Bispectral index monitoring in ischemic-hypoxic brain injury.

The BIS monitor is a simple-to-use and widely available monitor used in cardiac surgery. It can provide useful new information regarding the patient's hypnotic state, but also other components of brain function. The detection of cerebral hypoperfusion is of prime importance to perfusionists and others caring for patients undergoing cardiac surgery. BIS values consistent with the anesthetic drug and dose administration should reflect adequate cerebral perfusion and function. Abnormally low or a sudden deterioration in BIS values probably indicate cerebral hypoperfusion and should be taken seriously. A growing number of anecdotal reports and small case series support these contentions, but large prospective outcome studies are needed before this technology can be reliably used to monitor cerebral perfusion and other aspects of brain function during surgery.