The introduction of bispectral index (BIS) in anesthesia practice

Abstract

During every surgical procedure we must keep the anesthetic level at an appropriate level so that the patient will neither feel pain nor remember the operation. Yet this anesthetic depth must be balanced against the negative effects and consequences of excess anesthetic and the associated potential for delayed wake up. A wide range of monitoring devices allows us to to avoid the risks of pain, unwanted movements, hemodynamic changes as well as awareness. During the past few years processed EEG signals have become available that help gauge the depth of anesthesia by generating a score linked to EEG activity, which becomes depressed as anesthesia deepens. The bispectral index (BIS) represents one of these innovative methods of monitoring in anesthesia, even if more studies are still needed to make it more precise, especially in pediatric patients and neonates where reliability has yet to be well established.