Confusion with cerebral perfusion pressure in a literature review of current guidelines and survey of clinical practise

Abstract
Cerebral perfusion pressure (CPP) is defined as the difference between the mean arterial pressure (MAP) and the intracranial pressure (ICP). However, since patients with traumatic brain injury (TBI) are usually treated with head elevation, the recorded CPP values depends on the zero level used for calibration of the arterial blood pressure. Although international guidelines suggest that target values of optimal CPP are within the range of 50 – 70 mmHg in patients with TBI, the calibration of blood pressure, which directly influences CPP, is not described in the guidelines.