The anesthetic requirements for sevoflurane, isoflurane, and halothane were determined in mongrel dogs. The MACs (minimum alveolar concentration) of sevoflurane, isoflurane, and halothane were 2.36 +/- 0.46% (n = 18), 1.39 +/- 0.25% (n = 10), and 0.89 +/- 0.20% (n = 2), respectively (mean +/- SD). In agreement with sevoflurane's low blood/gas partition coefficient (0.6), the rate of rise of alveolar concentration toward that inspired (FA/F1) for sevoflurane was significantly faster than that for either halothane or isoflurane. Thirty seconds after breathing a constant inspired concentration FA/F1 was 0.75 for sevoflurane, which was 2.96 times higher than that with halothane (0.25 +/- 0.02) and 1.29 times higher than that with isoflurane (0.6 +/- 0.05). Induction with sevoflurane was smooth, with no struggling nor excessive salivation.
(C) 1988 American Society of Anesthesiologists, Inc.