title: Effects of a constant rate infusion of detomidine on cardiovascular function, isoflurane requirements and recovery quality in horses.
abstract: OBJECTIVE
  To examine the influence of a detomidine constant rate infusion (CRI) on cardiovascular function, isoflurane requirements and recovery quality in horses undergoing elective surgery.
  
  
  METHODS
  Prospective, randomized, blinded, clinical trial.
  
  
  METHODS
  Twenty adult healthy horses.
  
  
  METHODS
  After sedation (detomidine, 10 μg kg(-1) intravenously [IV]) and induction of anaesthesia (midazolam 0.06 mg kg(-1) , ketamine 2.2 mg kg(-1) IV), anaesthesia was maintained with isoflurane in oxygen/air (inspiratory oxygen fraction 55%). When indicated, the lungs were mechanically ventilated. Dobutamine was administered when MAP<70 mmHg. The horses were randomly allocated to one of two groups and throughout anaesthesia, received either a detomidine (5 μg kg(-1)  hour(-1) ) (D) or saline (S) CRI, with the anaesthetist unaware of the treatment. Monitoring included end-tidal isoflurane concentration, arterial pH, PaCO(2) , PaO(2) , dobutamine administration rate, heart rate (HR), arterial pressure, cardiac index (CI), systemic vascular resistance (SVR), stroke index and oxygen delivery index (ḊO(2) I). For recovery from anaesthesia, all horses received 2.5 μg kg(-1) detomidine IV. Recovery quality and duration were recorded in each horse. For statistical analysis, anova, Pearson chi-square and Wilcoxon rank sum tests were used as relevant.
  
  
  RESULTS
  Heart rate (p=0.0176) and ḊO(2) I (p= 0.0084) were lower and SVR higher (p=0.0126) in group D, compared to group S. Heart rate (p=0.0011) and pH (p=0.0187) increased over time. Significant differences in isoflurane requirements were not detected. Recovery quality and duration were comparable between treatments.
  
  
  CONCLUSIONS
  A detomidine CRI produced cardiovascular effects typical for α(2) -agonists, without affecting isoflurane requirements, recovery duration or recovery quality.
authors: Department of Surgery and Anaesthesia of Domestic Animals, Faculty of Veterinary Medicine, University of Ghent, Merelbeke, Belgium. stijn.schauvliege@UGent.be
authors: Stijn
authors: S
authors: Schauvliege
authors: Miguel Gozalo
authors: MG
authors: Marcilla
authors: Kirsten
authors: K
authors: Verryken
authors: Luc
authors: L
authors: Duchateau
authors: Lindsey
authors: L
authors: Devisscher
authors: Frank
authors: F
authors: Gasthuys
mesh_terms: D000762:Anesthesia Recovery Period; D000769:Anesthesia, Inhalation / Q000662:veterinary*; D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D000818:Animals; D017558:Elective Surgical Procedures / Q000662:veterinary; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D006736:Horses / Q000601:surgery*; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology*; D007093:Imidazoles / Q000008:administration & dosage / Q000494:pharmacology*; D007262:Infusions, Intravenous / Q000662:veterinary; D007530:Isoflurane / Q000008:administration & dosage*; D008297:Male; D011446:Prospective Studies; D016037:Single-Blind Method
chemical_list: D018685:Anesthetics, Inhalation; D006993:Hypnotics and Sedatives; D007093:Imidazoles; C041255:detomidine; D007530:Isoflurane