title: Prevalence of dysphoria after fentanyl in dogs undergoing stifle surgery.
abstract: OBJECTIVE
  To describe the prevalence of dysphoria after intraoperative administration of fentanyl by infusion and identify other risk factors influencing this in dogs undergoing stifle surgery.
  
  
  METHODS
  Prospective, randomized clinical study.
  
  
  METHODS
  Dogs (n = 92) that had tibial plateau leveling osteotomy (TPLO) or tibial tuberosity advancement (TTA).
  
  
  METHODS
  Dogs were anesthetized using a standardized anesthetic protocol, and randomly assigned to receive a loading dose followed by 1 of 3 infusions of fentanyl perioperatively: 2 μg/kg/h, 10 μg/kg/h, or 20 μg/kg/h. Dog characteristics and all additional medications were recorded and included as part of the statistical analysis. Dog behavior was scored before anesthesia and during recovery using a scale of 1-4 (Appendices A and B). If no improvement in behavior was seen in 3-5 minutes postextubation, dogs with a score of 3 or 4 during recovery were administered fentanyl (2 μg/kg intravenously [IV]) in the event that the behaviors associated with the higher scores were related to pain. If they did not respond favorably to the administration of additional fentanyl and wound palpation did not elicit a response, but the untoward behaviors continued, dogs were administered either a tranquilizer, sedative, or opioid antagonist, and were considered dysphoric.
  
  
  RESULTS
  Of 92 dogs, 22 (23.9%) were considered dysphoric using aforementioned criteria.
  
  
  CONCLUSIONS
  About one-fourth of dogs enrolled in this study were dysphoric based on study criteria.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA.
authors.forename: Willem M
authors.initials: WM
authors.lastname: Becker
authors.forename: Khursheed R
authors.initials: KR
authors.lastname: Mama
authors.forename: Sangeeta
authors.initials: S
authors.lastname: Rao
authors.forename: Ross H
authors.initials: RH
authors.lastname: Palmer
authors.forename: Erick L
authors.initials: EL
authors.lastname: Egger
mesh_terms: D000701:Analgesics, Opioid / Q000009:adverse effects*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D004283:Dog Diseases / Q000139:chemically induced / Q000601:surgery*; D004285:Dogs; D005260:Female; D005283:Fentanyl / Q000009:adverse effects*; D008297:Male; D010027:Osteotomy / Q000009:adverse effects / Q000379:methods / Q000662:veterinary; D012307:Risk Factors; D013264:Stifle / Q000601:surgery*
chemical_list: D000701:Analgesics, Opioid; D005283:Fentanyl