title: Comparison of the cardiopulmonary parameters after induction of anaesthesia with alphaxalone or etomidate in dogs.
abstract: OBJECTIVE
  To compare the cardiorespiratory effects and quality of induction of and recovery from anaesthesia following etomidate or alphaxalone-HPCD IV.
  
  
  METHODS
  Randomized 'blinded' cross-over study. Twenty-four hours was allowed between phases.
  
  
  METHODS
  Eight healthy adult Beagles (four male, four female).
  
  
  METHODS
  Dogs were anaesthetized with sevoflurane for instrumentation, then allowed to awake. They then received etomidate (treatment E) or alphaxalone-HPCD (treatment A) intravenously to effect. Heart rate (HR), body temperature, invasive arterial pressures (AP), systemic vascular resistance index (SVRI), stroke volume index, cardiac index (CI), contractility, respiratory rate, central venous pressure, and capnometry were obtained before anaesthetic induction (baseline), 30 seconds and 1 minute after induction, after intubation, one minute after intubation, and for every 5 minutes afterwards until the dog began to swallow and the trachea was extubated. Arterial bloods were taken for analyses before induction, after intubation and every 10 minutes thereafter. The dogs breathed room air. The quality of induction of and recovery from anaesthesia were scored categorically. Statistical analyses used anova for repeated measures, paired t-tests or Wilcoxon signed rank-test as relevant. Significance was set at p < 0.05.
  
  
  RESULTS
  The induction doses required were (mean ± SD) 2.91 ± 0.41 mg kg(-1) and 4.15 ± 0.7 mg kg(-1) for treatment E and A respectively. No significant changes in cardiovascular parameters were observed with treatment E. Treatment A resulted in statistically significant increases in HR and CI and reductions of APs and SVRI. Time to extubation was longer with treatment A (25 ± 7 minutes) than with treatment E (17 ± 4 minutes). Dogs became hypoxic with both treatments. The quality of induction and recovery were excellent with treatment A, but significantly less satisfactory with treatment E (recovery score, treatment E median 1, range 0-2; treatment A median 0, range 0-1).
  
  
  CONCLUSIONS
  Alphaxalone-HPCD caused significant tachycardia and increase in CI, and statistically (but not clinically) significant decreases in APs and SVRI. Etomidate caused no statistically significant cardiovascular changes. Quality of recovery was better with alfaxalone-HPCD. Both agents caused short-lived hypoxia, and oxygen supplementation is advisable.
authors.affiliation: Department of Animal Medicine and Surgery, University of Córdoba, Córdoba, Spain. v92moroj@uco.es
authors.forename: Juan Morgaz
authors.initials: JM
authors.lastname: Rodríguez
authors.forename: Pilar
authors.initials: P
authors.lastname: Muñoz-Rascón
authors.forename: Rocío
authors.initials: R
authors.lastname: Navarrete-Calvo
authors.forename: Rafael J
authors.initials: RJ
authors.lastname: Gómez-Villamandos
authors.forename: Juan M
authors.initials: JM
authors.lastname: Domínguez Pérez
authors.forename: Jose A
authors.initials: JA
authors.lastname: Fernández Sarmiento
authors.forename: Setefilla
authors.initials: S
authors.lastname: Quirós Carmona
authors.forename: María M
authors.initials: MM
authors.lastname: Granados Machuca
mesh_terms: D000771:Anesthesia, Intravenous / Q000379:methods / Q000662:veterinary*; D000818:Animals; D001785:Blood Gas Monitoring, Transcutaneous / Q000662:veterinary; D001794:Blood Pressure / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D004285:Dogs; D005045:Etomidate / Q000494:pharmacology*; D005260:Female; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects; D008168:Lung / Q000187:drug effects* / Q000502:physiology; D008297:Male; D011277:Pregnanediones / Q000494:pharmacology*; D056152:Respiratory Rate / Q000187:drug effects; D013318:Stroke Volume / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D011277:Pregnanediones; C006477:alphaxalone; D005045:Etomidate