Neuromonitoring: brain oxygenation and microdialysis.

Patients with cerebral lesions run a high risk of developing cerebral hypoxic and ischemic damage due to secondary insults. To minimize the risk of secondary cerebral hypoxia and ischemia, new monitoring techniques of cerebral oxygenation and metabolism have been developed and may help to understand the pathophysiology of secondary brain damage for a better treatment and outcome in critical patients. Cerebral microdialysis is a relatively new technique for measuring brain molecules of the extracellular space. The technical aspects, the interpretation of the commonly measured parameters, the use of the two commonly used oxygenation parameters (jugular venous oxygen saturation and monitoring of brain tissue PO(2) and the microdialysis technique to monitor cerebral metabolism in patients with head injury), subarachnoid hemorrhage, and ischemic stroke are considered. Pitfalls of the techniques and their future potential are discussed.