Fig. 1.
Relation between propofol-predicted effect site concentration and bispectral index (BIS) effect. Each panel shows a different individual. Dotted blue line corresponds to propofol, red to remifentanil, and black continuous tracing represents the BIS. A delay between BIS and propofol-predicted effect site concentration can be clearly observed in the two subjects, suggesting inadequacy of the ke0 used to estimate predicted effect site concentrations.