Comparison of sevoflurane and isoflurane in dogs anaesthetised for clinical surgical or diagnostic procedures.

Objectives: To assess attributes of sevoflurane for routine clinical anaesthesia in dogs by comparison with the established volatile anaesthetic isoflurane. Methods: One hundred and eight dogs requiring anaesthesia for elective surgery or diagnostic procedures were studied. The majority was premedicated with 0·03 mg/kg of acepromazine and 0·01 mg/kg of buprenorphine or 0·3 mg/kg of methadone before induction of anaesthesia with 2 to 4 mg/kg of propofol and 0·5 mg/kg of diazepam. They were randomly assigned to receive either sevoflurane (group S, n=50) or isoflurane (group I, n=58) in oxygen and nitrous oxide for maintenance of anaesthesia. Heart rate, respiratory rate, indirect arterial blood pressure, haemoglobin saturation, vaporiser settings, end-tidal carbon dioxide and anaesthetic concentration and oesophageal temperature were measured. Recovery was timed. Data were analysed using analysis of variance and non-parametric tests. Results: Heart rate (85 to 140/minute), respiratory rate (six to 27/minute) and systolic arterial blood pressure (80 to 150 mmHg) were similar in the two groups. End-tidal carbon dioxide between 30 and 60 minutes (group S 6·4 to 6·6 and group I 5·8 to 5·9 per cent) and vaporiser settings throughout (group S 2·1 to 2·9 and group I 1·5 to 1·5 per cent) were higher in group S. There was no difference in time to head lift (18±16 minutes), sternal recumbency (28±22 minutes) or standing (48±32 minutes). No adverse events occurred. Clinical Significance: Sevoflurane appeared to be a suitable volatile anaesthetic for maintenance of routine clinical anaesthesia in dogs. [ABSTRACT FROM AUTHOR]