Figure 1. Reduction in the propofol concentration that prevented movement to incision in 50% of patients by esmolol. Measured serum propofol concentration at incision versus esmolol infusion rate is plotted. Each point represents an individual patient who either moved ([circle, open]) or did not move ([circle, closed]) to skin incision. The line represents the 50% likelihood of movement to skin incision based on logistic regression analysis (Appendix 1).