title: A comparison of 3 anesthetic protocols for 24 hours of mechanical ventilation in cats.
abstract: OBJECTIVE
  To compare the recovery times, recovery quality, and cardiovascular (CV) effects of 3 anesthetic protocols during 24 hours of mechanical ventilation (MV) in healthy cats.
  
  
  METHODS
  Prospective, randomized, crossover study.
  
  
  METHODS
  Research laboratory at a veterinary teaching hospital.
  
  
  METHODS
  Six healthy intact male purpose-bred cats.
  
  
  METHODS
  Each cat was randomly assigned to receive 3 anesthetic protocols for 24 hours of MV; Protocol K consisted of ketamine, Protocol P, propofol; and Protocol PK, propofol plus fixed-rate low-dose ketamine. Each infusion drug dose was adjusted using a sedation scoring system. All protocols included fixed doses of fentanyl (10 μg/kg/h) and midazolam (0.5 mg/kg/h).
  
  
  RESULTS
  Drug doses and recovery times were recorded. Recovery quality was scored. Blood gas results, CV parameters, and frequency of bradycardia or hypotension requiring interventions were recorded. The mean d dose ± standard error of K was 81.3 ± 3.3 μg/kg/m. The median dose (95% cardiac index) of propofol (μg/kg/m) in PK was 16.0 (13.1, 19.6) and in P was 48.1 (39.3, 58.9). P necessitated significantly more propofol than PK (P < 0.05). Protocol K (35.6 ± 3.2 hours) had significantly longer times to full recovery compared to P (18.2 ± 3.2 hours). Protocol K had significantly longer times to head up, crawling, and standing compared to P and PK. Cats sedated with PK (2.33 ± 0.47) required significantly more interventions for hypotension than K (0.50 ± 0.47). Protocol P (3.2 ± 0.4) and PK (1.4 ± 0.3) required significantly more interventions for bradycardia compared to K (0.8 ± 0.3). When comparing protocol K to P and PK, significant differences in blood pressure, lactate, oxygen delivery, and oxygen consumption were noted.
  
  
  CONCLUSIONS
  Cats anesthetized with P had shorter times to full recovery compared to K. Cats anesthetized with K required fewer interventions for bradycardia or hypotension but had longer recovery times compared to P or PK. Protocol PK reduced the propofol dose required to maintain optimal anesthesia.
authors.affiliation: Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada. aboudrea@uoguelph.ca
authors.forename: Ainsley E
authors.initials: AE
authors.lastname: Boudreau
authors.forename: Alexa M E
authors.initials: AM
authors.lastname: Bersenas
authors.forename: Carolyn L
authors.initials: CL
authors.lastname: Kerr
authors.forename: Marie K
authors.initials: MK
authors.lastname: Holowaychuk
authors.forename: Ron J
authors.initials: RJ
authors.lastname: Johnson
mesh_terms: D000762:Anesthesia Recovery Period; D000771:Anesthesia, Intravenous / Q000662:veterinary*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000009:adverse effects; D000818:Animals; D002415:Cats / Q000502:physiology*; D018592:Cross-Over Studies; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005283:Fentanyl; D007022:Hypotension / Q000139:chemically induced / Q000662:veterinary; D007649:Ketamine / Q000008:administration & dosage / Q000009:adverse effects; D008297:Male; D008874:Midazolam; D015742:Propofol / Q000008:administration & dosage / Q000009:adverse effects; D012121:Respiration, Artificial / Q000662:veterinary*; D013047:Specific Pathogen-Free Organisms
chemical_list: D018686:Anesthetics, Intravenous; D007649:Ketamine; D008874:Midazolam; D005283:Fentanyl; D015742:Propofol