The validity of bispectral index values from a dislocated sensor: a comparison with values from a sensor located in the commercially recommended position.

Abstract

The influence of sensor dislocation on bispectral index (BIS) values is not clear. We compared the BIS values obtained from dislocated sensors with those from the commercially recommended positions. We used two BIS sensors for each patient receiving propofol-based anesthesia; one in the recommended position and one positioned around the lateral corner of the right eye. Bland and Altman analysis revealed better agreement of two BIS values when the values during induction of and emergence from anesthesia were excluded. The results indicate that during induction of and emergence from general anesthesia, a dislocated BIS sensor may produce questionable BIS values.