Monitoring in neuroanaesthesia: update of clinical usefulness

The aim of specific monitoring in neuroanaesthesia is to detect, as quickly as possible, intraoperative ischaemic insults so that the brain and the spinal cord may be protected from harmful and frequently inevitable events due to the type of surgery, patient positioning, haemodynamic changes or any intercurrent event. New monitors are being introduced into the operating theatre, but only a few are considered to be an absolute standard of care in neurosurgery, e.g. facial nerve monitoring for surgery of acoustic neuromas and recording of evoked potentials during repair of scoliosis. In the past decade, new monitoring devices have moved from the experimental stage to the operating theatre and although most are still in a phase of technological development and/or definition of their field of applicability they are being used as guides for clinical practice in those instances where cerebral well-being might be impaired. The metabolic consequences of hyperventilation, pharmacological electroencephalogram burst suppression, hypothermia, etc. can now be assessed in the operating theatre. Non-invasive monitoring is being rapidly integrated into our daily work because of its lack of secondary effects. Nevertheless, each new development is regarded as an addition rather than as a substitute for existing equipment. The perfect combination of monitors to provide essential information during an individual surgical procedure to influence a better patient outcome, is still uncertain and needs extensive clinical research.