title: Effects of a continuous rate infusion of butorphanol in isoflurane-anesthetized horses on cardiorespiratory parameters, recovery quality, gastrointestinal motility and serum cortisol concentrations.
abstract: OBJECTIVE
  To assess the cardiorespiratory parametes, recovery, gastrointestinal motility and serum cortisol concentrations in horses anesthetized with isoflurane with or without a continuous rate infusion (CRI) of butorphanol for orchiectomy.
  
  
  METHODS
  Twelve adult, intact, male horses weighing 332 ± 55 kg were included in the study. Xilazine was administered as premedication. Anesthesia was induced with ketamine and midazolam and maintained with isoflurane. Butorphanol (0.025 mg kg-1 bolus) or an equivalent volume of saline (0.9%) was given intravenously followed by a CRI of butorphanol (BG) (13 µg kg-1 hour-1) or saline (CG). Cardiorespiratory variables were recorded before (T0) and every 15 minutes for 75 minutes after the start of infusion. Serum cortisol concentration was measured at T0 and 60 minutes, and 30 minutes and 19 hours after the horse stood up. Recovery from anesthesia was evaluated using a scoring system. Gastrointestinal motility was evaluated before anesthesia and during 24 hours after recovery.
  
  
  RESULTS
  There were no significant differences between groups in cardiopulmonary variables, or recovery scores or serum cortisol concentrations. A reduction in gastrointestinal motility was recorded for 60 minutes in BG.
  
  
  CONCLUSIONS
  Continuous rate infusion of butorphanol in horses anesthetized with isoflurane did not adversely affect the cardiopulmonary variables monitored, or recovery scores. A small but statistically significant reduction in gastrointestinal motility occurred in the butorphanol group.
authors.affiliation: Faculty of Veterinary Medicine, Sao Paulo State University, Araçatuba, SP, Brazil.
authors.forename: Bianca Paludeto
authors.initials: BP
authors.lastname: Dias
authors.affiliation: Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul, Campo Grande, MS, Brazil.
authors.forename: Marcelo Augusto de
authors.initials: MA
authors.lastname: Araújo
authors.affiliation: Faculty of Veterinary Medicine, UNESP, Araçatuba, SP, Brazil.
authors.forename: Maurício
authors.initials: M
authors.lastname: Deschk
authors.affiliation: Faculty of Veterinary Medicine, UNESP, Araçatuba, SP, Brazil.
authors.forename: Thomas Alexander
authors.initials: TA
authors.lastname: Trein
authors.affiliation: Department of Clinical, Surgey and Animal Reproduction, Faculty of Veterinary Medicine, UNESP, Araçatuba, SP, Acquisition.
authors.forename: Nirmem Carlos
authors.initials: NC
authors.lastname: Pinheiro
authors.affiliation: Department of Support, Animal Production and Health, Faculty of Veterinary Medicine, UNESP, Araçatuba, SP, Brazil.
authors.forename: Silvia Helena Venturolli
authors.initials: SH
authors.lastname: Perri
authors.affiliation: Department of Surgery and Anesthesiology, Faculty of Veterinary Medicine, UNESP, Botucatu, SP, Brazil.
authors.forename: Celso Antônio
authors.initials: CA
authors.lastname: Rodrigues
authors.affiliation: Department of Clinical, Surgery and Animal Reproduction, Faculty of Veterinary Medicine, UNESP, Araçatuba, SP, Brazil.
authors.forename: Paulo Sergio Patto dos
authors.initials: PS
authors.lastname: Santos
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology*; D000762:Anesthesia Recovery Period; D000769:Anesthesia, Inhalation / Q000662:veterinary; D000818:Animals; D002077:Butorphanol / Q000008:administration & dosage / Q000494:pharmacology*; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D006736:Horses; D006854:Hydrocortisone / Q000097:blood; D007260:Infusion Pumps; D007262:Infusions, Intravenous / Q000662:veterinary; D007530:Isoflurane / Q000008:administration & dosage; D008297:Male; D023421:Models, Animal; D009919:Orchiectomy / Q000662:veterinary; D011897:Random Allocation; D056152:Respiratory Rate / Q000187:drug effects*; D013997:Time Factors
chemical_list: D000701:Analgesics, Opioid; D007530:Isoflurane; D002077:Butorphanol; D006854:Hydrocortisone