title: The cardiopulmonary effects of a peripheral alpha-2-adrenoceptor antagonist, MK-467, in dogs sedated with a combination of medetomidine and butorphanol.
abstract: OBJECTIVE
  To compare the cardiopulmonary effects of intravenous (IV) and intramuscular (IM) medetomidine and butorphanol with or without MK-467.
  
  
  METHODS
  Prospective, randomized experimental cross-over.
  
  
  METHODS
  Eight purpose-bred beagles (two females, six males), 3-4 years old and weighing 14.5 ±1.6 kg (mean ± SD).
  
  
  METHODS
  All dogs received four different treatments as follows: medetomidine 20 μg kg(-1) and butorphanol tartrate 0.1 mg kg(-1) IV and IM (MB), and MB combined with MK-467,500 μg kg(-1) (MBMK) IV and IM. Heart rate (HR), arterial blood pressures (SAP, MAP, DAP), central venous pressure (CVP), cardiac output, respiratory rate (fR ), rectal temperature (RT) were measured and arterial blood samples were obtained for gas analysis at baseline and at 3, 10, 20, 30, 45 and 60 minutes after drug administration. The cardiac index (CI), systemic vascular resistance index (SVRI) and oxygen delivery index (DO2 I) were calculated. After the follow-up period atipamezole 50 μg kg(-1) IM was given to reverse sedation.
  
  
  RESULTS
  HR, CI and DO2 I were significantly higher with MBMK after both IV and IM administration. Similarly, SAP, MAP, DAP, CVP, SVRI and RT were significantly lower after MBMK than with MB. There were no differences in fR between treatments, but arterial partial pressure of oxygen decreased transiently after all treatments. Recoveries were uneventful following atipamezole administration after all treatments.
  
  
  CONCLUSIONS
  MK-467 attenuated the cardiovascular effects of a medetomidine-butorphanol combination after IV and IM administration.
authors.affiliation: Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
authors.forename: Kati
authors.initials: K
authors.lastname: Salla
authors.forename: Flavia
authors.initials: F
authors.lastname: Restitutti
authors.forename: Mari
authors.initials: M
authors.lastname: Vainionpää
authors.forename: Jouni
authors.initials: J
authors.lastname: Junnila
authors.forename: Juhana
authors.initials: J
authors.lastname: Honkavaara
authors.forename: Erja
authors.initials: E
authors.lastname: Kuusela
authors.forename: Marja
authors.initials: M
authors.lastname: Raekallio
authors.forename: Outi
authors.initials: O
authors.lastname: Vainio
mesh_terms: D058669:Adrenergic alpha-2 Receptor Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001784:Blood Gas Analysis / Q000662:veterinary; D001794:Blood Pressure / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D002077:Butorphanol / Q000008:administration & dosage / Q000494:pharmacology*; D002302:Cardiac Output / Q000187:drug effects; D018592:Cross-Over Studies; D004285:Dogs; D005260:Female; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology*; D007273:Injections, Intramuscular; D007275:Injections, Intravenous; D008168:Lung / Q000187:drug effects*; D008297:Male; D020926:Medetomidine / Q000008:administration & dosage / Q000494:pharmacology*; D011807:Quinolizines; D056152:Respiratory Rate / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D058669:Adrenergic alpha-2 Receptor Antagonists; D006993:Hypnotics and Sedatives; D011807:Quinolizines; C055732:vatinoxan; D020926:Medetomidine; D002077:Butorphanol
keywords: MK-467; butorphanol; dog; haemodynamics; medetomidine