Figure 1. Consecutive measurements of neurocirculatory variables (mean plus/minus SEM) during induction of anesthesia with propofol and the subsequent mask administration of sevoflurane or desflurane for a 10-min period. The inspired concentration of these anesthetics was increased at 1-min intervals beginning precisely 2 min after propofol administration (0.41 MAC of sevoflurane 1% and of desflurane 3.65%). The average end-tidal concentrations (Exp) recorded and averaged over each minute of anesthetic administration are depicted above the mean arterial pressure (MAP) tracing. In both groups, propofol reduced sympathetic nerve activity (SNA) and MAP and increased heart rate (HR). The subsequent administration of sevoflurane did not alter HR or SNA but led to a progressive decline in MAP. In contrast, desflurane resulted in significant increases in neurocirculatory variables that persisted throughout the 10-min mask administration period. The end-tidal anesthetic concentrations during the 10th minute of mask administration revealed that desflurane had achieved a higher relative minimum alveolar concentration than had sevoflurane. *Significant difference between groups at specific times; P < 0.05. dagger Significant interaction between groups over time (analysis of variance); P < 0.05.