Cerebral Perfusion Pressure
CPP reflects the pressure gradient driving cerebral blood flow. Input intracranial pressure and either mean arterial pressure or systolic/ diastolic values to derive MAP automatically.
From ventriculostomy, intraparenchymal monitor, or lumbar transducer.
How to Use This Calculator
Acquire reliable ICP measurement
CPP calculations depend on accurate intracranial pressure obtained from ventriculostomy or parenchymal monitors. Calibrate frequently.
Determine mean arterial pressure
Use invasive arterial line MAP or calculate from cuff systolic and diastolic values: MAP = (SBP + 2×DBP)/3.
Integrate with clinical management
CPP targets (60–70 mmHg) must be balanced with risks of hypertension. Combine with autoregulation indices, sedation, and osmotherapy to optimize cerebral perfusion.
Formula
CPP = MAP − ICP
MAP (cuff) = (Systolic + 2 × Diastolic) ÷ 3
Typical CPP target for adult traumatic brain injury: 60–70 mmHg (Brain Trauma Foundation guidance).
Full Description
Cerebral perfusion pressure approximates cerebral blood flow when autoregulation is impaired. Maintaining CPP above ischemic thresholds while avoiding excessive hypertension is essential in neurocritical care (traumatic brain injury, subarachnoid hemorrhage, intracranial hemorrhage). Management combines sedation, osmotic therapy, CSF drainage, vasopressors, and individualized CPP targets guided by multimodal monitoring.
Factors such as brain compliance, autoregulation status, and regional perfusion also impact outcomes. Monitor CPP trends alongside cerebral oxygenation, microdialysis, and neurological examination for tailored therapy.
Frequently Asked Questions
What if autoregulation is intact?
Patients with intact autoregulation may tolerate lower CPP. Some centers use pressure reactivity index (PRx) to tailor individualized CPP targets.
How quickly should CPP be adjusted?
Respond promptly to sustained CPP < 60 mmHg, evaluating MAP and ICP contributors. Address systemic hypotension, sedation depth, ventilator settings, and CSF drainage.
Do pediatric CPP targets differ?
Yes. Pediatric CPP goals depend on age, typically 40–60 mmHg. Consult pediatric neurocritical care guidelines for age-specific thresholds.
What if BP is measured invasively?
Use invasive MAP directly (no conversion required). Confirm arterial transducer is leveled at the tragus when managing CPP to reflect cerebral perfusion more accurately.