NEW ADVANCES IN CEREBRAL MONITORING

Abstract

SUMMARY T o study the recent techniques of cerebral monitoring we should study the detailed anatomy of brain which is divided to cerebral hemispheres, cerebellum, brainstem and dienceephalon brain is covered y 3 layers, the dura matter, the arachnoid matter and the pia matter. The brain receives 15-20% of cardiac output, the brain is mainly supplied by blood from circle of willies and drained by superficial and deep cerebral veins cerebral physiology is maintained y maintaining CPP and CBF without normal ranges by auto-regulation mechanisms. Monitoring of ICP has many indications like traumatic brain injuries, encephalitis, intracranial he, SAH. Methods of ICP monitoring includde EVD, camino, codman, pneumatic sensors, tympanic membrane eudiometry, ONSD and MRI. Normal ICP is 7-15 mm Hg adult. It is considered abnormal if exceeds 15 mm Hg. Modalities of CBF and CPP monitoring include TDF, LD flowmetry TCD, XE-CT, SPECT, CT-perfusion MR. Brain metabolism is monitored by cerebral micro dialysis which reveal several chemical substances (eg. glucose, lactate, pyruvate, Xanthine) which are markers of energy metabolic disturbance, tissue damage and inflammation. Ceberal oxygenation is monitored by SjvO2 NIRS, cerebral oximetry and brain tissue oxygen. Which revealed results that can be interpreted to predict outcomes after brain injuries. Brain tissue oxygen pressure measurement is increasingly being used for evaluation of cerebral oxygenation. It is used in patients with multiple extracranial injuries and TBI, aneurysmal subarachnoid hemorrhage, during aneurysm surgery, during surgery of cerebral arterio-venous malformations, during cerebral angiography, and during cardiopulmonary resuscitation. Two monitoring devices are currently available, "Licox" and "Neurotrend" technology. The Neurotrend probe uses optical sensors while The Licox probe uses a polarographic cell.