Characterization of the anesthetic effects of dexmedetomidine-vatinoxan-ketamine combinations in cats

Objective To characterize the anesthetic effects of dexmedetomidine, vatinoxan and ketamine combinations in cats. Study design Randomized crossover experimental study. Animals A group of seven healthy male neutered cats, with body mass 5.2 +/- 0.4 kg and aged 1-2 years. Methods Cats were implanted with a telemetric transmitter for remote recording of mean arterial pressure and heart rate before beginning the study. Each cat received a total of six treatments, coadministered in a single syringe, each at least 2 weeks apart: dexmedetomidine (25 mg kg-1, D) + vatinoxan (600 mg kg-1, V) + ketamine (2.5 mg kg-1, K2.5) intramuscularly (IM) (DVK2.5IM); D + V + ketamine (5 mg kg-1, K5) IM (DVK5IM); D + V + ketamine (10 mg kg-1, K10) IM (DVK10IM); D + K5 IM (DK5IM); D + V + K5 subcutaneously (SC) (DVK5SC); or D + V + K5 intravenously (IV) (DVK5IV). Select physiologic variables and time to recumbency, immobilization, first movement, head lift, return to sternal recumbency and walking were recorded. Quality of sedation/anesthesia was assessed using a visual analog score. Response to noxious electrical stimulation was assessed at 10 minute intervals. Results Heart rate (beats minute-1) was significantly greater in DVK5IM (overall mean +/- standard deviation 142 +/- 19) than in DK5IM (115 +/- 16). No treatment consistently prevented movement in response to noxious stimulation. Time to first movement was significantly shorter in DVK2.5IM (45 +/- 10 minutes) than in DVK10IM (93 +/- 25 minutes), and in DVK5IM (53 +/- 12 minutes) than in DK5IM (95 +/- 39 minutes). Conclusions and clinical relevance Dexmedetomidine- vatinoxan-ketamine combinations, at the doses studied, may be useful to produce sedation, but do not appear to consistently produce anesthesia as characterized by immobility in response to noxious stimulation.