title: Effects of subanesthetic doses of ketamine on hemodynamic and immunologic variables in dogs with experimentally induced endotoxemia.
abstract: OBJECTIVE
  To determine the effects of ketamine hydrochloride on hemodynamic and immunologic alterations associated with experimentally induced endotoxemia in dogs.
  
  
  METHODS
  9 mixed-breed dogs.
  
  
  METHODS
  In a crossover study, dogs were randomly allocated to receive ketamine (0.5 mg/kg, IV, followed by IV infusion at a rate of 0.12 mg/kg/h for 2.5 hours) or control solution (saline [0.9% NaCl] solution, 0.25 mL, IV, followed by IV infusion at a rate of 0.5 mL/h for 2.5 hours). Onset of infusion was time 0. At 30 minutes, lipopolysaccharide (LPS; 1 microg/kg, IV) was administered. Heart rate (HR), systolic arterial blood pressure (SAP), plasma tumor necrosis factor (TNF)-alpha activity, and a CBC were evaluated.
  
  
  RESULTS
  Mean SAP was significantly reduced in dogs administered ketamine or saline solution at 2 and 2.5 hours, compared with values at time 0. However, there was no significant difference between treatments. At 1, 2, and 2.5 hours, dogs administered ketamine had a significantly lower HR than dogs administered saline solution. Although plasma TNF-alpha activity significantly increased, compared with values at time 0 for both groups, ketamine-treated dogs had significantly lower peak plasma TNF-alpha activity 1.5 hours after LPS administration. All dogs had significant leukopenia and neutropenia after LPS administration, with no differences detected between ketamine and saline solution treatments.
  
  
  CONCLUSIONS
  Administration of a subanesthetic dose of ketamine had immunomodulating effects in dogs with experimentally induced endotoxemia (namely, blunting of plasma TNF-alpha activity). However, it had little effect on hemodynamic stability and no effect on WBC counts.
authors.affiliation: Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA.
authors.forename: Amy E
authors.initials: AE
authors.lastname: DeClue
authors.forename: Leah A
authors.initials: LA
authors.lastname: Cohn
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Lechner
authors.forename: Margaret E
authors.initials: ME
authors.lastname: Bryan
authors.forename: John R
authors.initials: JR
authors.lastname: Dodam
mesh_terms: D000777:Anesthetics / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D018592:Cross-Over Studies; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D019446:Endotoxemia / Q000139:chemically induced / Q000188:drug therapy / Q000662:veterinary*; D006339:Heart Rate / Q000187:drug effects*; D007649:Ketamine / Q000494:pharmacology*; D007962:Leukocytes / Q000187:drug effects; D009504:Neutrophils / Q000187:drug effects; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000777:Anesthetics; D014409:Tumor Necrosis Factor-alpha; D007649:Ketamine