title: Validation of the bispectral index as an indicator of anesthetic depth in Thoroughbred horses anesthetized with sevoflurane.
abstract: To evaluate the bispectral index (BIS) as an indicator of anesthetic depth in Thoroughbred horses, BIS values were measured at multiple stages of sevoflurane anesthesia in five horses anesthetized with guaifenesin and thiopental following premedication with xylazine. There was no significant difference between the BIS values recorded at end-tidal sevoflurane concentrations of 2.8% (median 60 ranging from 47 to 68) and 3.5% (median 71 ranging from 49 to 82) in anesthetized horses. These BIS values during anesthesia were significantly lower (P<0.01) than those in awake horses (median 98 ranging from 98 to 98) or sedated horses (median 92 ranging from 80 to 93). During the recovery phase, the BIS values gradually increased over time but did not significantly increase until the horses showed movement. In conclusion, the BIS value could be useful as an indicator of awakening during the recovery period in horses, as previous reported.
authors.affiliation: Racehorse Clinic, Miho Training Center, Japan Racing Association, Ibaraki 300-0493, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Tokushige
authors.affiliation: Racehorse Clinic, Miho Training Center, Japan Racing Association, Ibaraki 300-0493, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Kakizaki
authors.affiliation: Racehorse Clinic, Miho Training Center, Japan Racing Association, Ibaraki 300-0493, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Ode
authors.affiliation: Racehorse Clinic, Miho Training Center, Japan Racing Association, Ibaraki 300-0493, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Okano
authors.affiliation: Racehorse Clinic, Ritto Training Center, Japan Racing Association, Shiga 520-3085, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Okada
authors.affiliation: Equine Research Institute, Japan Racing Association, Tochigi 329-0412, Japan.
authors.forename: Taisuke
authors.initials: T
authors.lastname: Kuroda
authors.affiliation: Racehorse Clinic, Ritto Training Center, Japan Racing Association, Shiga 520-3085, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Wakuno
authors.affiliation: Equine Research Institute, Japan Racing Association, Tochigi 329-0412, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Ohta
keywords: anesthetic depth; bispectral index; horse; sevoflurane