lee, MD
    About the Creator
    Dr. Luzius A. Steiner
    Are you Dr. Luzius A. Steiner?
    Content Contributors
    • Lubabah Ben-Ghaly, MD
    Reviewed By
    • Jarone Lee, MD