Fig. 1. End-tidal and inspired concentrations of sevoflurane (  A ) and halothane (  B ) during simulated inhalational induction. In each panel, the  upper set of data points represent inspired concentrations, and the  lower set of data points represent end-tidal concentrations. Inspired anesthetic concentration was increased by approximately 0.05 minimal alveolar concentration (MAC) every three breaths. The greater number of breaths in the halothane protocol was required to reach an equivalent end-tidal MAC by the end of induction. Data points represent mean ± SD of sixteen experiments in eight participants.