Hemodynamics

Cerebral Perfusion Pressure (CPP) Calculator

MAP minus ICP, the pressure that drives blood through the brain; the number to protect after traumatic brain injury.

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · From the Reference tab of the app

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Formula

CPP = MAP - ICP

Reference: TBI target 60–70 mm Hg

How it is used

• Goal CPP in traumatic brain injury (TBI) is 60–70 mm Hg (Brain Trauma Foundation).
• Low CPP causes ischemia; avoid pushing CPP above 70 with fluids and vasopressors, which raised the risk of ARDS.
• Intact autoregulation holds cerebral flow steady across a CPP of roughly 50–150 mm Hg; after TBI, SAH or ICH it often fails and flow follows pressure.

Key points

• Treat elevated ICP with hyperosmolar therapy (mannitol, hypertonic saline), sedation, or CSF drainage before aggressively pushing MAP with vasopressors.

Same formula as the app. Open it in the web app.

Related one-pagers

• Neuro: ICP and StrokeCPP · MAP − ICP
• ACLS Algorithms in BriefCPP is aortic minus right atrial diastolic pressure; no patient reached ROSC below 15 mm Hg (Paradis 1990).
• Pediatric Assessment and EmergenciesPECARN (Kuppermann 2009) for minor head trauma under age 2: GCS 14, other altered mentation or a palpable skull fracture means CT (4.4% risk of important brain injury); a nonfrontal scalp hematoma, loss of consciousness of 5 seconds or more, a severe mechanism or not acting normally allows observation or CT (0.9%); none of these means no CT (under 0.02%). In severe TBI the Brain Trauma Foundation (2019) treats ICP over 20 mm Hg, keeps CPP at least 40, gives 3% saline 2–5 mL/kg and avoids PaCO₂ below 30 in the first 48 hours.
• After Cardiac SurgeryAir embolism. Arterial air, as after incomplete de-airing of an open chamber, is treated with 100% oxygen to shrink the bubbles, with the patient kept flat supine because head-down positioning may worsen cerebral edema, and hyperbaric oxygen is considered for neurologic deficits (McCarthy 2016). Coronary air favors the RCA, which arises from the anterior coronary sinus where bubbles are most likely to travel, giving inferior ST elevation, heart block and hypotension; raising perfusion pressure pushes the air through (Nezafati 2024). Venous air through an open central line: stop the entry, place the patient left side down in Trendelenburg (Durant), give 100% oxygen and aspirate air from the right heart through a central catheter (Gordy 2013).

Related calculators

• Cardiac Index (CI)
• Cardiac Output (Fick Principle)
• Cardiac Output (HR × SV)
• Coronary Perfusion Pressure
• Ejection Fraction (EF)
• Mean Arterial Pressure (MAP)
• Oxygen Delivery (DO₂)
• Pulmonary Vascular Resistance (PVR)

For education and exam preparation only. Follow your institution’s protocols. For education and exam preparation only. Verify results independently and follow your institution’s protocols. Not a substitute for clinical judgment.