Determination of Alfaxalone Dose for Co-Induction with Dexmedetomidine and the Clinical Efficacy in Cats

Objective: The study was aimed to investigate the dose of intravascular (IV) administration of alfaxalone alone or in combination with dexmedetomidine in cats. Sedative, anesthetic, and cardiorespiratory effects were evaluated during induction and OVH.Methods: Twelve male and twelve female healthy cats were divided into three groups: dexmedetomidine (5 μg/kg, IM) followed by alfaxalone, dexmedetomidine (5 μg/kg, IM), alfaxalone alone. Twelve female cats were induced by propofol (10 mg/kg, IV) or alfaxalone (5 mg/kg, IV) and maintained with isoflurane during ovariohysterectomy. Heart rate, arterial blood pressure, respiratory frequency, oxygen saturation, ETCO2, and BIS data were collected every 2 mins during induction and every 5 mins during OVH starting immediately after intubation.Results: The administration of dexmedetomidine prior to alfaxalone reduced the dose of intubation with alfaxalone by 50.9%. However, dexmedetomidine resulted in cardiovascular and respiratory depression. The BIS values during induction indicated that all twenty-four cats were only sedated and not suitable for surgery. The degree of cardiovascular and respiratory depression, the BIS values, the quality of induction and recovery was similar induced by alfaxalone or propofol.Conclusion: The IV administration of alfaxalone as a single agent in cats produced sedation with a stable cardiorespiratory function. Dexmedetomidine reduced the dose of alfaxalone and prevent the incidence of hyperkinesia during recovery, but resulted in some cardiorespiratory side effects. The BIS values during induction indicated that cats were only sedated and not suitable for surgery. The BIS values were maintained within a certain range during the OVH.