[New trends in neuromonitoring patients with with aneurysmal subarachnoid haemorrhage]

Neurointensive care of patients with subarachnoid haemorrhage is based on the theory that clinical outcome is the consequence of the primary haemorrhage and a number of secondary insults in the acute post haemorrhage period. Several neuromonitoring techniques have been introduced or accomplished into clinical practice in the last decade with the purpose of monitoring different but related aspects of brain physiology, such as cerebral blood flow (CBF), pressure within the cranial cavity, metabolism, and oxygenation. The aim of these techniques is to obtain information that can improve knowledge on brain pathophysiology, and especially to detect secondary insults which may cause permanent neurological damage if undetected and untreated in "real time", at the time when they can still be managed. These techniques include intracranial pressure (ICP) measurements, jugular venous oxygen saturation, near-infrared spectroscopy, brain tissue monitoring, and transcranial Doppler. The available devices are limited because they measure a part of complex process indirectly. Expense, technical difficulties, invasiveness, limited spatial or temporal resolution and the lack of sensitivity add to the limitation of any individual monitor. These problems have been partially addressed by the combination of several monitors known as multimodality monitoring. In this review, we describe the most common neuromonitoring methods in patients with subarachnoidal hemorrhage that can assess nervous system function, cerebral haemodynamics and cerebral oxygenation.