Infusion of guaifenesin, ketamine, and medetomidine in combination with inhalation of sevoflurane versus inhalation of sevoflurane alone for anesthesia of horses.
OBJECTIVE
To evaluate effects of infusion of guaifenesin, ketamine, and medetomidine in combination with inhalation of sevoflurane versus inhalation of sevoflurane alone for anesthesia of horses.


METHODS
Randomized clinical trial.


METHODS
40 horses.


METHODS
Horses were premedicated with xylazine and anesthetized with diazepam and ketamine. Anesthesia was maintained by infusion of guaifenesin, ketamine, and medetomidine and inhalation of sevoflurane (20 horses) or by inhalation of sevoflurane (20 horses). A surgical plane of anesthesia was maintained by controlling the inhaled concentration of sevoflurane. Sodium pentothal was administered as necessary to prevent movement in response to surgical stimulation. Hypotension was treated with dobutamine; hypoxemia and hypercarbia were treated with intermittent positive-pressure ventilation. The quality of anesthetic induction, maintenance, and recovery and the quality of the transition to inhalation anesthesia were scored.


RESULTS
The delivered concentration of sevoflurane (ie, the vaporizer dial setting) was significantly lower and the quality of transition to inhalation anesthesia and of anesthetic maintenance were significantly better in horses that received the guaifenesin-ketamine-medetomidine infusion than in horses that did not. Five horses, all of which received sevoflurane alone, required administration of pentothal. Recovery time and quality of recovery were not significantly different between groups, but horses that received the guaifenesin-ketamine-medetomidine infusion required fewer attempts to stand.


CONCLUSIONS
Results suggest that in horses, the combination of a guaifenesin-ketamine-medetomidine infusion and inhalation of sevoflurane resulted in better transition and maintenance phases while improving cardiovascular function and reducing the number of attempts needed to stand after the completion of anesthesia, compared with inhalation of sevoflurane.
Yamashita
Kazuto
K
Department of Veterinary Surgery 1, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan.
Muir
William W
WW
Tsubakishita
Sae
S
Abrahamsen
Eric
E
Lerch
Phillip
P
Izumisawa
Yasuharu
Y
Kotani
Tadao
T
D000758:Anesthesia / Q000379:methods / Q000662:veterinary*; D000762:Anesthesia Recovery Period; D019162:Anesthetics, Combined; D018685:Anesthetics, Inhalation; D000818:Animals; D005260:Female; D006140:Guaifenesin; D006736:Horses / Q000502:physiology*; D007649:Ketamine; D008297:Male; D020926:Medetomidine; D008738:Methyl Ethers; D011229:Preanesthetic Medication / Q000662:veterinary; D000077149:Sevoflurane
D019162:Anesthetics, Combined; D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane; D006140:Guaifenesin; D007649:Ketamine; D020926:Medetomidine