Monitoring of Brain Function in Neurointensive Care: Current State and Future Requirements

Abstract

Although the human brain comprises only 2% of the body weight, it receives 15–20% of the cardiac output and accounts for 20% of the total body oxygen consumption. Since the brain has almost no energy reserves, adequate cerebral blood flow is essential to prevent brain damage. Under normal circumstances the brain has an intrinsic ability to regulate its blood supply. This cerebral autoregulation may be impaired after traumatic brain injury or other cerebral insults (e.g. subarachnoid haemorrhage). For the treating neurointensivist, it is one of the main therapeutic needs to maintain adequate cerebral perfusion in these patients to prevent secondary brain insults, which ultimately result in further cerebral damages. Up to now, there are only few monitoring tools available to achieve this goal. All of them have limitations (e.g. focal methods with a sampling error, exposure to radiation, no 24 h availability, high staff resources, high costs). This chapter will give an overview about the current monitoring strategies and the requirements new techniques have to fulfil.