Cerebral perfusion pressure (CPP) plays a central role in neurointensive care and is crucial for maintaining adequate cerebral blood flow.
Definition
CPP is defined as the difference between mean arterial pressure (MAP) and intracranial pressure (ICP):
CPP = MAP – ICP
This relationship shows that CPP is influenced by both MAP and ICP.
Normal Values
The normal CPP value in adults is above 50 mmHg[^2].
Optimization of CPP
Various approaches can be taken to optimize CPP:
Increase MAP: This can be achieved through fluid administration or medications that increase blood pressure. An increase in MAP leads to an increased CPP, provided that ICP remains constant.
Decrease ICP: A reduction in intracranial pressure can be achieved pharmacologically, such as through sedation or Mannitol or by surgical interventions such as decompressive hemicraniectomy. Lowering ICP has a positive effect on CPP by increasing the difference to MAP.
Clinical Relevance in Trauma
In patients with traumatic brain injury, it has been shown that patients benefit more from a reduction in ICP than an increase in MAP to maintain cerebral perfusion[^1].