The implications of cerebral ischemia and metabolic dysfunction for treatment strategies in neurointensive care

Abstract

This review outlines recent observations made in a clinical setting that document the extent and degree of cerebral ischemia and metabolic dysfunction after acute brain injury. The intent is to guide clinicians in considering how best to monitor and treat brain metabolism in the intensive care unit. Recent findings have documented that following brain injury there is a heterogeneous distribution of disturbed metabolism with some areas of the brain rendered severely oligemic or ischemic while other areas are less affected. Areas that are not truly ischemic, however, still appear to be at risk of excitotoxic injury. Various methods of monitoring the brain are compared and discussed, including positron emission tomography, brain parenchymal oxygenation monitoring, brain microdialysis, and continuous electroencephalography; important caveats are also presented. These methods are complementary and provide information about oxygen utilization and other aspects of brain metabolism. Integration of these methods into a practical clinical protocol is discussed. The intensive care of acute brain injury has entered a new era in which monitoring of brain metabolism will permit targeted therapy and may possibly minimize iatrogenic adverse effects by making better use of our powerful therapies.