A patient with ICP monitoring has pressure of 12 mm Hg. The nurse understands this pressure reflects

• A. A severe decrease in cerebral perfusion pressure
• B. An alteration in the production of CSF
• C. The loss of autoregulatory control of ICP
• D. A normal balance between brain tissue, blood, and CSF

Answer: (D)

Intracranial pressure reflects the combined volume of brain tissue, blood, and CSF inside the skull. A measurement of 12 mm Hg falls within the normal range (roughly 0–15 mm Hg in adults), indicating that these components are in balance and not causing elevated pressure.

This value alone doesn’t determine cerebral perfusion pressure (CPP) because CPP = MAP − ICP; you’d need the mean arterial pressure to judge CPP. It also doesn’t alone indicate changes in CSF production or autoregulation of cerebral blood flow. So the pressure represents a normal balance among brain tissue, blood, and CSF.