Comparison of sedation with dexmedetomidine/atipamezole administered subcutaneously at GV20 acupuncture point with usual routes of administration in dogs presented for orthopaedic radiographs

Abstract

Objectives: To evaluate the efficacy of subcutaneous administration of dexmedetomidine/atipamezole at the Governing Vessel 20 (GV20) acupuncture point compared with other administration routes (intramuscular and intravenous) in dogs presented for orthopaedic radiographs. Materials and Methods: Prospective, randomised, blinded, controlled clinical study. Sixty-four client-owned dogs were randomly injected with 200 μg/m2 of dexmedetomidine intramuscular (lumbar muscles) (n=20), intravenous (n=23) or subcutaneous at the GV20 point (n=21). Following radiographs, dogs received 2000 μg/m2 of atipamezole intramuscular (n=31), or subcutaneous at the GV20 point (n=27). Degree and time to sedation and recovery were assessed using a sedation scale and a Dynamic and Interactive Visual Analog Scale (DIVAS). Clinical physiological variables and adverse events were used. Statistical linear mixed-effect models (analysis of variance) and Cox models were performed. Significance was set at P-value <0.05. Results: Sedation was insufficient to perform orthopaedic radiographs in six dogs in the intramuscular group. The time to sedation was significantly longer, and sedation scale and DIVAS scores were significantly lower in the intramuscular group. The intravenous group had significantly higher sedation scale and DIVAS scores than the GV20 group. No significant differences were observed between the intramuscular and GV20 recovery groups, although the time effect was significantly more pronounced in the GV20 recovery group. Clinical Significance: Subcutaneous administration of dexmedetomidine and atipamezole at GV20 provided effective sedation and recovery in dogs undergoing orthopaedic radiographic studies. GV20 administration provided a clinically similar level of sedation to the intravenous route, and greater and faster sedation and similar recovery to intramuscular.