Systemic and Intracranial Mechanisms of Brain Ischaemia: Monitoring the Threat

Abstract

Brain ischaemia is found in 88%–92% of brains at post-mortem. About 33% of such brains show medial-occipital necrosis, and boundary zone ischaemia between middle and anterior territories occurs in 22% of patients. Global ischaemia due to raised intracranial pressure (ICP) was shown by Douglas Miller to occur in 10%–15% of adults during intensive care; if this global ischaemia is associated for long periods with a low cerebral perfusion pressure (CPP) (under 50 mm Hg), the mortality rate is as high as 90%. The Lund group are advocating CPP management below 50 mm Hg, but this is a different scenario from a CPP of 50 plus a very low ICP.