A closer look at bispectral index monitoring

The most common fear expressed by preanesthesia patients is experiencing awareness while under general anesthesia. Although extremely rare, awareness during anesthesia does occur and patients have recalled explicit details and conversations that occurred while they were under general anesthesia, including described recall of the intubation process. The Bispectral Index Monitor (BIS) was developed by Aspect Medical System of Newton, MA, to measure patient response to the administration of potent sedative, hypnotic agents. The BIS monitor is intended to decrease the risk of intraoperative awareness by providing the anesthetist with a quantitative assessment regarding the hypnotic state of the patient.