Microdialysis in traumatic brain injury--methodology and pathophysiology.

The application of clinical microdialysis to monitor changes in cerebral extracellular chemistry is now well established in several neurosurgical units worldwide. In neuro-intensive care the technique has been predominantly applied to patients with traumatic brain injury and subarachnoid haemorrhage. There is no doubt that microdialysis has increased and continues to increase our understanding of the pathophysiology of these conditions. Current studies are addressing the potential role of microdialysis as a clinical monitoring technique assisting in the management of patients on an intention to treat basis. This involves establishing the relationship between microdialysis and outcome, and the effect of therapeutic manoeuvres on the chemistry. This manuscript describes the place of microdialysis in traumatic brain injury in terms of the fundamental principles, methodology, pathophysiology and clinical application.