Anaesthetic Management Including Low-Dose Dexmedetomidine and Butorphanol in Dogs Undergoing ECG-Gated Cardiac Computed Tomography: A Retrospective Case Series.

This retrospective case series aims to assess the effects of an anaesthetic protocol including low-dose dexmedetomidine and butorphanol in dogs referred for cardiac tamponade undergoing ECG-gated CCT with contrast medium administration. Fifteen dogs (7 males, 8 females; ASA III/IV, body weight 25 ± 17.5 kg and age 8.6 ± 3.2 years) of different breeds with mild (n = 10/15) and moderate (n = 5/15) pericardial effusion were included. Pericardiocentesis was performed before anaesthesia. Dogs were premedicated with intravenous (IV) dexmedetomidine (0.5-1 μg kg-1) and butorphanol (0.1-0.3 mg kg-1). General anaesthesia was induced with propofol to effect (2-4.5 mg kg-1) IV and maintained with isoflurane in medical air and oxygen. During anaesthesia, heart rate and mean arterial pressure ranged from 37-141 beats min-1 and 58-117 mmHg respectively. No arrhythmias were recorded; mild hypotension occurred in two patients under general anaesthesia. No mortality was recorded within 48 h. Image quality was rated as excellent or good in most examinations, with moderate quality reported in two cases. A protocol including low-dose dexmedetomidine and butorphanol was feasible and was associated with acceptable recorded cardiovascular variables in this case series.