Figure 1. The end-tidal sevoflurane concentration for consecutive subjects in each group is displayed. The solid line indicates the 0.7 MAC Xe group, the broken line the N2O group, and the dotted line the 1 MAC Xe group. The determination of MAC-BAR is defined in the text. The MAC-BAR values of each group are represented by horizontal lines. The vertical axis MAC values include the contribution of Xe or N2O.