The patient who is in depression, either in the operating room or in the intensive care unit, can not be examined neurologically and so an intracranial complication can develop without it being noticed by the doctors. However, if physical parameters such as intracranial pressure, oxygen, carbon dioxide, temperature and metabolism of brain tissue are monitored, then a complication can be diagnosed early and often treated with appropriate treatment (medication or decompression surgery in the brain). Neuromonitoring, i.e. the continuous recording of these parameters, has saved the lives of many patients, who would otherwise either die or suffer serious and permanent neurological damage.