Cost-effectiveness of bispectral index monitoring

In the current era of limited resources, organizations are evaluating the cost-effectiveness of their care. To analyze the cost-effectiveness of a physiologic monitor, one must first determine what negative outcome will be reduced or what positive outcome will be promoted. For example, if one was studying the cost-effectiveness of the pulse oximeter, it would be important to state whether the endpoint is prevention of hypoxic events or prevention of myocardial infarction. One would then need outcome data demonstrating the incidence of the chosen endpoint with and without the monitor. With these data, one can begin to construct a model for cost-effectiveness. Like many medical technologies, the bispectral index (BIS) monitor has recently been the subject of several articles which study its cost-effectiveness. This review examines the rationale of cost-effectiveness analyses and their application specifically to the BIS monitor.

The BIS monitor has been shown in multiple prospective randomized studies to positively affect several important aspects of an anesthetic. Use of the BIS monitor results in less use of hypnotic anesthetic drugs, decreased time to extubation, decreased incidence of nausea and vomiting, and decreased intraoperative awareness. These benefits are achieved for an additional cost of around five dollars per anesthetic. In addition, there is an emerging body of literature demonstrating an association between low intraoperative BIS readings and decreasing intermediate-term survival in both noncardiac and cardiac surgical patients.

Given the trivial cost of the BIS and the proven benefits demonstrated in prospective randomized studies, we consider its use justified in every general anesthetic.