title: The minimum alveolar concentration of desflurane in cats.
abstract: Eight adult cats, 4 male and 4 female, (3.5 +/- 0.9 [SD] kg) were used to determine the minimum alveolar concentration (MAC) of desflurane. Desflurane (DES) anesthesia was induced in a 20 L chamber with an oxygen inflow of 10 L/min and the DES vaporizer set at 18%. After 3.5 +/- 0.5 min, the cats were removed from the chamber and anesthesia was maintained via mask (14% DES, 3L/min O2) until successful intubation. Anesthesia was maintained with DES in oxygen at a flow of at least 200 mL/kg/min through a nonrebreathing circuit. The time from the start of induction to completion of intubation was 6.2 +/- 1.1 min. Esophageal temperature was maintained between 37.8 degrees C and 38.6 degrees C. Hand-collected end-tidal gas samples were obtained from a catheter positioned inside the lumen of the endotracheal tube. Inspired and end-tidal DES concentrations were measured with a Biochem 8100 anesthetic agent monitor that was calibrated with known gas standards and modified to accept hand-collected samples. A constant alveolar concentration of DES was maintained for at least 15 minutes, then a clamp was applied to the tail and the cat observed for gross purposeful movement. The end-tidal DES was then increased (if a positive response) or decreased (if a negative response) by 20% and the test repeated after 15 minutes of constant conditions. The final iteration was 10%. The MAC of DES in these cats was 9.79 +/- 0.70 vol %. The FA/FI ratio for desflurane was always greater than 0.97.
authors.affiliation: Department of Clinical Sciences, Kansas State University, College of Veterinary Medicine, Manhattan, USA.
authors.forename: R M
authors.initials: RM
authors.lastname: McMurphy
authors.forename: D S
authors.initials: DS
authors.lastname: Hodgson
mesh_terms: D000769:Anesthesia, Inhalation / Q000662:veterinary*; D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000032:analysis* / Q000378:metabolism; D000818:Animals; D002415:Cats / Q000378:metabolism*; D000077335:Desflurane; D005260:Female; D007530:Isoflurane / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D008297:Male; D011650:Pulmonary Alveoli / Q000737:chemistry* / Q000378:metabolism
chemical_list: D018685:Anesthetics, Inhalation; D000077335:Desflurane; D007530:Isoflurane