Dexmedetomidine Related Bradycardia Leading to Cardiac Arrest in a Dog

A 2-year-old, mixed breed female dog (16 kg) underwent an exploratory laparotomy following ultrasonographic diagnosis of foreign body and a segment of small intestine intussusceptions. The patient was classified as an ASA II. Ketamine (1mg/kg, IV), and dexmedetomidine (2.5 μg/kg, IV), and morphine (0.6 mg/kg, SC) were given as anesthetic premedication. Propofol (0.1 mg/kg, IV) titrated to a total amount of 4 ml (2.5 mg/ kg) was given for intubation. Asystole was occurred. Cardiac resuscitation was then conducted immediately. Atipamezole (0.1 ml) was injected, but showed no response on ECG. Atropine (0.02 mg/kg) was then injected, and a second dosage was given. Two-three mins later, the heart rate at 84 beats/min. The NIBP showed 203/132 with MAP 153 mmHg, and the SpO2 showed 95% after the cardiac function was regained. Dexmedetomidine related bradycardia leading to cardiac arrest has been suggested in this case.