Minimum alveolar concentration of sevoflurane in spontaneously breathing llamas and alpacas

J Am Vet Med Assoc. 2003 Oct 15;223(8):1167-9. doi: 10.2460/javma.2003.223.1167.


Objective: To determine the minimum alveolar concentration (MAC) of sevoflurane in spontaneously breathing llamas and alpacas.

Design: Prospective study.

Animals: 6 healthy adult llamas and 6 healthy adult alpacas.

Procedure: Anesthesia was induced with sevoflurane delivered with oxygen through a mask. An endotracheal tube was inserted, and a port for continuous measurement of end-tidal and inspired sevoflurane concentrations was placed between the endotracheal tube and the breathing circuit. After equilibration at an end-tidal-to-inspired sevoflurane concentration ratio > 0.90 for 15 minutes, a 50-Hz, 80-mA electrical stimulus was applied to the antebrachium until a response was obtained (ie, gross purposeful movement) or for up to 1 minute. The vaporizer setting was increased or decreased to effect a 10 to 20% change in end-tidal sevoflurane concentration, and equilibration and stimulus were repeated. The MAC was defined as the mean of the lowest end-tidal sevoflurane concentration that prevented a positive response and the highest concentration that allowed a positive response.

Results: Mean +/- SD MAC of sevoflurane was 2.29 +/- 0.14% in llamas and 2.33 +/- 0.09% in alpacas.

Conclusions and clinical relevance: The MAC of sevoflurane in llamas and alpacas was similar to that reported for other species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anesthetics, Inhalation / administration & dosage
  • Anesthetics, Inhalation / standards*
  • Animals
  • Camelids, New World / metabolism*
  • Female
  • Intubation, Intratracheal / veterinary
  • Male
  • Methyl Ethers / administration & dosage
  • Methyl Ethers / standards*
  • Prospective Studies
  • Respiration / drug effects
  • Sevoflurane


  • Anesthetics, Inhalation
  • Methyl Ethers
  • Sevoflurane