Abstract:
A 10-month-old, 580 kg, hand-reared white rhinoceros (Ceratotherium simum) calf was presented for emergency exploratory celiotomy. Anaesthesia was safely induced with three successive intravenous (IV) boluses of diazepam (10 mg) and ketamine (100 mg) until the trachea could be intubated. Anaesthesia was adequately maintained with isoflurane-inoxygen (mean end-tidal isoflurane concentration of 1.1% ± 0.2%) on a circle anaesthetic machine with carbon dioxide absorption and an intravenous infusion of ketamine and medetomidine at a mean rate of 0.02 mg/kg/min and 0.02 µg/kg/min, respectively. Mean values recorded during anaesthesia and surgery were heart rate (56.9 ± 11 beats/min), mean arterial blood pressure (6.16 kPa ± 1.75 kPa), end-tidal carbon dioxide concentration (6.23 kPa ± 0.30 kPa). Abdominal gas distension contributed to hypoventilation that resulted in hypercapnoea, confirmed by arterial blood gas analysis (PaCO2 14.69 kPa), which required controlled ventilation for correction. Blood volume was maintained with the intravenous infusion of a balanced electrolyte solution at 10 mL/kg/h and blood pressure supported with a continuous infusion of dobutamine and phenylephrine. Duration of anaesthesia was 3.5 h. It was concluded that anaesthesia was safely induced in a compromised white rhinoceros calf with a combination of diazepam and ketamine. A constant-rate infusion of medetomidine and ketamine allowed for a reduction in the dose of isoflurane required during maintenance of anaesthesia and improved intra-operative blood pressure management.
