Multimodal monitoring in the neurological intensive care unit.

BACKGROUND: Neurocritical care is a specialty that focuses on the critical care management of patients with catastrophic neurologic diseases. Brain ischemia and hypoxia are often central causes of brain damage in these patients. Until recently, the only methods widely accepted for monitoring in the neurological intensive care unit have been intracranial pressure and cerebral perfusion pressure monitoring. Recent developments in technology have resulted in several new monitoring techniques that can provide the neurointensivist with information, at the cellular level, that can help guide management. REVIEW
SUMMARY: The brain requires a continuous blood-borne supply of oxygen and glucose for normal metabolism. Ischemia occurs when supply is insufficient to meet the metabolic demand. Cerebral blood flow can now be directly monitored using laser Doppler or thermal diffusion techniques. Transcranial cerebral oximetry can estimate regional cerebral oxygen saturation, although the reliability is questionable. Jugular bulb oximetry can provide a global assessment of oxygen delivery, and consumption and brain tissue oxygen tension monitoring can provide a focal measurement of cerebral oxygenation. Intracerebral microdialysis can provide information about glucose metabolism and the overall health of the neuron.
CONCLUSIONS: New monitoring techniques can provide the neurointensivist with crucial information about brain physiology and metabolism. Combining these techniques ("multimodal monitoring") can produce a more accurate overall picture. This approach, along with new computer systems for integrating data at the bedside, may change the way patients with brain injury are monitored and treated in the future.