title: Comparison of the effects of propofol or alfaxalone for anaesthesia induction and maintenance on respiration in cats.
abstract: OBJECTIVE
  To compare the effects of propofol and alfaxalone on respiration in cats.
  
  
  METHODS
  Randomized, 'blinded', prospective clinical trial.
  
  
  METHODS
  Twenty cats undergoing ovariohysterectomy.
  
  
  METHODS
  After premedication with medetomidine 0.01 mg kg(-1) intramuscularly and meloxicam 0.3 mg kg(-1) subcutaneously, the cats were assigned randomly into two groups: group A (n = 10) were administered alfaxalone 5 mg kg(-1)  minute(-1) followed by 10 mg kg(-1)  hour(-1) intravenously (IV) and group P (n = 10) were administered propofol 6 mg kg(-1 ) minute(-1) followed by 12 mg kg(-1) hour(-1) IV for induction and maintenance of anaesthesia, respectively. After endotracheal intubation, the tube was connected to a non-rebreathing system delivering 100% oxygen. The anaesthetic maintenance drug rate was adjusted (± 0.5 mg kg(-1) hour(-1) ) every 5 minutes according to a scoring sheet based on physiologic variables and clinical signs. If apnoea > 30 seconds, end-tidal carbon dioxide (Pe'CO2 ) > 7.3 kPa (55 mmHg) or arterial haemoglobin oxygen saturation (SpO2 ) < 90% occurred, manual ventilation was provided. Methadone was administered postoperatively. Data were analyzed using independent-samples t-tests, Fisher's exact test, linear mixed-effects models and binomial test.
  
  
  RESULTS
  Manual ventilation was required in two and eight of the cats in group A and P, respectively (p = 0.02). Two cats in both groups showed apnoea. Pe'CO2  > 7.3 kPa was recorded in zero versus four and SpO2  < 90% in zero versus six cats in groups A and P respectively. Induction and maintenance dose rates (mean ± SD) were 11.6 ± 0.3 mg kg(-1) and 10.7 ± 0.8 mg kg(-1)  hour(-1) for alfaxalone and 11.7 ± 2.7 mg kg(-1) and 12.4 ± 0.5 mg kg(-1) hour(-1) for propofol.
  
  
  CONCLUSIONS
  Alfaxalone had less adverse influence on respiration than propofol in cats premedicated with medetomidine. Alfaxalone might be better than propofol for induction and maintenance of anaesthesia when artificial ventilation cannot be provided.
authors.affiliation: Division of Anaesthesiology, Equine Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
authors.forename: Ivo
authors.initials: I
authors.lastname: Campagna
authors.affiliation: Division of Anaesthesiology, Equine Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
authors.forename: Andrea
authors.initials: A
authors.lastname: Schwarz
authors.affiliation: Section of Small Animal Reproduction, Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Keller
authors.affiliation: Division of Anaesthesiology, Equine Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
authors.forename: Regula
authors.initials: R
authors.lastname: Bettschart-Wolfensberger
authors.affiliation: Division of Anaesthesiology, Equine Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
authors.forename: Martina
authors.initials: M
authors.lastname: Mosing
mesh_terms: D000762:Anesthesia Recovery Period; D000771:Anesthesia, Intravenous / Q000662:veterinary; D018686:Anesthetics, Intravenous / Q000008:administration & dosage*; D000818:Animals; D002415:Cats / Q000502:physiology*; D004311:Double-Blind Method; D005260:Female; D007044:Hysterectomy / Q000662:veterinary; D010052:Ovariectomy / Q000662:veterinary; D011277:Pregnanediones / Q000008:administration & dosage*; D015742:Propofol / Q000008:administration & dosage*; D011446:Prospective Studies; D012119:Respiration / Q000187:drug effects*; D016896:Treatment Outcome
chemical_list: D018686:Anesthetics, Intravenous; D011277:Pregnanediones; C006477:alphaxalone; D015742:Propofol
keywords: continuous rate infusion; feline; respiration; total intravenous anaesthesia; ventilation